Subcutaneous fluids are fluids given under the skin. This means they can
be given at home.
In the
USA and Canada, it is common to give sub-Qs to CKD cats to prevent
dehydration. Unfortunately, sub-Qs are not routinely offered in most
other countries.
This page
explains the basics of sub-Qs, including when to start them, how much to
give and how often.
Subcutaneous
means under the skin; so subcutaneous fluids, commonly known as sub-Qs
in the USA and subcuts in the UK,
are a way of hydrating the cat by carefully introducing fluids under the skin. Instead of placing a slow drip
of fluids into the cat's vein, as happens with intravenous (IV) fluids, the fluid is injected
just under the skin with a needle. Giving sub-Qs only takes about five
minutes and can be easily done by a trained layperson.
The fluid then gradually disperses throughout the cat's body, and helps
him or her to maintain hydration at the correct level.
The
fluids used are particular types of fluid with the correct balance
of electrolytes (salts). There are various types of fluids available (see
Tips on Giving Subcutaneous Fluids) and your vet can select
the fluid most suitable for your cat.
The cat is
an unusual animal in that it has the ability to concentrate its urine, a
little like a camel; this is believed to be a legacy of its African
heritage. However, in cats with CKD, this ability gradually disappears,
and cats then produce a very dilute urine: the urine looks weaker in
colour, has little odour, and the cat will often produce copious
amounts.
This increase in urination leads the cat
to drink more and more in order to try to avoid becoming dehydrated; and
for a time the cat can manage to maintain some kind of balance.
Eventually, however, the cat simply cannot drink enough to keep up with
its urination rate, and dehydration (which doesn't only mean a loss of body fluids,
but also of electrolytes necessary for proper function) occurs. Sometimes this becomes so
severe that the cat crashes (i.e. becomes dehydrated enough to need IV
treatment at the vet's), as happened to Thomas.
Even if your cat does not suffer such a crisis, the ongoing low-level
dehydration that accompanies CKD can be debilitating and uncomfortable; can
cause toxin levels in the blood to rise; reduces blood flow
through the kidneys, and the kidneys deteriorate even more. Human CKD
patients have described dehydration and the accompanying high levels of toxins
in the blood as feeling similar to a bad hangover. Therefore the purpose of sub-Qs
is
to keep your cat nicely hydrated, which in turn should help maintain kidney function and
improve his or her well-being by removing that hungover feeling.
Although sub-Qs can be of great benefit to cats who need them, not all CKD
cats need them immediately. As mentioned above, the purpose
of sub-Qs is to keep the cat hydrated enough to avoid dehydration occurring. However,
cats with early stage CKD can usually drink enough to offset their increased
urination, and thus do not become dehydrated even without sub-Qs.
Processing sub-Qs in itself places an additional
workload on the kidneys, plus it can flush out certain nutrients, reduce
potassium levels and raise sodium levels.
In
Staged management of chronic kidney disease in
dogs and cats (2009), a Presentation to the 34th World
Small Animal Veterinary Association World Congress, Dr David Polzin
states "Because recent evidence suggests excessive sodium intake may
harm the kidneys, recommendations for long-term sodium administration in
any form should be carefully considered."
Giving too many fluids or too soon may also
increase the risk of
overhydration. This is a particular risk for cats with
heart
problems. Therefore it is best not to begin fluids until the
advantages are likely to outweigh the disadvantages i.e. when a cat
would become dehydrated without them.
Dr Katherine James of the
Veterinary Information
Network believes that this tends to happen and that most
CKD cats will benefit from subcutaneous therapy once creatinine levels are
consistently over 3.5-4.0 US (300-350 international). This equates to high Stage 3
of the IRIS staging system. If your vet thinks your cat's
CKD is less advanced than this, and your cat does not appear
dehydrated,
then it is probably safer to hold off on sub-Qs for the moment.
However, there are exceptions, and
a small number of cats with creatinine below 3.5 US (300 international) may need sub-Qs. This
tends to apply to cats whose creatinine is below 3.5 US (300
international) but who previously had a higher
level, usually at diagnosis. So if, for example, your cat has creatinine of
6.0 US (550 international) at diagnosis, but this gradually falls to 3.5
US (300 international), s/he will still probably
benefit from regular sub-Qs. Cats with pancreatitis are prone to dehydration
and may need sub-Qs even if their creatinine level is lower than 3.5 US
(300 international).
Also, any
time more water is going out than is coming in, sub-Qs may be needed
short-term. Thus, a CKD cat who is
a bit below par because of vomiting or diarrhoea causing dehydration, or
who stops eating or drinking, may
benefit from sub-Qs as a one-off - my vet gave sub-Qs to my non-CKD cat
when she had severe vomiting and diarrhoea for this reason.
This is something you need to discuss with your vet, to decide what is
right for your cat. When you see recommendations regarding the amount of
fluid that a cat needs each day, be aware that often this is total fluid
amount. Cats obtain much of their daily fluid requirement from their food
and water (most canned food is around 80% water). Therefore Dr Katherine James
of the
Veterinary Information Network believes that generally speaking, cats do not need more than 100ml
of sub-Q fluids a day,
though there are exceptions, for example if your cat is
particularly large or particularly small.
In
Staged management of chronic kidney disease in dogs
and cats (2009), a Presentation to the 34th World Small
Animal Veterinary Association World Congress, Dr David Polzin states:
"In patients with signs consistent with chronic or
recurrent dehydration, long-term subcutaneous fluid therapy may be
considered. Typically, a balanced electrolyte solution (e.g., lactated
Ringer's solution) is administered subcutaneously every one to three days
as needed. The volume administered depends upon patient size with a
typical cat receiving about 75 to 100 ml per dose."
Based on what I have seen over the years, the average 8-10lb cat would
usually be given around
100ml a day. Larger cats might need 125ml or even occasionally 150ml for
cats who weigh 15lb or over, whilst smaller
cats need smaller amounts, 50-75ml a day. Be cautious with cats with
heart problems,
who may have problems processing sub-Qs, and who may need smaller amounts,
perhaps given more frequently, for example 50ml twice a day rather than
100ml once a day.
Colorado State University College of Veterinary
Medicine states "no more than 5 to 10
ml/lb should be given at each injection site" so giving 100ml in one place
should not be a problem for a 10lb cat.
Since cats vary in their individual needs, you should seek your vet's advice on how much to give your cat, and start
off gradually, and aim for the lowest level that will comfortably maintain
hydration. If you live in a hot humid area without air conditioning, your
cat might need more fluid than a cat in a colder climate. If your cat has
a bout of vomiting or diarrhoea or is not eating, more fluids might be
required in the short term to offset the fluid lost as a result of the
crisis.
I suspect that some cats who
have had severe crashes may possibly require more fluids than cats who are
diagnosed early and whose CKD progresses gradually. Thomas wasn't a
massive cat, but he still required 300ml a day to start with following his
crash. Even after his creatinine level stabilised at 316 (US: 3.5), he
still required
200ml a day, divided into two sessions, in order to maintain hydration.
The key words in the previous sentence are "in order to maintain hydration".
If your cat's bloodwork worsens, this doesn't automatically mean that the
fluid amount should be increased. Giving more than
is needed to maintain hydration is a strain on the kidneys (see
when to use subcutaneous fluids),
can make a cat feel uncomfortable, and of course costs more.
When
deciding on how much fluid to give, you need to monitor your cat for
dehydration and
check that the fluid is being
properly absorbed. A
pouch is normal, and it usually
takes 6-8 hours for the fluids to be absorbed, though some cats take
longer. Many people find the simplest way to monitor their
cat's need for fluids is by means of a
weighing scale: you can weigh your cat regularly and if his/her weight goes down,
this may indicate dehydration; if the cat's weight increases, the cat may
be retaining fluid and at risk of overhydration.
Coco's
Page has more information on how to do this.
If you have the
level of sub-Qs right, your cat will no longer drink massive amounts of
water.
If your cat's bloodwork improves, or your cat seems to stop absorbing the
fluids, it may be that s/he needs fewer or no fluids. Ask your vet about
reducing or stopping the fluids, but this should be done gradually so as
to give your cat's damaged kidneys time to adjust. The same applies if your vet
has prescribed fluids for a low numbers cat - ask about stopping fluids to
see how your cat manages, but do it slowly.
Fluids are not a benign treatment and more is not always better - giving
too much fluid can be dangerous. Unfortunately I have noticed that some
vets recommend giving rather large amounts of fluid. In most cases this is
not necessary, and in fact carries risks: it increases the sodium load on
the kidneys, which may contribute to the development of hypertension, and
in the worst case it may cause overhydration. Some vets claim that it is
impossible to overhydrate a cat with sub-Qs, but if you give a 10 lb cat
300ml of fluids a day, that is the equivalent of giving a 150lb person 4.5 litres
of water a day, far in excess of the amount most people (or cats) can
process. I have heard from a number of people who have learnt the hard way
about the risks of overhydration, and some of their cats sadly died as a
result. In
Renal disease (2006), Dr
D Polzin
states
"Chronic subcutaneous fluid therapy can result in
fluid overload in some patients, particularly when fluid volumes in excess
of those recommended here are used. We have seen several cats given large
quantities of fluid (200 to 400 ml/day) present with severe dyspnea due
to pleural effusion. This condition can usually be avoided by reducing
the volume of fluids administered." He mentions that the
presence of metabolic acidosis increases the risk of pulmonary oedema in
cats receiving fluid therapy..
Don't panic over this but do keep an eye on your cat when administering
sub-Qs and watch for the warning signs of
overhydration.
See above for tips on gradually reducing the amount of fluid you give.
Coco's
Page has information on calculating how much fluid is necessary,
though please do not alter the amounts you give without your vet's
knowledge and approval.
This depends to a large extent upon your cat's individual needs. The
majority of cats receive sub-Qs every day. However, some cats on
Tanya's CRF Support Group only need fluids 2-3 times a week; whilst a small
percentage, like
Thomas, become dehydrated very quickly without twice daily fluids (these
cats are often cats who have suffered a severe crash at diagnosis).
Discuss your cat's particular requirements with your vet, and aim for a
consistent, regular approach.
It is usually better to give smaller amounts more often, e.g. to give 100ml
every day rather than 200ml every other day. If you think about it, this makes
sense - if your goal is to drink eight glasses of water each day, it is better if you drink
eight each day rather
than sixteen on one day and nothing at all on the next day - the same principle
applies to sub-Qs.
I don't really understand why vets sometimes recommend sub-Qs once a week. It
seems too infrequent to make any real difference. However, it can certainly be
worth giving sub-Qs as a one-off to a cat who develops dehydration from
vomiting or diarrhoea, or if you experience a heatwave and don't have air
conditioning.
Every now and then, you may have to skip a sub-Q sesssion, perhaps because
you are sick or your cat refuses to co-operate. Missing one session is not
cause for concern with most cats, but aim for consistency overall.
If
you start fluids at the right time, i.e. only when they are necessary to
prevent your cat from becoming dehydrated (which for most cats occurs once
creatinine levels are consistently over 300 -350 (US: 3.5-4), then yes, your
cat will probably always need them. However, there are always exceptions. Some
cats may only need fluids to help them after a crisis (such as when they have
severe diarrhoea or vomiting which makes them dehydrated), for example,
particularly if they are young or if their bloodwork is normally reasonably
good.
If you do ever try to decrease or stop sub-Qs, it is very important to do this
slowly, because CKD kidneys cannot adjust to changes as easily as healthy
kidneys.
There are two main ways of giving sub-Qs, either via a giving set or via
syringe. Most people in the USA use the giving set method; people offered
sub-Qs in the UK (very uncommon) are usually offered the syringe method. For
those who struggle with needles, another possibility is to use an implanted
catheter.
Giving Set Method
The giving set method is similar in some ways to an IV drip, except that you
are placing the fluid under the skin rather than into a vein. You are also
giving a smaller amount of fluid more quickly. You will need fluids, needles
and venosets (IV sets). You use the venoset to connect the bag of fluid to the
needle which is then inserted under the skin. The fluid bag is hung high, so
gravity makes the fluid drip through the venoset and the needle and into the
cat.
There are more tips on how to prepare and give sub-Qs
here.
Syringe Method
With this method, you also inject the fluid under the skin, but instead of
using a venoset (a tube which carries the fluid from the fluid bag to the
needle), you remove the fluid from the fluid bag with a syringe, then attach
the needle to the syringe and place it under the skin. You then gently squeeze
the syringe so the fluid goes into the cat. This method means it is easier to
know how much fluid you are giving and is also usually quicker.
If
you use this method, you will need fluids, needles and syringes.
If, like me, you have a needle phobia, you will be feeling sick at the
mere idea. Yet I stuck a needle into Thomas twice a day for almost eight
months, and it honestly does get easier. I used to dread it in the early
days, far more than Thomas did; yet soon it became just part of everyday
life, like brushing teeth. We were used to it, he was used to it - it
took just ten minutes a day to give him his fluids and his medications.
Remember, you are doing this to help your
cat.
Cornell University College of Veterinary Medicine
has a video on how to give sub-Qs which states "This might be THE most
important thing that you can do at home to help your cat." If fluids are
necessary, they can make an amazing difference to how your cat feels -
it is like watering a plant in a drought and watching it bloom again.
Once you see the difference that fluids make, you should be able to find
the strength from somewhere. During the last twelve years I have heard
of literally thousands of people who have regularly given their cats
fluids; and I can only recall one person who was unable to overcome her
needle phobia (she did not even try to give sub-Qs). So read Sandi's
story below, check out the tips on how to give them
here, take a deep
breath and give it a go. If you'd like to have your hand held while you
get used to it, join
Tanya's CRF Support Group
Coco's
page gives tips and also advice on the emotional side of giving
sub-Qs.
Some people are put off the idea of giving sub-Qs because their vet
charges them a ridiculous amount for their supplies - the most expensive I
heard of was US52 for one bag of fluid! Quite outrageous when you know that people
in the US
and Canada people can buy supplies very cheaply, paying only US$16-40 for
an entire case of twelve bags! The
Obtaining Supplies Cheaply
page gives tips on where to find fluids and other sub-Q supplies at good
prices in the USA, UK and Canada.
Sandi and Maz -
Learning to Cope with Fluids
Here Sandi describes how she overcame her needle
phobia and successfully gave Maz his fluids before she lost him in October
2007.
"I know that some of you are really nervous/uneasy
about having to do SubQ's yourself, so I thought my story may help.
First, I have to say I am the world's biggest
needlephobic person (don't ask what's it's like when I need blood taken!). So
when Maz was diagnosed last October and I found out he had to be on Sub-Qs I
cried for a day, out of fear of doing SubQ's and also because I thought I was
losing Maz. Luckily a vet tech saw my tears and agreed to come to my house
three times a week (I paid her $45 including supplies).
This went on for about six months. During that time
though I would be the one to get Maz when she came over (he would always try
and
hide) and gently pet him while he was getting the fluids. I began to get used
to seeing the needle go in and also through this group started learning a
tremendous amount on making it more comfortable (warming etc). The tech
started telling me I knew as much as she did about giving fluids and Maz would
probably be more comfortable if I did it but I resisted, saying I just
couldn't stick my baby boy. Well, in April she got a new job and there wasn't
another vet tech who could come. So now, it would really be ALL UP TO ME! I
was petrified but with the help of the tech, I just did what I had to do. I
learned that heating the fluids made all the difference and that by giving Maz
some treats, other than the first needle poke, he forgets all about the fluids
and just likes getting treats (some Fancy Feast) and a lot of love. There are
times he even purrs now!
I have to admit, I still don't like poking him (I
take a minute or two to get myself psyched for it), then I gently let him know
I'm going to give him his treatment, take him into the bathroom where his
favorite towel and treats are waiting and go for it!
So please believe me when I say it's not as bad as
it seems, read the posts on the group and the info on Helen's website and you
will see in no time, you and your furbabies will be just fine!
If you really cannot bear giving sub-Qs, or if your cat really fights them,
you may want to consider whether to use an implantable tube. These products
are implanted in the cat under anaesthetic, and thereafter the fluids are
basically just poured in (though you should not give too much, of course).
The most commonly used tube in the USA is the Giftube.
This stands for Greta Implantable Fluid Tube and is named after the patient,
Greta, for whom the inventor created it. Having one fitted costs around
US$200-300. There is a similar product called the
Endo-Sof subcutaneous catheter (also known as the Cooks Catheter), which
tends to be offered in the UK.
It can be hard to get your vet to agree to you doing sub-Qs at home in the UK,
but if your vet does agree, it is sometimes on the basis of using one of these
products. This is not ideal because the infection rate for these products is
over 10%, which I find worrying. It is also extremely expensive, because a bag
of fluid can only be used for one sub-Q session before it is thrown away
(because of the risk of infection); plus many cats have to have two or more
tubes implanted each year because of problems with the previous tube
necessitating its removal. This is usually because the cat's body considers
the tube to be a foreign body and may form a kind of membrane around it, which
can prevent the fluids entering the cat's body smoothly. In addition, many
cats find the tube irritating and scratch at it constantly, so they often have
to wear a bandage or little sweater to hold the tube in place.
Therefore I would strongly recommend using standard
methods and only using these products as a last resort. If you do decide
to use one, please ensure your vet knows what s/he is doing: some people have discovered
after the tube has been implanted that their vet has never implanted one
before and their cat has basically been a guinea pig; I'd prefer to know that
beforehand and be sure that my vet could help me deal with any problems that
might arise.
There is another more recently introduced product called a Skin Button which
uses a mechanism called hypodermoclysis. The Skin Button is a small circle
similar in size to a coat button, and like a coat button, it has two parts,
one on the top and one on the underside. Unlike the other two products, this
can be placed with local anaesthetic rather than general anaesthetic. The skin
is supposed to grow around the button and reduce the risk of bacteria
entering. Unfortunately it carries similar risks of irritation to the Giftube
and Endo-Sof catheter, and can clog easily. It costs roughly US$100 plus your
vet's fee. It also requires the use of a special needle which increases the
cost.
Mar Vista Vet has information on all three
products, including photos of the skin button.
Norfolk Vet
Products also make a type of Skin Button. This site is currently
being remodelled and does not contain too much information.
Giftube
Users Forum - for people using the tube or contemplating its use.
This site is owned by Practivet and therefore puts a very positive spin on the
use of the tube.
Fluids are not
always acceptable treatment, and should only ever be administered with
veterinary approval.
Subcutaneous fluids should NOT be
administered to
your cat if any of the following criteria apply:
Your cat is so severely dehydrated that your vet
considers
intravenous fluid therapy (IV) more appropriate. In certain circumstances
IV
is the only correct treatment. If your cat
has high bloodwork levels (creatinine over 7), s/he might benefit more
from IV fluids initially, with sub-Qs provided once s/he returns home
as needed.
Your cat has a heart condition. Fluid therapy may
still be possible but your vet must decide if it is appropriate for
your cat, and determine the amounts and frequencies to be
administered.
Your vet has refused to agree to the procedure on
other medical grounds.
fluids from the previous session have not yet been
absorbed.
your cat is
over-hydrated. This may be obvious, or your cat may feel "squishy",
the way water in a plastic bag feels -
squishiness sometimes happens if a little air gets in with the fluids,
and is not normally a problem, but if it happens consistently, your cat may need less fluid. Other symptoms
of overhydration may include
sudden weight gain, coughing and nasal discharge. See
Symptoms
for more information. Overhydration
may be associated with a heart condition, but contrary to what some
vets claim it can still happen in a cat with a perfectly normal heart.
It is a good idea to
weigh
your cat regularly, to check for sudden or continous weight gain which
may give early warning of a problem; or
Processing the extra fluids in itself places an additional workload on the kidneys which can make the
CKD
progress faster; plus it can flush out
certain nutrients, and giving fluids when they are not needed may
increase blood pressure; so it is best not to
begin fluids until the advantages are likely to outweigh the
disadvantages. Dr Katherine James of the Veterinary Information Network believes
that most CKD cats will benefit from subcutaneous therapy once creatinine
levels are consistently over 300 -350 (US: 3.5-4). If your vet thinks your cat's
CKD is less advanced than this, then it is probably safer to hold off on
sub-Qs for the moment;
My vet agreed to us doing fluids in part because she
felt Thomas would not find them too distressing. You and your vet do
need to take your cat's personality into account in deciding whether to
go this route; but do not necessarily assume your cat cannot cope, many
cats who ordinarily hate medication of any kind tolerate sub-Qs because
they make them feel so much better. I would suggest trying them for a
few weeks at least.
Many cats
appear happier (more active and alert, with a better appetite) after
sub-Qs. However, some may become lethargic for an hour or so
afterwards. This is probably nothing to worry about, but if it happens
frequently it may be that your cat is not processing the fluid very
well, so I would ask your vet to check your cat for possible heart
problems or
fluid retention.
