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> Persuading Your
Cat to Eat
Overview
-
If you still need help, this page provides tips on using foods to help your cat
maintain or gain weight, tempting your cat to eat, how to assist feed if
necessary, and the pros and cons of appetite stimulants.
Why Getting Food Into Your Cat is So Important
11 guidelines for conservatively treating chronic
kidney disease
(2007) Polzin D
Veterinary Medicine Dec 2007 states that "in
many or most dogs and cats with chronic kidney disease, death or euthanasia
results directly or indirectly from starvation."
This is truly shocking, not least because it is so unnecessary. Are you
really going to let your cat starve to death? I doubt it!
In! Getting calories in: feeding the inappetent or
anorectic cat
(2012) Scherk M
Presentation to the 73rd SCIVAC International Congress 2012
p431-432 is an excellent article about how to persuade your cat to eat.
Hepatic Lipidosis
Cats who do not eat may develop a very
serious condition called
hepatic lipidosis (fatty liver disease) where the
liver starts to function abnormally. Hepatic lipidosis can happen after just a day or two
of not eating and can be life-threatening.
The American Animal Hospital Association
recommends that you should contact your vet if your cat has not eaten for
one or two days.
Mar Vista Vet
has some information about hepatic lipidosis, and mentions that a cat who
has eaten only half to three quarters of his or her normal food intake for
two weeks is also at risk.
Most cats who develop hepatic lipidosis
require enteral nutrition (feeding via a tube).
Association of time to start of enteral nutrition and outcome in cats with
hepatic lipidosis (2024) Wallace OP, Jablonski SA, Thomas JS, III JH & Langlois
DK Journal of Veterinary Internal Medicine 38(6)
pp3144-3152 found that delaying fitting a feeding tube until more than
twelve hours after admission to hospital (which may happen while the cat is
stabilised) did not make a difference to chances of survival.
Hospitalisation is ideal so the patient
can be closely monitored but do not worry if you cannot afford it because
feeding tubes can also be used at home.
Hepatic lipidosis in a cat (2025) Rehse T &
Pohlman LM Clinician's Brief reports on a cat who developed hepatic
lipidosis and her at home treatment plan. Pumpkin made a full recovery.
So remember your new
mantra: my cat is going to eat!
Reasons for Loss of Appetite
If your cat does not want to eat,
please do try to find the cause (such as nausea, dehydration
and/or anaemia). You can check the
Index of
Symptoms and Treatments (scroll down to Appetite
Loss) for more information on
possible causes of inappetence. Treating whichever of these potential causes
is present is essential, and may even solve the problem for you.
However,
your cat needs to eat whilst you are sorting out the possible causes of
inappetence.
Plus even
after treating whatever problems
may be present, since cats eat to live rather than the other way
round, you may find your cat has got out of the habit of eating and has to
be tempted into doing so again. The good news is, once you have got your cat eating again, s/he may
feel better for it and soon get back into the habit.
If a cat is truly dying, the digestive process will cease to function and
the cat will not need food. If you fear this time has come, you will not
only see a refusal to eat but many other symptoms as well — check out
The Final Hours for
more information. But please don't assume your cat is dying simply because
s/he won't eat! Not eating is one of the most common symptoms in CKD cats,
and
appetite can come and go, so don't fear the worst just because you see this
symptom. For the vast majority of CKD cats, food is essential and part of
the treatment plan, and many people are amazed when they see how much better
their cat looks and feels once s/he has taken in some food.
Please see the
Nutritional Requirements
page for an explanation of your cat's physiological needs and a discussion
of the reduced
protein debate, and the
Which Foods to Feed
page for what to do if your cat refuses to eat the therapeutic kidney diet
that
your vet recommends.
Managing the cat that won't eat
(2022) International Cat Care discusses inappetence
and how to encourage your cat to eat.
Feline Calorie Needs
Whilst it is hard to be precise, a cat
needs approximately 30-35 calories per day per pound of body weight, or
possibly more if the cat is particularly active. As an example, a 9 lb cat
would need 270-315 calories a day. Therefore, as you can see, feeding a
teaspoonful of food a day is not going to be enough to maintain your cat's
weight, let alone increase it if your cat is too thin.
However, this level of intake is unlikely to be sufficient for older
cats.
Feeding older cats - an update in new nutritional therapies
(2011) Sparkes A Topics in Companion Animal Medicine
26(1) pp37-42 states that older cats need more calories than
younger cats, preferably in the form of protein.
Calories matter. If you are just trying
to get food into a cat who isn't eating much voluntarily, it makes sense to
use a calorie- and nutrient-dense food if at all possible. There is
information below about foods that your cat may be prepared to eat which
provide additional nourishment.
Please read more about the calorie needs
of CKD cats
here.
The First Thing to Try: Vitamin B
Your cat will probably benefit from
vitamin B supplements in the form of vitamin B complex and a separate vitamin
B12 supplement. Many people find these help their cats with appetite and
wellbeing, and they are widely available and very safe, though of course you
should not use them without your vet's knowledge (many vets, including mine,
offer these routinely).
Please see
below and the separate
Vitamin B page for more
information on suitable brands.
Additional Nourishment
This section covers foods that taste good to many cats
(so they may be prepared to eat them on their own) but that can also help
keep them going at times of crisis, or enable them to gain weight if they
need to do so.
Baby food
Meat or fish pastes
Human food
Fancy
Feast
Nutri-Cal
Eggs, Particularly Egg Whites
Egg Benefits
If you want to provide your cat
with additional nourishment, the best choice is probably eggs, which contain
high quality protein from a CKD perspective (see
Nutritional Requirements for more about this concept).
Washington State University College of Veterinary
Medicine says:
"Proteins with high biologic value can be readily converted to body proteins
with minimal waste production. Animal proteins have a higher biologic value
than vegetable proteins. Eggs have the highest biologic value."
There is more about this concept of here.
For a CKD cat, the egg white alone is
usually a better choice, because this provides additional
protein but does not contain high levels of phosphorus. According to the
US Department of Agriculture FoodData Central,
one large egg white weighs about 33g and contains 19 calories, 3.64g protein,
no fat and only 5mg of phosphorus. This is a lot less phosphorus than a chicken
breast, and the protein in eggs is more digestible.
A
human study,
Organic and inorganic dietary phosphorus and its management in chronic
kidney disease (2010)
Noori N,
Sims JJ,
Kopple JD,
Shah A,
Colman S,
Shinaberger CS,
Bross R,
Mehrotra R,
Kovesdy CP,
Kalantar-Zadeh K
Iranian Journal of Kidney Disease 4(2)
pp89-100, reports that "fresh (non-processed)
egg white (phosphorus-protein ratio less than 2 mg/g) is a good example of
desirable food, which contains a high proportion of essential amino acids
with low amounts of fat, cholesterol, and phosphorus."
Another human study,
Dietary egg whites for phosphorus control in maintenance haemodialysis
patients: a pilot study (2011)
Taylor LM, Kalantar-Zadeh K, Markewich T, Colman S, Benner D, Sim JJ &
Kovesdy CP Journal of Renal Care 37(1) pp16-24, and discussed
in
Renal and Urology News
(2008), found that egg
whites even helped lower phosphorus in patients who ate six cooked egg whites
in place of a meal each day.
Egg White
Cautions
Although egg whites are nutritious with
minimal waste production, they do not have many calories, so you do not want
them to make up too high a percentage of your cat's daily food intake.
One to two egg
whites each day might be appropriate, if your vet agrees, as long as your
cat also eats a complete cat food.
Eggs may inhibit iron absorption.
Prediction of dietary iron absorption: an algorithm
for calculating absorption and bioavailability of dietary iron
(2000) Hallber L& Hulthén L American Journal of Clinical Nutrition
71(5) pp1147-60 found that eating eggs reduced iron absorption by
around 27%. This applies more to the yolk than to the white but be careful if your cat is anaemic.
Egg White
Formulations
Egg whites are available either in the
old fashioned way (i.e. from a fresh egg), or in liquid form (also fresh) or
powdered versions. Some brands contain
onion,
which you should avoid.
If you buy
dried (powdered) egg whites, make sure they are pasteurised (they usually
are).
Since the cartons
contain quite a few egg whites, you may not use them up quickly enough, but
it should be fine to cook some of the leftover egg whites, then freeze them.
It is possible to freeze some liquid egg whites without cooking them first,
but check the brand's instructions. Some people freeze the egg whites in ice
cube trays so it is easy to take out just what they need.
Egg White
Preparation
It is important
to cook egg whites until they are hard, because uncooked egg white contains
something called avidin, which combines with biotin (one of the B-complex
vitamins) to make it unavailable, and CKD cats do need their B vitamins.
Cooking the egg whites destroys the avidin.
Therefore you need to
check whether the type you buy has already been cooked. Liquid ones
usually have not been cooked, but powdered ones may be cooked. Double check whether what
you has is cooked. Just because it is pasteurised doesn't mean it is cooked,
and pasteurisation alone is not sufficient to deactivate the avidin. If you have to cook
them yourself, make sure you do it thoroughly.
If you are using fresh or liquid egg
whites, you can scramble them and serve
them to your cat, or add cooked egg whites (chopped) to your cat's food.
Some cats will eat them when served in this way but many won't. Therefore
you may have to use a blender to make them fine enough to add to the food
without being off-putting to the cat.
If you are using powdered cooked egg
white, you can often just sprinkle it on your cat's food and mix it in. As a
rough guide, two teaspoons of powdered egg white are roughly equivalent to one egg
white, but check on the packet.
Egg White
Sources
In many countries you can buy cartons of
egg white, both fresh and dried, in supermarkets.
Egg White Sources: USA
Egg White Sources: UK
-
Two Chicks Free
Range Liquid Egg Whites are available from most UK
supermarkets, including Sainsbury's, Waitrose and Tesco. There are
fifteen free range egg whites in a
carton, which should be stored in the fridge.
I have used these with no problems.
Liquivite/Royal Canin Renal Liquid/EmerAid
Intensive Care HDN Kidney
There are several liquid supplements
available for cats, which
may be helpful if you are feeding your cat via a
syringe or a
feeding tube,
or if you want to get more calories into your cat. They could also be useful
if your cat is not eating normal cat food (e.g. if your cat is only eating
baby food) because some of them are nutritionally complete.
Liquivite is a canned liquid food made from chicken, liver,
beef and eggs, with a relatively low phosphorus content (0.75% on a dry
matter analysis (DMA) basis), though it does have a relatively high fat
content.
EmerAid Intensive Care HDN Kidney
is a "highly digestible nutrition" product which is available in 100g
or 400g pouches, that has a 30 day shelf life after opening. It
does state it is for intermittent or supplemental feeding only.
Hill's a/d Prescription Diet
Hill's a/d Urgent Care is a food specially formulated for
convalescent cats: it has high levels of liver, is very mushy and extremely
smelly. Quite frankly, the smell makes me feel ill; so
naturally, all my cats adore it. Once Thomas gave up on ham, we were
at our wits' end; but Hills a/d kept him going through his crisis and was a
real lifesaver. Because it is so mushy, it is very easy to use for
syringe feeding.
This food
is a therapeutic food which in theory is only available
from vets. It should not be fed to a CKD cat long-term because it contains
a lot of liver (too high in
vitamin A) and is high in phosphorus (1.16% on a DM
basis); but it is
excellent for short periods of crisis and/or convalescence. Hill's
a/d contains around 183 per can, or 33 calories per ounce.
Once opened, a can of Hill's a/d should be kept for a maximum of 36 hours.
Dairy
It is estimated that
around 80% of cats are lactose intolerant, which can cause diarrhoea and
vomiting. For this reason, it is usually recommended that cats are not fed
milk. If your cat is not lactose intolerant, it is usually safe to feed
milk, though it does contain protein and phosphorus, so is best kept as an
occasional treat. Full fat milk actually contains less phosphorus than
skimmed milk (though neither contains much phosphorus), and the
additional fat in full fat milk may be helpful for CKD cats who tend to
be thin.
If your cat is lactose intolerant,
there are special lactose-free milks available for cats, such as
Cat-Sip, which also
has added taurine.
Kattovit sells something in the UK and Europe that it calls Renal
Special Cream. These are little sachets of cream that each contain around
0.67% phosphorus.
Many cats seem to like
cream cheese. One of my cats got a little cream cheese every day for over
thirteen years (it started because she was abused before she came to us and frightened of men, so
my husband was trying to bribe her to like him) and it seemed to help with
hairballs. If your cat likes cream cheese, ask your vet about giving a
little to your cat occasionally.
Baby Foods
Baby
foods
can be helpful if you are trying to tempt your CKD
cat to eat in the short-term.
Aim to buy the simple meat-based foods rather than those
containing veggies and fruit.
Please
also ensure you purchase a food without any
onion, garlic or onion powder .
In principle baby foods sold in the USA have to list every single ingredient
on the jar, so if the ingredient is not listed, the food should not contain
it.
Hepatic lipidosis — managing and feeding
the anorectic cat (2016)
Scherk M Music City Veterinary Conference says "A cat eating small amounts
of baby food will not meet his caloric needs until he eats two – three
jars/day. Meat baby food is not balanced, but is sufficient for several
weeks."
Do not feed baby foods
exclusively long-term, because they have an
imbalanced phosphorus:calcium ratio.
Pet
Education
explains more about this. Plus, like other human foods, they lack
taurine,
an amino acid which cats need to obtain from their food.
A lack of taurine in a cat's diet can cause serious heart and eye
problems.
If you feed baby food
exclusively for longer than a few days, add 500mg of taurine to it, which is
not perfect but it will reduce the risks somewhat. However, it is OK to feed
a little baby food each day without taurine e.g. when giving pills, as long
as it is in addition to a more balanced (usually a commercial) cat food. Be
guided by your vet.
Wholesome Baby Food has some recipes for
making your own baby foods.
USA
You want the type of foods that are very smooth and meat-based only, without
vegetables or fillers such as pasta. Look for Gerbers 2nd Foods Meats,
Beech-Nut Stage 1, or Heinz Stage 2.
These foods are safe
at the time of writing, but formulations can change, so do check the
labels.
Here are the foods available in each range:
|
Available Varieties |
|
Brand |
Beef |
Chicken |
Turkey |
Ham |
Website |
Gerber 2nd Foods
Meats |
Beef and
Beef Gravy |
Chicken and Chicken Gravy |
Turkey and
Turkey Gravy |
Ham and
Ham Gravy |
www.gerber.com |
Beechnut Stage 1
Classics |
Beef and
Beef Broth |
Chicken and Chicken Broth |
Turkey and Turkey Broth |
|
www.beechnut.com |
Heinz Stage 2 |
Beef with
Beef Broth |
Chicken with Chicken Broth |
|
|
www.heinzbaby.com |
My cats liked the Gerbers 2nd Foods Meats range the best, especially the ham
flavour. These foods kept Indie going when she had largely lost her appetite
after extensive dental surgery. They are fairly runny and she was able to
lap them up with her tongue.
Although baby foods
are relatively
high in protein, they are low in phosphorus — they contain
about the same amount of phosphorus as a portion of therapeutic kidney food containing the same number
of calories. The ham variety is currently the lowest in
phosphorus and protein, and although people worry that ham baby food will be
high in sodium, it actually contains less sodium than virtually all
therapeutic kidney diets.
Here is some information about the levels of
phosphorus, protein, sodium and fat in a number of US baby foods. All foods of a particular flavour
tend to be similar in terms of
content. These figures are as at June
2020 so might be out of date (since I'm not in the USA, I find it virtually
impossible to access some websites, including Gerbers), though the
composition rarely changes so the nutrients probably don't either.
|
Phosphorus |
Protein |
Sodium |
Fat |
Carbs |
Calories per ounce |
Ham |
0.42 |
57.95 |
0.23 |
19.49 |
18.97 |
27 |
Chicken |
0.43 |
60.89 |
0.22 |
35.11 |
0.44 |
37 |
Beef |
0.53 |
68.51 |
0.23 |
14.35 |
13.84 |
23 |
Turkey |
0.59 |
58.43 |
0.25 |
31.50 |
7.11 |
31 |
Gerber's baby foods
are available in most supermarkets, though ham seems to be harder to find
lately (try Walmart). They are sometimes cheaper at Walmart or Wegmans. Heinz and Beech-Nut are also widely
available.
Amazon sells twelve jars of Gerber's.
UK
When I tried
using baby foods in the UK with Tanya, I
had great difficulty finding anything
suitable because most of the UK baby foods
seem to have large amounts of carbohydrate rather than the meat that cats
usually prefer and need. Fortunately Heinz have
introduced a food called Four Month Mum's Own in Beef Purée flavour
which appears to be suitable.
Ulula
sell baby foods online in the UK,
including the organic Holle brand which is water, pure meat and rice flour.
It is available in
beef
and
chicken varieties.
I have used Holle for my cats and they love them.
Meat or Fish Pastes (Potted Meat)
If you are in the UK
and are having difficulty getting hold of suitable baby foods, you could
consider using meat or fish pastes instead. I used these for Tanya, and they
were one of the few things she was prepared to eat.
I have found Marks and
Spencer Potted Salmon to be very popular with most of my cats but a beef
flavour is also available if required, though check the ingredients list for
onion or garlic (the Salmon version does not contain either). These products
are very smooth, so are easy to get your cat to lick off your finger if
necessary. I haven't tried to syringe them but imagine they would be
suitable if watered down.
If you are outside the
UK, supermarkets in many other countries also sell potted meats.
Human Food
This is certainly not the best food for a
CKD cat, but if your cat is recovering from a crisis or being extremely
pernickety, you may have to resort to offering tasty human foods to tempt
your cat back into eating.
Chicken or lightly cooked fish are possibilities. If
you're in the UK, you can also go to the chippy — my cats will almost always
eat fish from the chippy (with the batter removed).
When Thomas's anaemia was at its worst, he would only eat ham for two weeks. Even though the levels of sodium and
nitrates in the ham were very unhealthy, eating ham was better than
not eating anything at all (though I think other options on this page would
be a better choice).
Many commercially sold chickens have a
lot of salt too.
Do not feed these sorts of foods
long-term, because they lack the nutrients that a cat needs, particularly
taurine,
an amino acid which cats cannot manufacture themselves, and a lack of which
can cause heart and eye problems; but in order to kick-start eating, they
can be helpful. Please do not feed your cat
anything containing onion or garlic and be careful about feeding tuna (see
Which Foods
to Feed).
Nutri-Cal
You may be offered a high calorie
supplement called
N\utri-Cal,
which comes in a tube and is stocked by many vets. It
is not my first choice because it is relatively high in carbohydrates rather
than protein and has some additives. However,
it
does help tempt some cats to eat, so it might be of help during a
crisis, though some of the other choices on this page are probably better.
Nutri-Cal appears to contain a relatively high amount of Vitamin A,
so do check with your vet before using this, because too much
vitamin A is not good for CKD cats.
Fancy Feast (Gourmet Gold)
Fancy
Feast often seems to be considered to be a
"bad" food. I've never quite worked out why this
is, but I get the impression Fancy Feast is considered to be akin to "junk
food" that is full of by-products. That's what some
humans seem to think anyway. Most cats, however, love Fancy Feast, to such
an extent that in some circles (my house) it is known as "kitty crack."
Many Fancy Feast flavours are not
particularly complicated foods. In fact, many of them have broth as the first ingredient
rather than the more commonly seen water. Not only that, but, because many flavours do
not contain added gluten, Fancy Feast was not affected by the 2007 pet food
recalls, unlike many so-called premium brands.
From a CKD perspective,
sadly
no Fancy
Feast flavour has a phosphorus level below 1%. This is higher than you
ideally want, but may be worth considering if your cat simply won't eat
anything else. The pâté-style foods (labelled Classic) tend to have higher
levels of phosphorus, getting closer to 2%, which is far too high for a CKD
cat. The marinated and grilled flavours tend to have
high sodium levels, so would probably not be a good choice for cats with high blood
pressure. The Appetizers are not complete foods, so should not be fed
exclusively. You can check the
food data tables
for more information on the levels of phosphorus and sodium in
some of the
Fancy Feast varieties.
I'm not claiming that Fancy Feast is
perfect. Some flavours
contain a preservative called sodium nitrate (or nitrite).
Nitrite poisoning in cats and dogs fed a
commercial pet food
(1997)
Worth AJ, Ainsworth SJ, Brocklehurst PJ & Collett MG New Zealand
Veterinary Journal 45(5) pp193-195 reports on the effects of this
preservative on some cats (note: there is no evidence that the food used in
this study was Fancy Feast).
But
basically, most cats do seem to love
Fancy Feast, and even those who are not feeling
too good may eat Fancy Feast. Some cats on
Tanya's Feline CKD Support Group
have eaten
nothing but Fancy Feast for years, and have done well on it, with the
addition of phosphorus binders when needed (i.e. if their
blood tests show phosphorus levels that are too high).
The pâté-style foods (labelled Classic), whilst too high
in phosphorus to use as a regular diet for CKD cats, are often easier for
cats with poor teeth to eat than the other types (grilled, marinated etc.),
and can also be mixed with water until smooth and used for syringe feeding
or as a base for mixing medications.
Therefore if you live in the USA, I would
recommend
at the very least keeping a few
cans in the cupboard in case of need. It was the only thing Indie
would eat when she was sick once.
The nearest UK version
of Fancy Feast, judging by the tins,
seems to be Purina Gourmet Gold.
Unfortunately it does not appear to have the same "kitty crack" appeal of
Fancy Feast, plus it seems to have much higher levels of phosphorus.
However, it may be useful to try this in times of crisis.
Tempting Your Cat to Eat
Since CKD cats often have poor
appetites, this section has tips on how to encourage your cat to eat. Some
of these methods take seconds, so they are definitely worth a try.
If you can persuade your cat to eat of
his/her own accord, it is usually much less stressful for both of you.
Also check out the previous section
on
additional nourishment, because some of the
suggestions there may help.
Raising the Food Bowl
Do this first. It takes seconds and really works for
some cats. Just use a thick book or a flower pot, or you can buy proper
raised food bowls if you wish. I have raised food bowls for my cats, who are
healthy, but I noticed they started to eat more once they were given raised
food bowls.
For more information on why this can be helpful, how
to create temporary bowls and where you can buy proper raised bowls, see
Appetite Loss, Nausea and Vomiting.
Feeding Location
Where you serve food
can make a difference. If your cat is weak, don't place the food bowl miles
away from his/her favourite resting place. Novelty may also help: I used to
feed my cats in the kitchen but once one of them became ill and needed a lot
of encouragement to eat, I had food bowls all over the place. The place
looked a bit like a kitty restaurant, but I didn't care.
I also have found that
a cat may refuse to eat a plateful of food in one room but will eat that
self same plateful of food in another room.
If you have younger, pushier cats,
it can help to feed your CKD cat separately; your sick cat will be able to
eat at his or her chosen pace, and may want to eat more.
Many people find having a plateful
of dry food out on their bedside table can encourage their cat to eat during
the night.
How to encourage senior cats to eat
(2012) Little S is a video which gives tips on persuading older cats to
eat. It mentions that feeding an older cat away from other family cats can
be helpful.
The feeding behavior of the cat
(2010) Horwitz D, Soulard Y & Junien-Castagna A Encyclopaedia of Feline
Nutrition pp439-477 mentions
(on page 8) that in food tasting
trials, manufacturers have discovered that many cats have a definite
preference for the side their food is on, and will eat from that bowl
regardless of food choices available. This is worth experimenting with if
you place the food bowl in such a way that your cat can only approach it in
one way. Move it to the left or the right and see what happens.
Food Presentation and Storage
How you store and serve food
can make a difference to some cats. My pampered felines like
their food as fresh as possible, so I only buy small size packets
because they become quite disdainful as we get towards the end if I try
to serve larger cans.
If you use canned food, be sure to store any leftover food
in glass containers in the fridge rather than in the cans themselves.
The University of Warwick
has more information about why this is a good idea.
Cornell University College of Veterinary Medicine
also has some information about food storage.
Consider using flat plates to serve
food. It is thought that cats do not like their sensitive whiskers to
touch the bowl while they are eating, and whilst healthy cats may not
mind this so much according to
Evaulation of whisker stress in cats
(2020) Slovak JE & Foster TE Journal of Feline Medicine and Surgery
23(4) pp389-392,
the study did also find that some of the cats did prefer the
whisker-friendly bowl. Therefore I think it is worth trying flat bowls to see if this helps,
particularly if you have Persians, as I do.
It can also be helpful to avoid washing cat bowls
with any type of soap and detergent, but simply to use very hot water
instead.
Warming Food
Many cats, including mine, do not like
food
straight from the refrigerator — it seems to be
too cold for them. Try taking the food out of the fridge half an hour before
feeding it.
International Cat Care
mentions that cats tend to prefer food at a temperature of around 35° C,
which happens to be the same temperature as freshly killed prey.
You may wish
to try actually warming your cat's food.
Aging cats prefer warm food (2022) Eyre R, Trehiou M, Marshall E, Carvell-Miller
L, Goyon A & McGrane S Journal of Veterinary Behavior 47
pp86-92 found that older cats (aged over 7!) preferred eating food with a
temperature of around 37ºCelsius. The study states "Warmed wet food can help
to promote food consumption in aging cats, especially those that have lost
interest in eating or do not consume enough product to maintain a healthy
body weight."
This could be even more important for CKD cats.
The
sense of smell (and sometimes of taste) in human kidney disease patients is impaired. Smell and taste function in children with chronic
kidney disease (2010)
Armstrong JE, Laing DG, Wilkes FJ & Kainer G Journal of Pediatric
Nephrology 25(8) pp1497-504 found that this can occur early on in
CKD in children, and that it tends to worsen as the disease progresses,
and it is thought that this happens to
CKD cats too. Warming the food makes it smell stronger, which may filter
through to the cat and encourage him/her to eat.
We microwave the food on a plate for about 4-5 seconds on High, but your
oven may vary. If you use the microwave, stir
it thoroughly afterwards and make sure it is not too hot — food cooked
in the microwave may cook unevenly and contain "hot spots" which could burn
your cat if you are not careful.
We have also tried warming the
food by adding hot water — again, be sure it is not too hot. Some cats
prefer the mushy texture of food that is watered down.
Sleepy Eating
Several members of
Tanya's CKD Support Group have found that they stand
more chance of getting their cat to eat if they wave a plate of food under
the cat's nose as soon as s/he wakes up from a deep sleep. It's as if the
cat is on automatic pilot and eats instinctively.
Food Texture
Some people have found
that cats who are off their food seem to prefer pâté-type foods to more
lumpy foods. If you offer more solid foods, you will often find that your
cat merely licks off the gravy. You can either buy pâté-type foods (many of
Hill's pâté-style foods are low in phosphorus), or you
can use a liquidiser or blender (or a fork, if you don't have a blender) to
make any food smoother.
A popular choice
in the USA is the Magic Bullet, which costs around US$40-50.
Amazon
sells another
blender, the Elite Gourmet, for around US$10. In the UK,
Amazon sells the
Kenwood CH180 mini chopper for around £25.
Depending upon what
you are feeding, you may be able to blend larger quantities and freeze some
of the portions.
Some people have had
success by squashing small portions of canned food into little balls and
feeding them to their cats by hand (see
below).
Pretend to Eat It Yourself
I have found that if I pretend to eat my
cats' food, this can encourage them to eat it themselves. Don't forget the
loud appreciative noises! I haven't yet gone as far as actually eating their
food, but give me time...
Some people also find that offering a
food to another feline family member may tempt the sick cat to eat the food,
especially if you make it look as if you are trying to give the other cat a
secret treat.
Broth/Puréed Food
Some people have found homemade
chicken broth very helpful for their CKD cats. Just
boil the whole chicken (including skin and bones) in water, there is no need to add any
vegetables, definitely not
onions,
and never give chicken bones to your cat. Chicken broth made in this way is not high in calories but
it can help
make foods more appetising and also increase fluid intake. You can either add
it to food
(particularly therapeutic diets) or simply give it
to your cat to drink. Some people freeze it in cubes.
When buying chicken to make the
broth, make sure that it does not contain added broth, which may contain
sodium
and onion.
Many commercially sold chickens
have a lot of salt,
You can check how much sodium is in
a chicken by looking for sodium in the nutritional information on the
packaging: anything over 100mg of sodium means that sodium has been added.
Some people have tried a simpler
approach and simply add lots of water to their cat's canned food in order to
make it soupy. You can use a blender if necessary to make it fairly smooth.
Cats with mouth ulcers in particular may prefer food with this texture.
If you're not culinary-minded,
commercially produced broths are now available.
Fancy
Feast broths that many cats seem to like are available in
the USA and some of them are pretty low in phosphorus, though the data are
as at 2020, so this may have changed:
Fancy Feast
Broths |
%
Phosphorus (DMA) |
Chicken & Vegetables in a Decadent Creamy Broth |
0.77 |
Chicken &
Vegetables in a Decadent Silky Broth |
0.80 |
Chicken, Vegetables
& Whitefish in a Decadent Silky Broth |
0.82 |
In the UK and Europe
Kattovit Renal Drink is a possibility. I've heard
from several people who find adding a little to their cat's food encourages
them to eat. Unfortunately I don't know the phosphorus content, but since it
is marketed as a renal drink, I presume the phosphorus level will not be
massively high.
Please check the phosphorus content with
the brand in question before feeding any of the above mentioned broths because levels may well have
changed.
Feeding Little and Often
Many CKD cats no longer routinely ask for
food, or not frequently enough to maintain their weight,
so they need your help. Try to offer your cat small amounts of fresh
food at regular intervals, if necessary taking the food direct to your cat.
We used to have a rule that cats eat in the kitchen but that soon went out
the window once we were faced with a sick cat. Just
offer a spoonful at a time. If your cat eats it, offer a little more.
If you do
have the time to offer food frequently, you can find that although your cat
only eats a little each time, over the course of a day it can add up to a
reasonable food intake. You may also find that this reduces the build up of
gastric hyperacidity in your cat.
If you are out at work all day, you could
try using a timed automated feeder which opens separate compartments at
times of your choosing so that your cat can have access to fresh canned
food. These are also useful at night. See
Which Foods to Feed for links to feeders.
Kitty Smorgasbord
Until your cat is
stable, you may have to resign yourself to having a "kitty smorgasbord"
available for a while. This means you have a selection of foods for your cat
to choose from, which you rotate to suit your cat's current preferences.
When Harpsie (non-CKD but he had a severe kidney infection) was sick and off
his food, we ended up with eighteen different foods on offer. We had to
build a shelf just to hold them all!
Obviously we didn't offer all these foods
in one go!
We would offer him one
food and if he wouldn't eat it, we would try another. We found he might eat
one of the foods one day, then refuse it the next. Sometimes we would offer
him five or six foods before we found one he would eat. Then a week or so
later, a food he had previously turned down might be back in favour.
We also found
that he might refuse a food in the kitchen but be prepared to eat the same
plateful of food in the lounge. Or he might eat the food if we moved it back
into the middle of the plate. The plate mattered too: he seemed not to like
plastic plates but preferred china (well, he was an English gentleman...).
Flat plates were also important (see
above).
You can also mix
foods, e.g. put a little baby food or a tasty extra on top of the
food you really want your cat to eat.
Tempting
Extras and Treats
These are items which
you can sprinkle on your cat's food in order to make it more tempting for
your cat. I have had good luck with Salmon Liv-a-Littles in particular.
Fishy Extras
Fish can be a bit of an issue for cats
(see
Which Foods to Feed),
but a little sprinkled on the food occasionally to tempt your cat to eat is
probably OK.
-
In the UK
Zooplus sells the
Cosma brand of freeze-dried treats. They are available in tuna, chicken, duck
and
beef varieties, and you can also buy a mixed taster pack to see
which your cat prefers.
Meaty Extras
Although these tend to be pure meat and are therefore
relatively high in protein and phosphorus, you use so little when you
sprinkle them on food that it should not be a problem.
-
Lick-e-Lix in the UK is a product with a
baby food type texture. My cats absolutely love these. Apparently the phosphorus level
is around 1.1%.
Amazon UK sells Lick-e-Lix in salmon flavour.
-
Zooplus in Europe
and the UK sells the
Cosma brand of freeze-dried treats. They are available in chicken, duck,
beef and tuna varieties, and you can also buy a mixed taster pack to see
which your cat prefers.
-
Some people on Tanya's Support Group like
to add a little goose fat or duck fat to their cat's food, both to make the
food more palatable and to increase their cat's calorie intake. In the UK
many people roast their potatoes in these fats, so you can find them in
supermarkets, usually near the bottled oils. In the USA you may be able to
find these fats in the gourmet section of your supermarket. Wholefoods sells
the Epic cage free duck fat brand, which is also available from Amazon.
Catnip
I am sometimes asked if it is acceptable
to give catnip to a CKD cat. It is fine, and in fact may act as an appetite
stimulant in some cats. However, not all cats react to catnip — this is a
genetic trait.
Cats International
has some information on catnip.
Tuna Water
Whilst tuna itself is not
appropriate for cats (see
Which Foods to Feed),
one possible compromise is to add the water in which tuna is packed to your
cat's therapeutic kidney or other diet in order to moisten it and make it more
palatable. Tuna packed in water may actually be packed in a type of broth,
which may contain
onions;
and some brands may contain high levels of
sodium,
so you need to be very sure the brand you use is acceptable.
Starkist Albacore White Tuna low Sodium
(pouch) seems to contain only tuna and water.
Amazon sells Crown Prince tuna in water
with no added salt.
Trader Joe's sell
their own brand Low Sodium Tuna packed in water, and other chains may do the
same.
Acupuncture
When my cat, Harpsie, began having
acupuncture (for his arthritis), there was a noticeable improvement in his
appetite. I don't know if this was a direct result of the acupuncture
itself, or whether being in less pain from the arthritis made him feel
better generally; but I know of
several CKD cats who receive acupuncture solely
for appetite stimulation, and it seems to work for them.
Holistic Treatments has more information on
acupuncture.
Assisted Feeding
You will probably have times when
your cat refuses to eat. Naturally, you must try to address all possible
causes of inappetence, such as gastric hyperacidity, mouth ulcers and nausea (see
Index of
Symptoms and Treatments), and the suggestions
above to make the food seem more appetising. But if all else fails, there
are a few other things you can try.
Company While Eating
We found this helpful with both Tanya and
Thomas. We would sit by them encouraging them to eat, praising each
mouthful. It does work for some cats. If Harpsie was lying near us on the
sofa, we also used to place a plate of food nearby, also on the sofa, so he
did not have to move far to eat.
We also found that if we pretended to eat
a food, the cats
would try it too. See above
for more on this.
Feel free to be inventive. I remember
hearing from one lady some years ago who was trying in vain to get her cat
to eat. She failed, and lay down on the floor feeling miserable. Her cat
promptly climbed on her stomach and lay there, so she gently reached for the
food bowl and placed it on her torso. Her cat ate! From then on, she found
she could always get her cat to eat of his own accord if she did this. It
didn't require much effort on her part, in fact it gave her a chance to
relax, happy in the knowledge that her cat was eating, so it was a win win
situation.
Feeding by Hand
This
is the next stage, where you lift the food out of the bowl and encourage
your cat to lick it off your finger or a spoon. It can take hours, and
your cat will probably drop lots of the food, but we found this really
helped persuade both Tanya and Thomas to eat.
This also helped with Lily
(above), our kitten with FIP.
We microwaved some white fish (cod) on high for about five minutes (your
microwave might vary) and then fed her the cooked flakes by hand.
Some people have had
success by squashing small portions of canned food into little balls and
feeding them to their cats by hand.
Syringe (Assisted) Feeding
Finally, you can try what some
people call force feeding, but what I prefer to call assisted
feeding. This entails placing your cat's food into a syringe and syringing
it
gently into the cat's mouth.
Hill's a/d
in particular can be made into a mush with water and syringed in easily.
Alternatively, you can use a pâté-type food such as
Fancy Feast
(Gourmet
Gold in the UK) or some other canned food and purée it
using a mixer or blender.
However,
do not assist feed a food you would like your cat to eat
in the future, because some cats may develop an aversion to a food they eat
while they are sick.
Add water to make the food more liquidy if it is too hard to squeeze out of the syringe, then draw it up into a syringe.
You don't usually need too much water, add a little and see how it is; you
can always add more if necessary.
Using warm water can make the food more attractive to
your cat. If necessary, use a strainer to make the food smoother,
Amazon sell
one.
If you
assist feed, you may as well aim to feed a reasonable amount of food to your
cat, bearing in mind your cat's
calorie needs,
though you will probably
want to start with smaller amounts until you and your cat get used to
the process,
especially if s/he has not been eating much recently.
How
much to give depends upon how much weight your cat has lost, and how many
calories the food contains. You can tell if you are feeding enough if your
cat’s weight stays the same or (if your cat is too thin) gains weight.
However, just as a cat doesn't eat a day's worth of food in one meal, so you
don't need to assist feed in one big session; if you can, spread the food
over several smaller sessions a day. I used 10ml syringes and would only
give one syringe full at a time, but doing this every 2-3 hours added up to
a reasonable amount of food. If you're out at work for most of the day, you
will have to give more at one time, but to make things easier, you can make
up several syringes at a time and store them in the fridge before use. If
you work, you should still be able to feed three times a
day (before work, after work and before bed). Yes, it is a commitment, but
in some ways it is less time-consuming than following your cat around with
platefuls of food.
It is also important to assist feed properly:
hold your cat upright,
make sure the food is reasonably mushy so it flows
smoothly, go slowly, try to stay calm. Insert the syringe in the side
of the mouth, not directly in the front, so as to reduce the risk of the
food going down the wrong way; and give your cat time to swallow each
mouthful. You must also only
syringe in a little food at a time and give your cat time to swallow it. All
this is in order to avoid the risk of aspiration pneumonia.
Pet Place has more
information on this,
as does
Cornell University College of Veterinary Medicine.
Don't worry if your
first session doesn't go too well, you and your cat both need time to get
used to this new routine. You will probably both be a bit messy, so wear old
clothes, cover your furnishings with a throw and have a damp cloth close at
hand to wipe your cat. Some people find it easier to wrap their cat in a
towel. It may be more comfortable for your cat if you
warm the food but be careful not to have it too hot, you don't want to burn
your cat's mouth.
You can feel
really mean when you
assist feed, and it doesn't help that some vets claim
that if a cat stops eating, it's time to let go. All I can say is, I'm glad
that doesn't apply to humans too because I would have been dead years ago if
so! I saw in the new millennium with a nice bout of flu during which I was
unable to eat a thing.
We had to assist feed Tanya
occasionally at our vet's suggestion; luckily it was usually only necessary
for a day or two, although some people on
Tanya's CKD Support Group
do this on an ongoing basis.
If you are doing this on an ongoing basis, I would feed a
therapeutic kidney diet. However, don't assist feed a food you
would like your cat to eat in the future, because some cats may develop an
aversion to a food they eat while they are sick.
Tanya was a very independent cat, but
she coped far better with
assist
feeding than we would have expected, and your cat
might be the same.
Assist feeding can actually reduce
stress for both of you. You know your cat
has eaten enough rather than watching anxiously and trying to ascertain if
his/her food intake has been sufficient that day.
Your cat is not being hassled by you waving twenty
different foods under his/her nose. Plus you will also save money by
not having to throw away twenty different rejected foods each day.
Kathy assist feeds Toady is a helpful video
on how to assist feed a CKD cat.
Syringe feeding Coco is a good, clear video showing Marga feeding
Coco (this is in Dutch but you will be able to see what Marga is doing).
Syringe feeding Jasper
is a video from Roni. When Roni first began
assist feeding, she could barely get
three squirts in but here, three months later, you will see she can easily
feed a decent amount of food.
Holisticat
has detailed instructions on how to assist feed.
Choosing a Syringe
The size syringe you should choose
depends upon how strong your hands are — the smaller and weaker your hands
are, the harder it is to push a larger syringe. I have small hands and found
a 10ml one worked best for me with Tanya. Some people prefer smaller ones,
such as 3ml or 5 ml.
Syringe Sources
Some pharmacies in the USA will give you
syringes for free if you ask.
Lambert Vet Supply
in the USA sells Baxter syringes with an "O-ring",
though they are currently (June 2025) out of stock. O-ring syringes last longer and some people find
them easier to push than standard
syringes.
Innovet makes soft tipped syringes which
many members of my support group like.
The Squirrel Store
sells O-ring syringes.
Amazon
sells packs of two Easy Feeder syringes, one of which is
for giving water, the other is good for assist feeding.
Pets at Home
in the UK sells Mikki hand
feeder syringes.
Feeding Tubes
If all else fails, your vet may suggest a
feeding tube. This is a device that is implanted into your cat and you then
simply pour food and medications into it.
When to Use Feeding Tubes
These tubes can last for up to a
year, but are normally only used until the cat is eating enough to maintain
his/her weight. Most people seem to leave the tube in until the cat has been
eating enough unaided to maintain his or her weight for at least two weeks.
You should monitor your cat's weight closely
(you can find sources for suitable scales
here).
Some vets are opposed to feeding tubes
for CKD cats, believing that if a cat reaches this stage, it is cruel to
keep them alive. This used to be particularly the case in the UK, but this
is changing.
Utilization of feeding tubes in the management of chronic kidney disease
(2016) Ross S Veterinary Clinics of North America
Small Animal Practice 46(6) pp1099-1114 says "E-tubes are useful,
and in many cases essential, for the comprehensive management of cats with
moderate to advanced CKD."
Studies indicate that feeding tubes can
be very helpful and most cats do not seem to find them distressing.
Use of feeding tubes in 112 cats in an internal medicine referral service
(2015-2020) (2022) Brunet A, Bouzouraa T, Cadore JL & Huggonard M
Journal of Feline Medicine and Surgery 14(10) ppe338-e446 found
that "feeding tubes are generally well tolerated with only minor
complications and can help recovery from a variety of illnesses." The usual
complication was actually the cat removing the tube.
IRIS treatment recommendations for CKD in
cats
(2023)
International Renal Interest Society
states that they should be considered for Stage 4 cats: "Intensify efforts
to prevent protein/calorie malnutrition. Consider feeding tube intervention
(e.g., percutaneous gastrostomy tube)."
2022 Consensus guidelines on management of the
inappetent hospitalised cat (2022) Taylor S, Chan DL, Villaverde
C, Ryan L, Peron F, Quimby J, O’Brien C & Chalhoub S Journal of Feline
Medicine and Surgery 24 pp614-640 go further, stating "Postponing
interventions such as feeding tube placement to await improvement, owing to
clinician or caregiver apprehension, may hinder recovery and worsen
nutritional deficits."
ISFM consensus guidelines on the diagnosis and
management of feline chronic kidney disease (2016)
Sparkes AH, Caney S, Chalhoub S, Elliott J, Finch N, Gajanayake I,
Langston C, Lefebvre H, White J & Quimby J Journal of Feline Medicine
and
Surgery 18 pp219-239 do not specify in which stage CKD cats
should receive feeding tubes, merely saying
"if cats remain too nauseous or unwell to
maintain sufficient voluntary food intake despite appropriate treatment,
placement of an enteral feeding tube (eg, oesophagostomy or gastrostomy)
should be considered, and anecdotal reports suggest these can be valuable in
maintaining food and fluid intake in some cats with CKD."
The kidney patient: what's for dinner?
(2010) Francey T Presentation to the
World Small Animal Veterinary Association World Congress states
"The initial reluctance of most owners to accept feeding
tubes that they view as artificial life support, is often overcome when
truly exposed to them. Esophagostomy tubes or PEG tubes are commonly used
for other indications and they can also markedly improve the quality of life
of small animals with advanced CKD. Administration of water in sufficient
amounts to help maintaining optimal hydration, ease and reliability of
administration of medications, and administration of the qualitatively ideal
food in sufficient quantity are the main benefits of feeding tubes. The use
of this type of nutritional support is the only way to push the limits of
the medical management of small animals with CKD without compromising their
quality of life."
I would say the vast majority of
Tanya's CKD Support Group
members who have tried feeding tubes have had good results, even for cats with less advanced
CKD. Feeding tubes may also be helpful for cats with
pancreatitis.
Feeding Tube Types
There are three main types of feeding
tube
VCA Hospitals
discusses the different types of tube.
2022 Consensus guidelines on management of the
inappetent hospitalised cat (2022) Taylor S, Chan DL, Villaverde
C, Ryan L, Peron F, Quimby J, O’Brien C & Chalhoub S Journal of Feline
Medicine and Surgery 24(7) pp614-640 discuss the pros and cons of
the different types of tube.
Oesophageal Tube (E-tube)
The oesophageal tube, which can normally be inserted with sedation only, is
inserted at the neck and runs down to the oesophagus. Usually food fed
through such a tube must be blended. Your vet can tell
you how much and how often to feed, though to start with you will usually
have to feed small amounts each time, gradually increasing the amount you
give.
These tubes can be
left in for months if necessary.
The University of Missouri Veterinary
Health Center
explains more about oesophageal tubes.
Esophagostomy feeding tubes
(2014) Hodshon B & Tobias KM Clinician's Brief Feb 14 pp66-72
discusses these tubes.
Kitty Kollar sells special collars to use with oesophageal
feeding tubes.
Gastrostomy Tube (PEG Tube)
The gastrostomy tube (sometimes called a
PEG tube) is placed directly through the cat’s side into the stomach. It
normally has to be inserted using a
general anaesthetic. This tube is less
likely to interfere with the cat’s swallowing mechanism than the oesophageal
tube, but neither type seems to bother cats particularly.
This tube can also be left in for months.
After the tube is
fitted, x-rays should be taken to ensure the tube is in the correct
position.
Percutaneous placement of a gastrostomy tube
(2009) Armstrong PJ DVM360 explains more about PEG tubes.
PEG tube feeding instructions
Stafford D Veterinary Support Personnel Network
explains how to feed your cat using a PEG tube.
Nasogastric or Naso-oesophageal Tube
Occasionally vets use a nasogastric
tube, which can be inserted without anaesthesia. This tube is placed in the
nose and runs down to the stomach. Unfortunately, these tubes are narrow so
can only be used for liquids, plus they are really only suitable for
short-term feeding of around five days.
If your cat is given
such a tube, the throat can be a little sore for a few days after removal,
so you will need to continue to feed smooth, easily swallowed food during
this period.
Feeding Tubes Tips
As with assist feeding,
you need to feed a decent amount of food, spread over a number of sessions
each day.
To prepare the food for the tube, you
normally need to blend it with a little water so it does not block the tube.
This means you often need to use a
strainer.
Amazon
sells
one. Some people also sieve the food after blending it.
You often use a syringe to place food in
the tube, see above
for more information on the best syringes to buy and sources.
Try not to syringe too much food into the
tube at once, but start slowly and build up gradually.
After feeding you should flush the tube
with about a teaspoon of water to clean it.
You will also need to check the
tube every few days to make sure it is not blocked and give it a more
thorough cleaning with equipment supplied by your vet.
One advantage of a feeding tube is that
you can give water (not the fluids usually used for sub-Qs) orally rather
than having to give sub-Qs.
IRIS treatment recommendations for CKD in
cats
(2023)
International Renal Interest Society
states that they should be considered for Stage 4 cats: "Feeding tubes can
be used to administer fluids as well as food." You can also give oral
medications via the tube.
Conservative medical management of chronic renal
failure in the cat (2010) DiBartola
SP CVC in San Diego Proceedings states "The
clinician should consider placement of a gastrostomy tube in CRF cats with
poor appetites because this approach allows convenient delivery of calories,
fluids, and medications and the tubes are well tolerated by most cats."
Feeding Tube Links
Tufts University College of Veterinary Medicine
has some helpful FAQs about feeding tubes.
Long
Beach Animal Hospital has more
information on feeding tubes.
Enteral nutrition: tube feeding
(2014) Wara
A & Datz C Clinician's Brief Nov 14 pp25-27 discusses feeding
tubes.
Enteral feeding in dogs and cats:
indications, principles and techniques (2010)
Mitchell KD CVC in Kansas City Proceedings
explains more about feeding tubes.
All Feline Hospital
explains how to use and care for feeding tubes.
Feeding tube placement
(1999) Seim HB
Presentation to the Waltham Feline Medicine Symposium discusses the pros
and cons of the different types of feeding tube.
Exclusively Cats Veterinary Hospital
explains more about feeding tube use and maintenance.
Feline Assisted Feeding Group
is not very active but may be worth joining if you have a
cat with a
feeding tube.
Appetite Stimulants
Since it is important that cats eat
regularly because of the risk of
hepatic
lipidosis (see above),
vets may sometimes prescribe a medication to stimulate appetite.
However, you should not
reach for these alone, because whilst some cats
may eat because of these medications, they could still
feel
horrible; and some cats who have untreated nausea
or vomiting will not eat even if given appetite stimulants.
Appetite stimulants
often do not work on cats who have completely stopped eating; they tend to
be more effective at persuading a cat who is still eating, but not enough,
to eat more.
Appetite stimulants may also have
side effects. Therefore you should definitely try
to treat any possible causes of inappetence (see
Index of
Symptoms and Treatments, scroll down to Appetite
Loss),
particularly
gastric
hyperacidity,
and try the other tips mentioned
above, rather than reaching immediately for appetite
stimulants.
Top five indications for appetite stimulation
(2020) Cook AK
Clinician's Brief Jun 2020 pp31-35 discusses when to consider
using appetite stimulants.
These days you are quite likely to be
given mirtazapine in the form of Mirataz but some vets may recommend
some of the other treatments discussed below.
B Vitamins
All CKD cats
should be given B vitamins, because they can help prevent anaemia and often
act as a mild appetite stimulant.
Pharmacological appetite stimulation: rational choices
in the inappetent cat (2014)
Agnew W & Korman R Journal of Feline Medicine and Surgery 16(9)
pp749-56 says "Cats have a higher requirement for some B vitamins when
compared with dogs. Experimental depletion of B vitamins results in
anorexia in other species. Supplementation with B vitamins may prevent
this occurring, although no evidence exists to confirm this. Still,
provision of B vitamins is simple and should be considered in all inappetent
cats."
Vitamin B12 in the form of methylcobalamin
can be particularly helpful. You can read more about B vitamins
here.
Mirtazapine (Mirataz, Remeron or Istin)
In recent years mirtazapine (Remeron
in the USA, Zispin in the UK, or Mirataz in either) has become
increasingly popular as an appetite stimulant for CKD cats. Mirtazapine
is actually an anti-depressant but in small doses it can
cause an increase in appetite. It does this via its effects on
serotonin receptors, which increase the level of serotonin in the brain and
lead to increased appetite. It may also have anti-emetic
(anti-vomiting) properties through its effects on serotonin receptors
in the gastrointestinal tract.
I haven't used mirtazapine for my own cats, but a transdermal version for
cats called Mirataz is now approved for use in the USA and Europe, so you
may well be offered it. Many people do find mirtazapine helpful and there has
been quite a lot of research
into its use in cats, including CKD cats, with it being widely used in vet schools.
Mirtazapine must nevertheless be used with caution in
those with kidney problems. It
should also be used with caution in cats with
hyperthyroidism or liver
problems.
The main concern with
mirtazapine is the small risk of developing a condition called
serotonin syndrome.
Please be sure to start with a small dose
and low frequency (see below) and monitor blood pressure.
Veterinary Partner has
information about the use of mirtazapine in cats. It mentions that it may
help with nausea as well as appetite.
Medicine Net has
information about the use of mirtazapine in humans.
Mirtazapine and Weight Gain
Mirtazapine
seems to be an effective appetite stimulant in cats, and
may assist with weight gain. Indeed,
Mirataz, the transdermal version of mirtazapine approved for
use in cats, describes itself as a weight gain medication rather than as an
appetite stimulant.
Mirtazapine as an appetite stimulant and anti-emetic
in cats with chronic kidney disease: a masked placebo-controlled crossover
clinical trial
(2013) Quimby JM & Lunn KF Veterinary Journal
197(3) pp651-655 found that "the
oral administration of 1.88 mg [⅛
of a 15mg tablet]
of mirtazapine every other
day for 3 weeks to cats with CKD resulted in significantly increased
appetite. Additionally, significant weight gain, increased activity and
decreased vomiting were demonstrated."
Double-blind placebo-controlled randomized study of
transdermal mirtazapine ointment for the management of feline weight loss
(2017) Longpre K, Buhles W, Tin M, Hu T,
Quimby J, Labelle D, O’Banion MP, Lee J & Markey S Journal of Veterinary Internal
Medicine (2017 ACVIM Forum Research Abstract Program) 31(4)
p1334 looked at the effects of transdermal mirtazapine on weight and found
that "Use of 2% MZP resulted in a mean weight gain of 4.07% compared to
0.29% for placebo after two weeks of transdermal treatment."
A double-blind, placebo-controlled, randomized study
to evaluate the weight gain drug, mirtazapine transdermal ointment, in cats
with unintended weight loss
(2019) Poole M, Quimby JM, Hu T, Labelle D & Buhles W
Journal of Veterinary Pharmacology and Therapeutics 42(2)
pp179-188 looked at the use of 2.mg transdermal mirtazapine in cats who had
experienced weight loss. The study concludes "Application
of mirtazapine transdermal ointment was well tolerated both topically and
systemically and resulted in significant weight gain in cats experiencing
unintended weight loss associated with various underlying diseases."
Mirtazapine Formulations and
Availability
Mirtazapine is available as tablets and in
some countries in transdermal
form:
Mirtazapine Tablets
Mirtazapine is widely
available in
15 mg tablet form, and many people have used
these, cut into the appropriate size (in most cases, people give ⅛ of a
tablet, but see below).
In the USA you should also be able to
find 7.5mg tablets at pharmacies such as Costco. They are also available
from
VetRXDirect.
At one point 2 mg tablets were available
in several countries (including Canada and the UK) for use in cats, though
these seem to have largely disappeared.
Mirtazapine Transdermal
There has been some research in recent
years into the use of transdermal mirtazapine in cats and a commercial
cat-sized version called
Mirataz was approved by the FDA in 2018 for
the management of feline weight loss. This followed a series of clinical trials (see
below) into the
use of mirtazapine in this form, though not all of the trials used Mirataz.
Mirataz was developed by a company called
KindredBio, working in conjunction with Dr Jessica Quimby. In March 2020
KindredBio
announced that Mirataz had been
sold to Dechra Pharmaceuticals plc in the UK for US$43M plus a share in the
profits from ongoing sales. The sale was completed in April 2020.
Mirataz continues to be available
in the USA.
Dechra launched Mirataz in the UK
and Europe in March 2021, to be followed by other international markets.
The European Medicines Agency
(2020) discusses the approval of Mirataz in the EU.
It was previously possible to obtain transdermal mirtazapine from a
compounding pharmacy in the USA, but in theory this is no longer permitted now
that Mirataz has
received regulatory approval.
Dechra provides more information about the mechanism of and
approval process for Mirataz.
Mirtazapine Dosage:
Amount and Frequency
There has been a lot
of debate over the years about how much mirtazapine to give to a CKD cat and
how often. The dosage and frequency may vary depending upon whether you are
using tablets or the transdermal form.
Mirtazapine Transdermal (Mirataz) Amount and Frequency
Mirataz
recommends applying a 1.5 inch
"ribbon" of the ointment to the inner pinna (top part) of the cat's ear,
which it says is roughly 2mg, equivalent to 1ml. You should wear gloves when
applying the ointment.
It advises doing this once daily for fourteen days.
However, that advice applies to cats without CKD. In CKD cats, you would not
normally start with daily dosing. There is more information about research
into dosing frequency
below,
but
Drug-dosing adjustment in dogs and cats with chronic kidney diease
(2022) De Santis F, Boari A, Dondi F & Crisi PE Animals (Basel)
12(3) pp262 states "The half-life of oral mirtazapine is prolonged in
elderly cats (12.1 h) and cats with CKD (15.2 h). It does add "There are
differences in pharmacokinetics among formulations, with a lower mean peak
and total plasma concentration recorded with a transdermal ointment than
oral dosing," which would include Mirataz, but nevertheless states "Given
the prolonged half-life of mirtazapine in CKD cats, oral administration of
the medication every 48 h is recommended. To minimize its adverse effects,
the dosage should be titrated to the lowest effective dose for appetite
stimulation with both the oral and transdermal formulations."
People using other forms of
compounded transdermal mirtazapine
seem to use the same dose as those giving tablets.
2022 Consensus guidelines on management of the
inappetent hospitalised cat (2022) Taylor S, Chan DL, Villaverde C, Ryan L, Peron
F, Quimby J, O’Brien C & Chalhoub S Journal of Feline Medicine and
Surgery 24 pp614-640 state "For clinicians used to using
transdermal mirtazapine, it should be noted that the appetite effect after
administration may be more subtle in some patients than seen with oral
mirtazapine. This is likely due to a flatter drug concentration curve and
lower peak serum concentrations, a phenomenon that also results in fewer
adverse effects with transdermal administration."
Mirataz should be discarded 30 days after
opening.
VetRXDirect
sells
Mirataz for US$47.38.
Thriving Pets in the USA sells Mirataz for US$49.95. You will need a
prescription. If you spend over US$100, you will get a 5% discount with the
code Tanya.
Pet Drugs Online in the UK sells Mirataz for £46.28.
Mirtazapine Tablets: Amount
It used to be
common to give CKD cats
1.88 mg to 3.75 mg (⅛ to ¼ of a 15
mg tablet) of mirtazapine every three days. This worked well for many cats,
but caused problems for some others.
Mirtazapine toxicity in cats: retrospective study of
84 cases (2006-2011)
(2015) Ferguson LE, McLean MK, Bates JA &
Quimby JM Journal of Feline Medicine and Surgery 28(11) pp868-874 examined the records from the
ASPCA's Animal Poison Control Center. It found that a dose of 3.75mg was
associated with signs of toxicity in 25 of the 84 cats in the study. The
study concludes: "The greater number of adverse effects at 3.75 mg rather
than 1.88 mg suggests that the latter may be a more appropriate starting
dose for stimulating appetite while limiting toxicity."
Plumb's Veterinary
Drug Handbook (2015) also recommends starting with the 1.88 mg (⅛
of a 15 mg tablet).
If you are using tablets, I would
therefore suggest starting with the lower dose of 1.88mg
(⅛
of a 15 mg tablet).
Mirtazapine Tablets: Frequency
The original dosing
frequency for cats was only once every three days.
Mirtazapine tablets usually
take effect pretty quickly, within a couple of hours, though they do work more
slowly for some cats. However, there
has been a lot of debate about how long mirtazapine in tablet form lasts for and how often it can be
given, particularly since,
like cyproheptadine
below,
it appears that mirtazapine may become less effective for some cats over
time, and therefore only being able to give the medication every three days
could be problematic.
A
study at Colorado State University,
The pharmacokinetics of mirtazapine in cats with chronic kidney disease and
in age-matched control cats (2011) Quimby
JM, Gustafson DL & Lunn KF Journal of Veterinary Internal Medicine
25(5) pp985-9, found that the half life of the drug in tablet form (the time it takes
for 50% of the medication to leave the body after taking it) was shorter than originally thought and
that therefore a 48 hour dosing interval was acceptable.
The Veterinary
Teaching Hospital at Colorado State University has been prepared to give
mirtazapine daily if required, particularly to late stage cats.
Single dose pharmacokinetics following transdermal
and oral administration of mirtazapine 2% transdermal ointment in cats
(2017) Mason B, Buhles W, Quimby J, Labelle
D, Jung D, O’Banion MP, Lee J & Markey S Journal of Veterinary Internal
Medicine (2017 ACVIM Forum Research Abstract Program) 31(4)
p1334 looked at the effectiveness of oral versus transdermal
mirtazapine. It found that absorption of oral mirtazapine "was faster and
more consistent" than the transdermal form. It also found that transdermal
mirtazapine had a much longer half-life (the time needed until the body
clears half of the amount given, leaving 50% still in the body) of 26.8
hours versus 10.1 hours for the tablet form.
In light of this finding, i.e., since half
the amount given has left the body after only ten hours, it is possible that
daily dosing of mirtazapine will become more prevalent.
Mar Vista Vet says that mirtazapine tablets
work best when a smaller dose is given daily.
However,
because of the risk of serotonin syndrome, it is
wise to start with an every three day dosing schedule, only increasing the
frequency if necessary and of course with your vet's agreement.
Mirtazapine
Research
Drug exposure and clinical effect of
transdermal mirtazapine in healthy young cats: a pilot study
(2017) Benson KK, Zajic LB, Morgan PK, Brown SR, Hansen RJ, Lunghofer PJ,
Wittenburg LA, Gustafson DL, Quimby JM Journal of Feline Medicine and
Surgery 19(10) pp998-1006 looked at the use of transdermal mirtazapine in healthy cats and
found that "the dose required is likely much larger than what is generally
given orally. A consequence of this higher dose was an increased incidence
of agitation and other negative effects."
Safety of mirtazapine 2% transdermal ointment
administered topically to cats at 5mg/kg for 28 days
(2017) Avenatti A, Buhles W,
Quimby J, Labelle D, O’Banion MP Journal of Veterinary Internal
Medicine (2017 ACVIM Forum Research Abstract Program) 31(4)
p1333, examined the effects of doses much higher than typically used, in
both healthy cats and two CKD cats (one in Stage 1, one in Stage 2, but both
much younger than most CKD cats), given for 28 days. Many of the cats
developed irritated ears where the medication was applied, and one of the
CKD cats had a week of vomiting which resolved without treatment. There were
no changes in bloodwork or blood pressure in any of the cats, and they
did all gain weight. The study concludes "Mirtazapine 2% transdermal ointment was well tolerated in cats when
administered at 5 mg/kg for 28 consecutive days."
Single dose pharmacokinetics following transdermal
and oral administration of mirtazapine 2% transdermal ointment in cats
(2017) Mason B, Buhles W, Quimby J, Labelle
D, Jung D, O’Banion MP, Lee J & Markey S Journal of Veterinary Internal
Medicine (2017 ACVIM Forum Research Abstract Program) 31(4)
p1334 looked at the effectiveness of oral versus transdermal mirtazapine in
healthy cats. It found that absorption of oral mirtazapine "was faster and
more consistent" than the transdermal form. It also found that transdermal
mirtazapine had a much longer half-life (time until the body cleared half of
the amount given, leaving 50% still in the body) of 26.8 hours versus 10.1
hours for the tablet form. This may mean that it is appropriate to give
transdermal mirtazapine less frequently than the oral version, though that
is in fact not the recommended dosing schedule for Mirataz.
This may be because of another paper,
Multiple dose pharmacokinetics of mirtazapine 2% transdermal ointment in cats
(2017) O’Banion MP, Buhles W, Quimby J, Labelle
D, Jung D, Jung D Journal of Veterinary Internal
Medicine (2017 ACVIM Forum Research Abstract Program) 31(4)
p1335, which concluded "After
once daily dosing for 14 days, mirtazapine 2% transdermal ointment achieves
clinically relevant serum concentrations in cats."
Safety of mirtazapine 2% transdermal ointment
administered topically to cats at 5 mg/kg for 28 days
(2017)
Avenatti A, Buhles W, Quimby JJ, Labelle
D & O’Banion MP Journal of Veterinary Internal
Medicine (2017 ACVIM Forum Research Abstract Program) 31(4)
p1333 states "Mirtazapine 2%
transdermal ointment (2% MZP) achieves clinically relevant serum
concentrations in cats and results in increased body weights at a dose of
0.5 mg/kg." The study looked at the safety of giving higher dosages (2mg/kg)
to both healthy cats and CKD cats, and concluded "Mirtazapine 2% transdermal
ointment was well tolerated in cats when administered at 5 mg/kg for 28
consecutive days."
Assessment of compounded transdermal mirtazapine as an
appetite stimulant in cats with chronic kidney disease
(2020) Quimby JM, Benson KK, Summers SC,
Saffire A, Herndon AK, Bai S & Gustafson DL Journal of Feline Medicine
and Surgery 22(4) pp376-383 looked at the use of compounded transdermal
mirtazapine (not Mirataz) in cats in Stage 2 or 3 CKD. The dosages used were 1.88 mg/0.1ml
every other day or 3.75mg/0.1ml. Both strengths led to an increase in appetite, food intake
and weight, but an increase in BUN was also seen. Some of the cats exhibited
excessive howling.
Mirtazapine Side
Effects
If you are using Mirataz, a transdermal
form of mirtazapine applied to the ear, the ears may become red and
irritated.
As a tetracyclic anti-depressant,
mirtazapine may cause an increase in blood pressure and heart rate. Having
said that, Plumb's Veterinary Drug Handbook says that it may cause orthostatic
hypotension (low blood pressure) so should be used with caution in patients with heart problems.
It may increase cholesterol levels. Some members of my support group have
seen increased urination.
Occasionally you may see reduced
white blood cells.
Like cyproheptadine, it may make some
cats restless, agitated and vocal (to such an extent in some cases that it
is known on
Tanya's CKD Support Group
as meowzapine), although around 50% of human patients on mirtazapine feel
sleepy.
In some cases, you may
see a severe reaction known as serototin syndrome (see
below).
Mirataz says Mirataz
should be used with caution in cats with kidney disease.
Mirtazapine and Serotonin Syndrome
In 2007
I heard
from
a lady whose CKD cat had an extremely severe
reaction to mirtazapine, and her
cat's reaction lasted for around three days. A poison centre was unable to
offer any suggestions, so she just had to wait for the drug to work its way
out of her cat's system.
I subsequently learnt
that when cats react badly to mirtazapine, it is often because their bodies
are creating too much of a neurotransmitter called serotonin. As explained
above, mirtazapine works via its effects on serotonin receptors.
Mirtazapine is supposed to stop serotonin being bound to receptors in nerve
cells, which leads to increased levels of serotonin in the brain, which then
in turn leads to increased appetite Unfortunately, if too much
serotonin accumulates in the cat's brain, it can lead to a condition called
serotonin syndrome. Although this reaction is not common, I have since heard
from several other people whose cat experienced it, and this is probably
because, as
Serotonin syndrome
(2013) Almgren CM & Lee
JA Clinician's Brief Oct 15 pp11-15 states,
the risk is higher in CKD patients. Therefore please be aware of the
possibility, and be sure to start with a really small dose as outlined
above.
Symptoms of serotonin
syndrome include a fast heart rate, hypertension (including dilated pupils),
excessive vocalisation (meowing loudly or howling), being "spaced out",
walking strangely, stumbling, pacing up and down, breathing problems such as
panting or breathing very fast, increased body temperature and agitation.
You may see some of these symptoms to a lesser degree in any cat on
mirtazapine (we don't call it meowzapine for nothing) but the degree of the
symptoms is what matters.
Drugs says that using
ondansetron (a nausea treatment) and mirtazapine together may increase
the risk of serotonin syndrome.
Mar Vista Vet
mentions that the risk
of serotonin syndrome is higher if you are using a painkiller called
tramadol at the same time.
Serotonin syndrome
(2013) Almgren CM & Lee
JA Clinician's Brief Oct 15 pp11-15 states that
"untreated,
serotonin syndrome can result in death." Please don't panic, that paper is
talking about serotonin syndrome generally, including cases of cats and dogs
who have accidentally eaten human-sized doses of mirtazapine or other
medications. To date I have not heard of any cat given a cat-sized dose of
mirtazapine who has died. However, I would certainly recommend contacting
your vet if you think your cat has serotonin syndrome, and you might feel safer taking your cat to the vet.
The
antidote for serotonin syndrome caused by mirtazapine is actually another
drug commonly used as an appetite stimulant in cats,
cyproheptadine.
Treatment of the serotonin syndrome with cyproheptadine
(1998) Graudins A, Stearman A & Chan B The Journal of Emergency Medicine
16(4) pp615-9 explains more about this. One possible dose would be 2mg
given twice within the first 24 hours, followed by 1 mg given twice daily
for the next 48 hours; but do not give this without your vet's knowledge and
approval. Depending upon the severity of your cat's case, additional
treatments such as IV fluids or inducing vomiting may also be necessary.
Try not to worry too much. All the cats I
have heard about with serotonin syndrome were back to normal within a few
days.
Mirtazapine toxicity in cats: retrospective study of
84 cases (2006-2011)
(2015) Ferguson LE, McLean MK, Bates JA &
Quimby JM Journal of Feline Medicine and Surgery 18(11)
pp868-874 found that "For cats with
available information, the onset of clinical signs ranged from 15 mins to 3
h, and resolution of clinical signs ranged from 12-48 h." So any problems
should be resolved within 12 hours to a maximum of two days.
Serotonin syndrome
(2013) Volpi-Abadie J, Kaye AM & Kaye AD The
Ochsner Journal 13(4) pp533–540 explains more
about serotonin syndrome generally.
Mirtazapine Interactions
Most people I have heard from have not
had problems with mirtazapine,
but I
have heard from
a couple of people whose cats were on treatment for hyperthyroidism who did
not seem to do well on mirtazapine. This is probably because, as mentioned
by
The University of Maryland Medical Center,
methimazole, a commonly used medication for
hyperthyroidism, reduces levels of
a liver enzyme
called CYP2D6 that helps to
clear mirtazapine from the body.
If your cat is on methimazole and you want to use
mirtazapine, I would talk to your vet about using a reduced dose of
mirtazapine.
Drugs says that using
ondansetron (a nausea treatment) and mirtazapine together may increase
the risk of serotonin syndrome.
Mar Vista Vet
mentions that the risk
of serotonin syndrome is higher if you are using a painkiller called
tramadol at the same time.
Drugs says that using mirtazapine at the same time
as
gabapentin, a painkiller, may increase side effects such as dizziness
and drowsiness.
Mirataz states that mirtazapine should not be used in cats who have taken
selegiline in the last fourteen days, and
selegiline should noy be taken for fourteen days after stopping
mirtazapine, because doing so
increases the risk of
serotonin syndrome.
Cyproheptadine (Periactin)
Cyproheptadine (Periactin) is an
antihistamine that in cats may have the side effect of stimulating appetite.
It has historically been a popular choice, and I have used it in my own
cats.
Since cyproheptadine is not really
designed to be an appetite stimulant (and indeed may not work for all cats),
dosage can be rather hit and miss, so you should be guided by your vet.
It is best to start with a
low dose because damaged CKD kidneys eliminate cyproheptadine
more slowly than those of a healthy cat. Increase the
dose only if necessary — you are aiming for a dosage
which stimulates your cat to eat whilst minimising the chance of side
effects.
Possible side effects
include faster breathing,.
agitation (often accompanied by
howling), or
the opposite effect of lethargy.
In a small number of cats it may cause
reduced
urination or an increased heart rate or
temperature. If you see such symptoms, check with your vet because the dosage you
have used could well be too high for your particular cat.
Cyproheptadine is
available as 4mg tablets. Whilst
Plumb's Veterinary Drug Handbook mentions a dose
of 1 - 4mg once or twice a day for a cat, many people on
Tanya's CKD Support Group have found a dose of 0.5mg once per day
works well and also seems to reduce the risk of the side effects mentioned
above. Therefore you may wish to ask your vet if you can start at this level,
increasing it only if necessary.
According to
Disposition of cyproheptadine in cats
after intravenous or oral administration of a single dose
(1998)
Norris CR,
Boothe DM,
Esparza T,
Gray C,
Ragsdale M,
American Journal of Veterinary Research 59(1) pp79-81, you may
need to give cyproheptadine for approximately 2.5 days before it reaches a
steady level in the cat, but some people have found that even one dose can
take effect pretty quickly. Once the cat has been on cyproheptadine for a
few days, it should certainly take effect within a couple of hours, although
some cats develop appetite within 15 minutes, so be sure to have fresh food
ready for your cat.
You may choose to use cyproheptadine for
a few days and then see if you can manage without it, but if you find you
need to use it on a longer-term basis, this appears to be safe, though its
effectiveness may gradually reduce, and the cat may sneeze as the effects
wear off. If you use cyproheptadine longer term, monitor
BUN levels (which you are probably doing anyway), because these may
occasionally increase when using cyproheptadine.
Mar Vista Vet
mentions that cyproheptadine "is best avoided in patients with glaucoma,
recovering from urinary blockage, and heart failure patients."
Cyproheptadine is available in Canada and
the UK without a prescription, but please do not use it on your cat without your
vet's knowledge and approval.
Thriving Pets in the USA sells cyproheptadine. You will need a
prescription. If you spend over US$100, you will get a 5% discount with the
code Tanya.
Cyproheptadine Interactions
and Side Effects
Disposition of cyproheptadine in cats
after intravenous or oral administration of a single dose
(1998)
Norris CR,
Boothe DM,
Esparza T,
Gray C,
Ragsdale M
American Journal of Veterinary Research 59(1) pp79-81 found that
when cyproheptadine is used at the same
time as oral potassium citrate or oral potassium chloride in solid form, it
may increase the risk of the potassium irritating the stomach.
Drugs has more information on this.
As far as I can tell, this does not seem to apply to potassium gluconate.
Plumb's Veterinary Drug Handbook mentions that
cyproheptadine may have calcium channel blocking effects and thereby cause
low blood pressure. The Norris study above also
states that cyproheptadine is "contra-indicated in cases of
hypertension." There is a small risk that
using cyproheptadine in combination with a drug used to treat
hypertension,
amlodipine (a calcium
channel blocker), may reduce blood pressure too far.
Many people do
seem to use both cyproheptadine and oral potassium supplements with no
problem, and many people also use cyproheptadine in cats with high blood
pressure, but you should discuss these issues further with your vet.
Pet
Place also provides an overview.
Cetirizine (Zyrtec)
Like cyproheptadine, cetirizine is an
antihistamine, and therefore vets regularly prescribe it for allergies.
An open clinical trial on the efficacy of cetirizine
hydrochloride in the management of allergic pruritus on cats
(2012) Griffin JS, Scott DW, Miller WH &
Tranchina MM Canadian Veterinary Journal 53(1) pp 47–50
reports on its use for allergic itch and states that "no adverse side
effects were reported." The cats in this study did not have CKD.
I have not heard of any vet prescribing
cetirizine as an appetite stimulant, but a number of people on Tanya's Support
Group have found it does seem to be an effective appetite stimulant for
some CKD cats.
Cetirizine is widely available under
the brand name of Zyrtec or as a generic. Make sure you do not buy Zyrtec D
by mistake, because, as mentioned by
Veterinary Partner, this also contains pseudoephedrine, which is not suitable for
cats.
Although cetirizine is available over
the counter, do not use it without talking to your vet first because it
has not been widely tested in cats, and as far as I know, it has never
been tested in CKD cats.
Why I love Zyrtec for cats
(2010) is an article by Dr P Khuly. Scroll down to
the article (no need to create an account to read it).
Cetirizine Dosage
Cetirizine is usually available in 5mg
or 10mg tablets, and is dosed once daily. As with the other medications
used as appetite stimulants, start at a low dose and only increase if
necessary. Here are some of the dosages seen on my support group:
Be guided by your vet as to the best
dose for your cat.
Cetirizine Side
Effects
Drugs points out that since cetirizine is
excreted mainly via the kidneys, "Patients with renal and/or liver disease
may be at greater risk for adverse effects from cetirizine due to
decreased drug clearance." It adds that the manufacturer recommends a
dosage reduction for humans with reduced kidney function.
Pet Place states
"The most common adverse effects of cetirizine are sedation, lethargy,
vomiting, drooling
(hypersalivation), and lack of appetite" (yes, the opposite of what you
are trying to achieve).
Capromorelin (Elura or Entyce)
Capromorelin is a ghrelin receptor agonist
that works by
mimicking ghrelin. Ghrelin is often called the hunger hormone because it sends
messages to the brain telling it you are hungry, thus triggering
appetite.
Capromorelin: a ghrelin receptor agonist and novel
therapy for stimulation of appetite in dogs
(2018) Rhodes L, Zollers B, Wofford JA & Heinen E
Veterinary Medicine and Science 4(1) pp3–16 explains more about
how it works.
Capromorelin under the name of Entyce is approved by the US Food and Drug Administration for the
stimulation of appetite in dogs. It became commercially
available in the USA in October 2017, in 10 mL, 15 mL and 30 mL bottles.
It is normally given once daily.
Capromorelin under the name of
Elura was
approved in the USA in 2020 for the treatment of unintended weight loss
in CKD cats.
The US Food & Drug Administration
(2020) reported on the approval. The
product became commercially available in the USA in April 2021. It is availble in liquid form, and the usual dose is
2mg/kg once daily.
I find it a little surprising that
capromorelin was approved in this way, firstly because an
appetite stimulant does not automatically minimise weight loss, and
secondly because capromorelin should be used with caution in
patients with kidney disease, particularly in dehydrated cats.
However, in a short (56 day) trial the
medication did increase weight in 80% of the CKD cats in the study.
A few members
of Tanya's CKD Support Group have tried capromorelin in their CKD cats,
but reports thus
far are disappointing, with members stating it did not seem to really help
with appetite but did seem to cause lethargy. This is a known side effect
in cats:
Evaluation of the safety of daily administration of
capromorelin in cats (2018) Wofford JA,
Zollers B, Rhodes L, Bell M & Heinen E
Journal of Veterinary Pharmacology
and Therapeutics 41(2) pp324-333 reports on the results of
safety studies and states that side effects seen included lethargy.
Other side effects that were seen were vomiting, drooling, headshaking and
lipsmacking. For some reason, vomiting and drooling were more common in
male cats.
The US Food & Drug Administration
(2021) states that capromorelin should not be used in cats who are
dehydrated or who have heart disease, and that it may not be appropriate
for cats with diabetes.
2022 Consensus guidelines on management of the
inappetent hospitalised cat (2022) Taylor S, Chan
DL, Villaverde C, Ryan L, Peron F, Quimby J, O’Brien C & Chalhoub S
Journal of Feline Medicine and Surgery 24(7) pp614-640 states
"it is recommend [sic] that this medication not be used in patients with
significant systemic compromise, which likely precludes its use in
hospitalised patients."
Managing inappetence and chronic kidney disease
(2021) Larsen JA, Marks N, Bullen L & Wood MA
Clinician's Forum discusses the use of Elura in CKD cats (this forum
appears, by an amazing coincidence, to have been sponsored by the
manufacturer of Elura.
Drugs has some
information on capromorelin.
Diazepam (Valium)
Diazepam (Valium), a tranquilliser and
muscle relaxant, is sometimes used as an
appetite stimulant. Diazepam has a number of side effects, including affecting depth
perception which can be dangerous for cats allowed outdoors. It may also
cause ataxia (loss of co-ordination or an unsteady walk). In some cases,
although it is a tranquilliser, diazepam may have the paradoxical effect of
causing aggression.
The main problem with diazepam is that
unfortunately a small number of cats develop acute liver failure after
several days of use.
Fulminant hepatic failure associated with oral
administration of diazepam in 11 cats
(1996) Center SA, Elston TH, Rowland PH, Rosen DK,
Reitz BL, Brunt JE, Rodan I, House J, Bank S, Lynch LR, Dring LA
& Levy JK
Journal of the American Veterinary Medical Association 209
pp618-25 reports on the risks of using diazepam in cats, and concludes that
some cats have an idiopathic (i.e. the precise reason is unknown) response
to this medication. Some cats just appear to be sensitive to it, and it is hard to
know beforehand which cats would react in this way.
Pharmacological appetite stimulation: rational choices
in the inappetent cat (2014) Agnew W &
Korman R Journal of Feline Medicine and Surgery 16(9) pp749-56
says "The use of oral
benzodiazepines is controversial in cats due to multiple reports of serious,
and almost invariably fatal, idiosyncratic hepatotoxicity observed 5–13 days
after the use of oral diazepam. These drugs are reportedly either
contraindicated, or only to be used with caution/at reduced rates, in
patients with hepatic dysfunction. Caution is also required in patients
with renal disease. As viable, effective alternatives exist, the use of
these drugs has largely been superseded."
Although some people have had good
results with diazepam, I personally would not risk it; if you choose to use
it, I would suggest you do so as a last resort. If you do choose to use it,
your vet should check your cat’s liver values before starting it and a few
days afterwards.
Mar Vista Vet has
more information on using diazepam in cats, including a comment that
diazepam may have a stronger effect if used at the same time as
cimetidine
(Tagamet); and it may
heighten the effect of Digoxin, a heart medication.
Pet Place discusses
the pros and cons of using diazepam.
Steroids (as Appetite Stimulants)
Your vet may offer you a steroid if your
cat is not eating very much. There are two classes of steroids,
corticosteroids and anabolic steroids, and both may help stimulate appetite.
Corticosteroids
It is recommended that corticosteroids should not be used in the renally impaired,
so they are not a good choice as an appetite stimulant..
Corticosteroids can have serious side effects with long-term use
(including triggering diabetes, fluid retention and resulting hypertension,
and masking infections), and may also increase
gastric hyperacidity, which is not
ideal for a CKD cat. In one study, some cats
developed a unique form of
congestive
heart failure seven days of starting steroids.
If for some reason you are using corticosteroids, these should never be
suddenly discontinued: the dose must be tapered because using
corticosteroids may suppress the adrenal glands' ability to produce
cortisone naturally. Tapering the dose minimises the risk of adrenal
insufficiency occurring as a result.
See
Treatments for more information about corticosteroids.
Anabolic Steroids
Anabolic steroids may help
stimulate appetite, and may also be beneficial for CKD cats with muscle
wasting and mild
anaemia.
If you are using steroids as an appetite stimulant, particularly longer
term, anabolic steroids are a much safer choice than corticosteroids.
Your vet may prescribe anabolic
steroids in the form of either tablets or injections. An anabolic steroid
used in Europe is
Laurabolin
(injectable nandrolone).
Winstrol-V (stanazole)
was popular in the US but
it appears to have been unavailable since September 2004, which apparently
is related to some type of FDA regulation. It may still be obtainable from
some compounding pharmacies.
Drugs warns that Winstrol-V may
cause severe liver disease in cats. Medical management of chronic kidney
disease in cats
(2015) DiBartola S says "The use of anabolic
steroids (e.g., stanozolol) in CKD is empirical and their efficacy remains
to be documented. The margin of safety for the commonly used anabolic
steroid, stanozolol in cats is narrower than in dogs and it may result in
hepatotoxicity characterized by hepatic lipidosis and cholestasis with
minimal hepatocellular necrosis. Thus, use of anabolic steroids in cats with
CKD is not recommended."
Thomas took anabolic steroids
whilst he had CKD. He received a monthly shot at the vet's. We were able to
reduce Thomas's steroid dose, but he still seemed to do better overall when
he was taking his steroids.
If you are using steroids as an appetite
stimulant only, I suggest trying the other ways of encouraging your cat to
eat outlined above first, keeping steroids in reserve for later on in the disease. If you
do use steroids, opt for anabolic ones and your vet should monitor liver
values, because these sometimes increase with steroid use, in which case the
steroids should be discontinued.
See
Treatments for more information about anabolic steroids.
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This page last updated: 01 July 2025
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