Painkillers and Anti-Inflammatories – Tanya's Comprehensive Guide to Feline Chronic Kidney Disease

Overview

CKD is not considered to be a painful disease, so painkillers are a routine treatment for CKD cats.
However, sometimes a cat will need painkillers and/or anti-inflammatories, perhaps following surgery or to help with arthritis.

Table of Contents

When to Use

The need for painkillers may be a short- or long-term requirement, depending upon whether the problem is acute or chronic.

Examples of acute need:

acute pancreatitis
dental work or other surgeries
arterial thromboembolism (saddle thrombus or blood clot to the legs)

Examples of chronic need:

It is easier to stop pain developing rather than trying to control it once it has begun, so if for example your cat is about to have a dental, be sure to discuss pain control with your vet in advance.

If your cat is in pain, you must treat it.

Pain Assessment

Unfortunately it can be difficult to know when a cat is in pain. This is because firstly, cats instinctively try to hide the fact that they are in pain; and secondly, some of the signs of pain in cats are different to what you might expect, e.g. purring, restlessness. Other possible signs include growling, avoiding interactions, sleeping a lot or sitting in a hunched position.

WSAVA guidelines for recognition, assessment and treatment of pain (2014) Mathews K, Kronen PW, Lascelles D, Nolan A, Robertson S, Steagall PVM, Wright B & Yamashita K Journal of Small Animal Practice 55(6) ppE10–E68 state “We cannot always know that our patient does hurt, but we can do our best to ensure that it does not hurt.”

Please see Symptoms for more information on the signs of pain in cats, including information on the Grimace Scale.

Choices

Many painkillers which work well for dogs and humans are not tested on cats and therefore not approved for use in cats. Therefore most of the products discussed below are used off-label in cats.

It is wise to consider the use of additional treatments, such as nutraceuticals and/or acupuncture for arthritic cats and anti-nausea medications for cats with pancreatitis. This may enable you to lower the dose of the painkillers you are using. WSAVA guidelines for recognition, assessment and treatment of pain (2014) Mathews K, Kronen PW, Lascelles D, Nolan A, Robertson S, Steagall PVM, Wright B & Yamashita K Journal of Small Animal Practice 55(6) ppE10–E68 say “The authors recommend that particularly in all chronic pain patients, non-drug treatment modalities should be used alongside pharmaceutical treatments.”

Newer options for chronic pain management (2011) Stein B Veterinary Anesthesia and Analgesia Support Group also discussed the various painkillers available.

This section covers a number of painkillers which tend to be used in cats, as follows:

Opiates

buprenorphine (Buprenex, Vetergesic)
fentanyl
tramadol

Non-steroidal anti-inflammatory drugs (NSAIDs)

meloxicam (Metacam, Meloxidyl)
robenacoxib (Onsior)

Other painkillers

frenevetmab (Solensia)
gabapentin

Opiates

Opiates are narcotics, which means they belong to the same drug family as morphine. These drugs are derived from the poppy and are the most powerful painkillers. 2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 say “opioids are the most effective drug class for managing acute pain and can play a role in managing chronic pain.”

Opioid therapy (2011) Thompson D Veterinary Anesthesia and Analgesia Support Group has an overview of opiates.

Buprenorphine (Buprenex, Vetergesic, Temgesic)

Buprenorphine, sometimes colloquially referred to as bupe, is a narcotic which is thirty times more potent than morphine. Trade names include Buprenex (USA), Vetergesic (UK) and Temgesic (UK and Australasia). Because it is such a powerful opioid, buprenorphine is a controlled substance in most countries.

Buprenorphine is a popular choice for cats because it works promptly and effectively, lasts for 6-8 hours (longer in some formulations), and has relatively few side effects.

Mar Vista Vet has an overview of buprenorphine.

Pet Place also has some information about buprenorphine.

Buprenorphine (2015) Claude A Clinician’s Brief Jun 2015 pp31-32 explains more about buprenorphine.

Buprenorphine Formulations and Administration

Buprenorphine is available in an injectable form which, rather confusingly, may be administered intravenously, intramuscularly, subcutaneously or transmucosally.

The intravenous and intramuscular methods of administration are normally only used in a clinic setting.

For home use, your options are therefore transmucosal application (oral) or subcutaneous injection.

Buprenorphine: Transmucosal (OTM or Intrabuccal)

Buprenorphine should not be given orally (as in, swallowed) because it is ineffective when given in such a way.

However, it is often given in transmucosal (intrabuccal) form, i.e. it is placed in the mouth (usually by being squirted from a syringe) between the cheek and the gum. When applied to the mucus membranes in this way, it can be easily and quickly absorbed by the body, within around 30 minutes, with its effects lasting for around eight hours.

Systemic update of buprenorphine by cats after oral mucosal administration (2003) Robertson SA, Taylor PM & Sear JW Veterinary Record 152(22) pp675-8 found that administering buprenorphine via the oral mucosal route was as effective as injecting it, and the majority of owners preferred this method of administration.

A review of the studies using buprenorphine in cats (2014) Steagall PVM, Monteiro-Steagall BP & Taylor PM Journal of Veterinary Internal Medicine 28 pp762-70 says “At clinical dosages… the buccal route has produced inconsistent results.” However, WSAVA guidelines for recognition, assessment and treatment of pain (2014) Mathews K, Kronen PW, Lascelles D, Nolan A, Robertson S, Steagall PVM, Wright B & Yamashita K Journal of Small Animal Practice 55(6) ppE10–E68 say “buprenorphine given by the oral transmucosal route has been demonstrated to produce effective antinociception [pain blocking] in cats”, and 2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 say “The oral transmucosal or buccal route of administration for buprenorphine may have clinical efficacy as well.” Certainly many members of Tanya’s CKD Support Group find it seems to work well for their cats.

The buprenorphine used for this purpose is the standard (not the extended release versions) injectable form of buprenorphine.

It is flavourless so most cats tolerate this well.

Buprenorphine Subcutaneous

Subcutaneous buprenorphine has long been considered to be ineffective at standard (0.02mg/kg) doses. A review of the studies using buprenorphine in cats (2014) Steagall PVM, Monteiro-Steagall BP & Taylor PM Journal of Veterinary Internal Medicine 28 pp762-70 says “At clinical dosages, the SC route of administration does not appear to provide adequate antinociception and analgesia.” 2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 say “in cats, the subcutaneous (SC) route of opioid administration is not recommended.”

Increasing the doses would not necessarily make buprenorphine work more effectively, because it is known for having a “ceiling effect.” Mar Vista Vet explains “While buprenorphine is commonly dispensed for three times daily usage, how long a dose lasts actually depends on the size of the dose. This is possible because of buprenorphine’s “ceiling effect” which means that once a maximum effect has been reached (i.e. all the receptors have been bound with drug), giving more buprenorphine does not create a greater effect. Instead, the higher the dose, the longer the effects last.”

Recent research indicates that giving more concentrated doses subcutaneously may actually provide effective pain relief for longer periods without adverse effects. Pharmacokinetic and pharmacodynamic evaluation of high doses of buprenorphine delivered via high-concentration formulations in cats (2016) Taylor PM, Luangdilok CH & Sear JW Journal of Feline Medicine and Surgery 18(4) pp290-302 looked at the effectiveness of buprenorphine given subcutaneously to healthy cats. The study found that higher doses lasted for over 24 hours, sometimes close to 48 hours. The study concludes “0.12 and 0.24 mg/kg doses of aqueous buprenorphine given subcutaneously appear to provide at least 24 h antinociception with no side effects other than mydriasis [dilated pupils].”

Newer formulations have been released as follows:

Simbadol

Simbadol is a form of buprenorphine which is given by subcutaneous injection and which is said to last for 24 hours, so it only needs to be given once a day.

Pharmacokinetic and pharmacodynamic modelling after subcutaneous, intravenous and buccal administration of a high-concentration formulation of buprenorphine in conscious cats (2017) Doodnaught GM, Monteiro BP, Benito J, Edge D, Beaudry F, Pelligand L & Steagall P PLoS ONE 12(4) e0176443 looked at Simbadol and concluded “The SC administration of Simbadol was characterized by prolonged absorption half-life and sustained plasma concentrations yielding long-lasting antinociception (24 hours) when compared with the IV and OTM routes.”

Drugs mentions that two cats died during trials of Simbadol because of apnoea (stopping breathing). The trials involved 450 cats, all of whom underwent surgery. One of the cats had undiagnosed cancer, the other had no obvious health problems. Most CKD cats receive buprenorphine while conscious rather than during surgery.

Buprenorphine SR

Buprenorphine SR is a sustained release form of buprenorphine which is given by subcutaneous injection and which is supposed to last for 72 hours.

Buprenorphine Dosage

The doses given below are commonly used in cats. However, A review of the studies using buprenorphine in cats (2014) Steagall PVM, Monteiro-Steagall BP & Taylor PM Journal of Veterinary Internal Medicine 28 pp762-70 says “Cats may have great individual variability with respect to the number, morphology, and distribution of opioid receptors relative to other species…, so buprenorphine may not provide sufficient analgesia in some cats, and it may be very effective in others. Analgesic protocols should be tailored to the individual patient.”

Transmucosal

The usual dose is 0.01-0.03 mg/kg, which is given up to three times a day. Here is a table showing what this means for cats of different weights:

Cat Weight	Dosage in mg
	0.01 mg/kg dose	0.02 mg/kg dose	0.03 mg/kg dose
5 lb (2.27kg)	0.0227	0.0454	0.068
8 lb (3.64kg)	0.0364	0.0728	0.109
10 lb (4.5kg)	0.0450	0.0901	0.135

Injectable buprenorphine (which is what you will probably be using, but applying to the cheek) is available in a number of different strengths. Since these are tricky amounts to calculate, many vets provide small syringes containing the correct dose and you just gently squeeze the contents into your cat’s mouth towards the cheek.

Subcutaneous

The usual dosage of Simbadol (1.8 mg/mL) is 0.24 mg/kg (0.11 mg/lb) administered subcutaneously once daily, for up to 3 days.

Buprenorphine Sources

Buprenorphine is available in vials (not usually offered to clients in the USA) or small prefilled syringes, each containing about 1ml of buprenorphine. These contain injectable buprenorphine, but it is safe to give this by squirting the contents of the syringe into the cheek as long as it is not the sustained release version.

Since the introduction of sustained release buprenorphine, some vets are no longer supplying syringes to clients for home use (since buprenorphine is a controlled drug), and instead are only prepared to administer the subcutaneous sustained release injectable version in their office. This would require two trips to the vet each week, which is not ideal for most people or cats.

Some people prefer to obtain oral suspension buprenorphine instead.

USA

Diamondback Drugs

This compounding pharmacy is used by many members of Tanya’s CKD Support Group for buprenorphine. It offers an oral suspension made from a powder mixed with preserved water which you can then apply to your cat’s cheek inside the mouth.

The strength dispensed is typically 0.3mg/ml. It will dispense the product as directed by your vet, but the price is the same for any amount up to 30 mls, which is good for up to 180 days.

The price as at January 2019 was US$40 for a bottle up to 30 ml in size plus US$8 flat rate shipping.

You will also need syringes to draw up and give the medication.

Diamondback also compound an injectable form in an 0.6 mg/ml strength which comes in a 10 ml vial, but this is probably too high a strength for most cats, plus it contains a preservative which may sting.

Wedgewood Pharmacy

This compounding pharmacy charges around US$50 (June 2020) for 15ml of a 0.3mg/ml strength product. The link is for 0.6mg/ml strength, but I understand they will do the lower strength upon request.

UK

In the UK you will often be offered buprenorphine for home use in 5ml or 1ml vials. Although the 5ml and 10ml vials tend to be cheaper, it is better to buy the 1ml vials because there is a preservative added to the larger size vials which gives the medication an unpleasant taste.

Buprecare is one possible brand, which is available in a 0.3mg/ml strength. This product does not contain a preservative.

VioVet

Sells buprenorphine with a prescription for £17.50 for five 1mg vials of the 0.3mg/ml strength.

Buprenorphine Side Effects

The most common side effect is sedation. This may improve as the cat’s body gets used to the medication.

You may see dilated pupils (mydriasis). Pharmacokinetic and pharmacodynamic evaluation of high doses of buprenorphine delivered via high-concentration formulations in cats (2016) Taylor PM, Luangdilok CH & Sear JW Journal of Feline Medicine and Surgery 18(4) pp290-302 says “there were no adverse effects other than mild mydriasis, which is usually seen in cats treated with buprenorphine at low doses anyway.”

Buprenorphine makes some cats purr more and become very affectionate, whilst other cats become restless.

The main concern is respiratory depression, which may be seen as slowed breathing and/or shallower breathing. However, Plumb’s Veterinary Drugs Handbook (7th Ed.) says this is rare, though it advises that buprenorphine “should be used cautiously in patients with compromised cardiopulmonary function.”

Buprenorphine is cleared by the liver so it tends to be a good choice for CKD cats who need ongoing pain control. However, cats with CKD may eliminate it more slowly. Plumb’s Veterinary Drugs Handbook says “All opiates should be used with caution in patients with… severe renal insufficiency… and in geriatric or severely debilitated patients.” Discuss with your vet whether to lower the dose.

Virtually everybody I’ve heard from has found buprenorphine extremely effective with few side effects.

Buprenorphine Interactions

Be careful if you are using buprenorphine with cyproheptadine (an appetite stimulant) because using both together may result in an increased sedative effect.

Drugs mentions that the risk of respiratory depression is increased if buprenorphine is used concomitantly with gabapentin.

Fentanyl (Duragesic)

Fentanyl is a narcotic belonging to the same drug family (opioids) as buprenorphine and morphine. Therefore it is a very effective painkiller.

Mar Vista Vet has some information about Fentanyl.

Fentanyl Formulations

Fentanyl is usually given in the form of a patch (like a plaster) on the skin which slowly releases the medication for 4-5 days.

My Indie (non-CKD) had extensive dental extractions, and was given a fentanyl patch to help her oral pain. The patch was applied to a small area of shaved skin on one of her back legs, and lasted for several days. It worked very well for her, she was a little subdued but that was the only side effect (which might actually have been due to the after effects of the surgery). However, up to a third of cats absorb less of the medication than is needed for effective pain control, so be aware of the signs of pain in cats so you can ensure it is working properly for your cat.

Fentanyl Side Effects

Side effects are uncommon and usually minor e.g. allergy to the patch adhesive.

The most common serious side effect (although it is still relatively rare) is an adverse effect on breathing, which may manifest itself as lethargy. Fortunately removing the patch should quickly resolve any problems.

Care should be taken to ensure that the cat cannot remove the patch or lick it.

Fentanyl Interactions

Fentanyl should not be used in cats taking selegiline (Anipryl) for cognitive dysfunction.

Heat can increase the amount of fentanyl released, which could be very dangerous, so access to heat (e.g. heated cat beds) should be removed for any cat with a fentanyl patch.

Tramadol (Ultram)

Strictly speaking tramadol is not an opiate but it has some effect on opioid receptors, so I am including it in this category.

Pain medicine: Tramadol Moses L Angell Animal Medical Center explains that response to tramadol varies from patient to patient, and that it may be better to use it in conjunction with other pain control methods. Fortunately it can be used safely in conjunction with a number of other medications. Mar Vista Vet says “The beauty of tramadol as a pain reliever is that it is compatible with all the COX-inhibiting non-steroidal anti-inflammatory drugs, possibly even synergizing with them. The same is true with tramadol combined with gabapentin and amantidine. It is also compatible with joint pain nutriceuticals such as glucosamine, MSM, chondroitin sulfate etc.”

Wedgewood Pharmacy gives an overview of Tramadol.

Tramadol Formulations

Tramadol is available in tablet and liquid form in a variety of sizes, but the 50mg tablets are often used in cats.

Tramadol is available as a generic which means it is inexpensive.

Unfortunately, tramadol tastes very bitter to cats, so it is wise to give it in a gelcap.

Tramadol Dosage

Tramadol is dosed at 1 to 2 mg/kg 2-3 times a day, so a 10 lb (4.5kg) cat would receive 4.5 – 9mg 2-3 times a day.

In practice many people simply start with a quarter of a 50mg tablet (12.5mg) twice a day, but of course be guided by your vet.

Tramadol is metabolised largely by the liver but around 30% is excreted by the kidneys so your vet may wish to reduce the dose for a CKD cat.

Mar Vista Vet mentions that if tramadol is used longer term, it should be tapered off rather than stopped suddenly.

Tramadol Side Effects

Tramadol is a safe treatment when used at appropriate dosage levels and side effects are rare, but include sedation, loss of appetite, vomiting and constipation. Dilated pupils may also be seen in cats.

Tramadol has been known to cause hallucinations and seizures in humans so should be used with caution in cats with a history of seizures.

Tramadol Interactions

Ondansetron inhibits the analgesic effects of tramadol: a possible 5-HT3 spinal receptor involvement in acute pain in humans (2002) Arcioni R, della Rocca M, Romano S, Romano R, Pietropaoli P & Gasparetto A Anesthesia and Analgesia 94(6) pp1553-7 reports that ondansetron (commonly used for nausea in CKD cats) may reduce the painkilling effects of tramadol by up to 50% in humans.

Be careful if you are using tramadol at the same time as cyproheptadine (an appetite stimulant) because using both together may reduce the effectiveness of the tramadol.

Mar Vista Vet mentions that using tramadol at the same time as another appetite stimulant called mirtazapine may increase the risk of serotonin syndrome.

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)

Non-steroidal anti-inflammatory drugs help to reduce inflammation and may offer some degree of pain control. The NSAIDs most commonly used in cats are meloxicam and robenacoxib (these are discussed below).

ISFM and AAFP consensus guidelines: long-term use of NSAIDs in cats (2010) Sparkes AH, Heiene R, Lascelles BDX, Malik R, Real Sampietro L, Robertson S, Scherk M & Taylor P Journal of Feline Medicine and Surgery 12 pp521-538 provide guidelines for their use. The guidelines are also available in French, German, Japanese and Spanish here.

Non-Steroidal Anti-Inflammatory Drugs: Mechanism

NSAIDs work by blocking prostaglandin production. They do this by binding with enzymes called cyclo-oxygenase (CoX).

There are two forms of CoX:

CoX-1 is protective, particularly in the kidneys and the digestive tract.
CoX-2 produces pain and inflammation.
Therefore the goal is usually to reduce levels of CoX-2 whilst not affecting CoX-1.

Reducing levels of CoX-2 only does not entirely remove the risk of side effects. 2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 say “Studies indicate that NSAiDs that spare cyclooxygenase (CoX)-1 produce a lower frequency of Gi lesions.” However, the guidelines also say “the more highly CoX-2selective inhibitors may actually produce more adverse events when underlying gastric damage is already present.”

Non-Steroidal Anti-Inflammatory Drugs: Advantages

Most NSAIDs used in cats are relatively cheap and very effective. They are usually supplied in formulations that are easy to give too.

Because they are anti-inflammatory, NSAIDs can be very helpful, especially for chronic conditions such as arthritis. 2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 say “The majority of conditions that cause pain have an inflammatory component. Non-steroidal anti-inflammatory drugs (NSAiDs) are a mainstay for management of chronic pain as well as for perioperative use.”

As regards safety, they also state “NSAiDs should be used for their central and peripheral effects in both dogs and cats after consideration of risk factors. There is no indication that any one of the veterinary-approved NSAiDs is associated with any greater or lesser incidence or prevalence of adverse events.”

Non-Steroidal Anti-Inflammatory Drugs: Disadvantages

Unfortunately cats tend to metabolise NSAIDs poorly, so historically many vets have been reluctant to use these medications in cats because of the risk of side effects. Pet Poison Helpline explains more about the risks of using NSAIDs and what warning signs to watch for.

2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 state “of the adverse events associated with NSAiDs, gastrointestinal (Gi) toxicity is the most common. In cats, inappetence appears to be the most common adverse event.” It also says “Although the overall incidence and prevalence of NSAiD-related toxicity is unknown, it does appear to be very low relative to the number of doses administered.”

Research indicates that NSAIDs are usually safe for short-term use in healthy cats when used appropriately. Effects of non-steroidal anti-inflammatory drugs (NSAIDs) on renal function (2007) Brown SA State of the Art in Renal Disease in Dogs and Cats Proceedings, Vetoquinol Academia reports (page 31) on the use of NSAIDs in CKD. Dr Brown states “It has long been known that NSAIDs have a good margin of renal safety for short- term use in healthy animals.”

See below for more information on the use of NSAIDs in cats with CKD.

NSAIDS should not be used at the same time as corticosteroids.

Close monitoring is required if NSAIDs are used in cats taking ACE inhibitors such as benazepril or diuretics because using these treatments together increases the risk of kidney problems.

Non-Steroidal Anti-Inflammatory Drugs: Use in CKD Cats

Some vets do not like using NSAIDs in CKD cats, while others feel they are can be safely used in certain circumstances.

Many cats require NSAIDs longer-term, e.g. to treat arthritis. Although some oral NSAIDS are approved for use longer-term in cats in some countries, caution is still advised for cats with certain problems such as CKD. 2015 AAHA/AAFP pain management guidelines for dogs and cats (2015) Epstein ME, Rodan I, Griffenhagen G, Kadrlik J, Petty MC, Robertson SA & Simpson W Journal of Feline Medicine and Surgery 17 pp251–272 say “Be cautious or avoid NSAIDs in patients with the following existing/anticipated conditions:

“Low-flow states such as dehydration, hypovolemia, congestive heart failure and hypotension.
Renal, cardiac or hepatic dysfunction.”

Long-term use of non-steroidal anti-inflammatory drugs in cats with chronic kidney disease: from controversy to optimism (2019) Monteiro B, Steagall PVM, Lascelles BDX, Robertson S, Murrell JC, Kronen PW, Wright B & Yamashita K Journal of Small Animal Practice 60(8) pp459-462 says “not all CKD cats are good candidates for long-term NSAID administration.” The paper says NSAIDs should only be used in CKD cats:

who are stable, with few changes in weight or creatinine for at least two months, and with other problems such as hypertension under control
ideally in IRIS stage 1 or 2, and possibly 3 in some circumstances
well hydrated
at the lowest effective dose
with phosphorus levels kept under control
with regular ongoing monitoring, including by the caregiver
in conjunction with other pain management techniques, such as acupuncture

The study concludes “based on current evidence, the WSAVA-GPC [World Small Animal Veterinary Association-Global Pain Council] supports the long-term administration of the lowest effective doses of meloxicam and robenacoxib in cats with concomitant chronic pain and CKD as part of a multimodal approach that includes non-pharmacological therapies, unless contraindicated.”

Meloxicam and robenacoxib in cats with chronic kidney disease (2020) Wood MW Clinician’s Brief May 2020 pp43-44 discusses this and other studies.

Meloxicam (Metacam or Meloxidyl)

Meloxicam is a non-steroidal anti-inflammatory drug that may be used in cats for acute or chronic pain.

Meloxicam is a CoX-2 preferential NSAID, i.e. it works effectively on CoX-2 to reduce pain and inflammation, but it also reduces levels of CoX-1 to some degree. See above for more about this.

Pet Place has some information about meloxicam.

Mar Vista Vet also has some information about meloxicam.

Meloxicam Formulations and Usage

Meloxicam is available in both injectable and oral (liquid) form, as follows:

USA

Only approved (under the trade name of Metacam) for use in cats in the injectable form.
Intended to be a one-off treatment as a painkilling injection following surgery.
A canine oral version is available which is sometimes used off-label in cats.

Europe

The injectable form is approved for one-off use in cats following surgery, the same as in the USA.
An oral form was licensed in 2007 for use in cats for longer term pain management e.g. in cats with arthritis, under the trade name of Metacam.
Another oral form was licensed in 2011 for use in cats for longer term pain management e.g. in cats with arthritis, under the trade name of Meloxidyl.

Meloxicam Risks and Benefits

Many people are frightened to use meloxicam in their cats, particularly in cats with CKD. This is largely because a Freedom of Information Summary (2004) US Food and Drug Administration stated (page 23) that, following the use of Metacam for post-operative pain, 8.3% of the cats in the study had elevated BUN levels, and 12.5% had anaemia (anaemia is common in cases of inflammation, which may partly explain this finding, since meloxicam is an anti-inflammatory medication). The paper concludes: “Meloxicam, when initially dosed as a subcutaneous injection followed by oral dosing for nine days at > 0.3 mg/kg was associated with severe adverse effects, including death.”

This was followed in October 2010 by the Food and Drug Administration announcing that a “black box warning” would be added to meloxicam. The black box warning states: “Warning. Repeated use of meloxicam in cats has been associated with acute renal failure and death. Do not administer additional injectable or oral meloxicam to cats. See contraindications, warnings and precautions for detailed information.”

Other countries take a different view of meloxicam, as shown by their approval of oral versions of meloxicam for longer term use in cats. In fact, research since the black box warning was issued in 2010 indicates that meloxicam can be safe for healthy cats, and even for CKD cats as long as safety guidelines are followed.

Effects of meloxicam on plasma iohexol clearance as a marker of glomerular filtration rate in conscious healthy cats (2009) Goodman LA, Brown SA, Torres BT, Reynolds LR & Budsberg SC American Journal of Veterinary Research 70(7) pp826-30 checked the glomerular filtration rate (a measure of kidney function) in six healthy cats before and after short-term administration of meloxicam and did not find any deterioration.

Subsequent studies looked at the longer term use of meloxicam. Long-term safety, efficacy and palatability of oral meloxicam at 0.01-0.03mg/kg for treatment of osteoarthritic pain in cats (2008) Gunew MN, Menrath VH, Marshall RD Journal of Feline Medicine & Surgery 10(3) pp235-41 monitored forty cats who were given meloxicam for arthritis for almost six months, three of whom had pre-existing renal disease. The study found that “no deleterious effect on renal function was detected in cats studied.”

Retrospective case-control study of the effects of long-term dosing with meloxicam on renal function in aged cats with degenerative joint disease (2011) Gowan RA, Lingard AE, Johnston L, Stansen W, Brown SA, Malik R Journal of Feline Medicine & Surgery 13(10) pp752-761 retrospectively examined the records of a veterinary practice over a five year period and concluded that “long-term therapy with meloxicam at a median dose of 0.02 mg/kg/day can be administered safely to aged cats with CKD, provided they are clinically stable. The results further suggest that meloxicam may actually slow the progression of renal disease in cats with both DJD and CKD by direct or indirect mechanisms.” The study goes on to speculate that meloxicam might slow the progression of CKD by reducing proteinuria (studies indicate that medications in the same family as meloxicam can reduce proteinuria in humans and rats).

A retrospective analysis of the effects of meloxicam on the longevity of aged cats with and without overt chronic kidney disease (2012) Gowan RA, Baral RM, Lingard AE, Catt MJ, Stansen W, Johnston L & Malik R Journal of Feline Medicine and Surgery 14(12) pp876-81 looked into the use of meloxicam in cats with CKD. This study examined the records of 82 cats over the age of seven who had been given meloxicam for six months or longer. 47 of the cats were known to have CKD, the other 35 showed no obvious signs of CKD. The most common cause of death in both groups was cancer, not CKD. The study concluded “the survival data presented here confirm that many cats with carefully managed CKD can survive for a substantial period with standard medical therapy. In addition, long-term treatment with oral meloxicam did not appear to reduce the lifespan of cats with pre-existent stable CKD, even for cats in IRIS stages II and III.”

Meloxicam can be very helpful for cats with arthritis. There is more information about using it in cats with arthritis here.

Meloxicam Dosing

The dosage used appears to be critical when it comes to benefiting from meloxicam whilst reducing the risk of any problems.

It is also important not to use oral meloxicam after injectable meloxicam. I know many vets do offer oral meloxicam following the use of injectable meloxicam during surgery such as spaying, but it should be noted that the manufacturer says “Metacam 0.5 mg/mL Oral Suspension for Cats should not be used following parenteral injection of meloxicam or any other NSAID as appropriate dosage regimens for such follow-up treatments have not been established.”

Meloxicam Dosing: Healthy Cats

For healthy cats, the dose of the oral medication recommended by one manufacturer for the treatment of chronic pain in cats is:

a single oral dose of 0.1 mg meloxicam/kg body weight on the first day.
a maintenance dose of 0.05 mg meloxicam/kg body weight once daily thereafter at 24 hour intervals.
“For longer term treatment, once clinical response has been observed (within 7 days), the dose of Metacam can be adjusted to the lowest effective individual dose reflecting that the degree of pain and inflammation associated with chronic musculoskeletal disorders may vary over time.”

Adverse reactions to meloxicam have been reported much more frequently in the USA than in countries where oral meloxicam is approved for longer term use in cats. This may be because those countries provide vets with guidelines on suitable doses for cats, which is not the case in the USA.

The fact that the USA has not approved a feline formulation may actually be contributing to the problem, because vets in the USA who wish to prescribe meloxicam off-label for a feline patient have to prescribe the canine version, which is three times as strong as the feline version available in other countries. Vets should of course be reducing the dose for their feline patients, but since meloxicam is often dosed in drops rather than precise measurements, it may be that they are instructing their clients to give it in drops (Metacam comes with a dropper dispenser) directly into the cat’s mouth rather than measuring it out in mg first, and thus not adjusting the dose appropriately and safely for cats.

If your cat develops kidney problems following the use of meloxicam, please see below for information on how best to treat it, and how to report it to the authorities.

Meloxicam Dosing: CKD Cats

If you wish to use meloxicam in a CKD cat, one option is to give half of the dose that you would give to a healthy cat of the same weight and see if it helps your cat. Retrospective case-control study of the effects of long-term dosing with meloxicam on renal function in aged cats with degenerative joint disease (2011) Gowan RA, Lingard AE, Johnston L, Stansen W, Brown SA, Malik R Journal of Feline Medicine & Surgery 13(10) pp752-761 retrospectively examined the records of a veterinary practice over a five year period and concluded that “long-term therapy with meloxicam at a median dose of 0.02 mg/kg/day can be administered safely to aged cats with CKD, provided they are clinically stable.”

Please note the study refers to cats with stable CKD. If your cat has recently crashed, or is dehydrated or is not eating, meloxicam is unlikely to be suitable. The study also says “Adverse effects on the kidney occur when NSAIDs are used in cats that are dehydrated, hypovolaemic or hypotensive, but meloxicam is not of itself nephrotoxic, and there is evidence that for cats with stable CKD and chronic pain, use of low dose meloxicam can achieve improved survival and maintenance of bodyweight with no acceleration of renal deterioration.”

ISFM and AAFP consensus guidelines: long-term use of NSAIDs in cats (2010) Sparkes AH, Heiene R, Lascelles BDX, Malik R, Real Sampietro L, Robertson S, Scherk M & Taylor P Journal of Feline Medicine and Surgery 12 pp521-538 has a box on page 530 which explains the precautions that should be taken when using NSAIDs in cats with renal disease.

https://pubmed.ncbi.nlm.nih.gov/32594827

Effects of low dose meloxicam in CKD cats

Meloxicam: Whether To Use

Some people refuse to use meloxicam for any of their cats, healthy or otherwise, preferring to rely on other medications, usually painkillers.

I do not personally view meloxicam as a last resort treatment. Yes, there are other treatments available for pain control in cats, but meloxicam is anti-inflammatory, whereas most of the alternatives are simply painkillers. Meloxicam is also easy to give, very effective and reasonably priced.

I would definitely consider using meloxicam for a cat whose kidneys appeared fine in tests and who would benefit from it, such as my arthritic Karma. In fact, I wish I had started Karma on it far sooner than I did. Buying into the fear of using NSAIDs in cats, I did not start giving non-CKD Karma meloxicam until she was already sixteen years old and had had arthritis for some years. I am still kicking myself for not giving it to her sooner, because the difference was like night and day: she was just so much happier and more active once her pain was under control.

We also used meloxicam for Harpsie when his arthritis flared up acutely following a fall off a sofa while we were out and he was in dreadful pain which other medications did not seem to help (he was literally screaming). It worked very well and caused no long term problems for him, but since Harpsie had PKD, we only used it at a very low dose, and much less frequently than normally recommended, and it still controlled the pain effectively. We checked his kidney values a month later (they were fine).

If either of them had had CKD, I would still have considered using it (at very carefully dosed levels with regular monitoring), bearing in mind that controlling pain is more important for quality of life than anything else. It may be better for me to keep my cats around for as long as possible, but I am not convinced that it is better for my cats to live a longer but pain-filled life.

Meloxicam Interactions

Close monitoring is required if NSAIDs are used in cats taking ACE inhibitors (such as benazepril or enalapril) or diuretics because using these treatments together increases the risk of kidney problems.

Do not use meloxicam at the same time as corticosteroids.

Development of an injection site sarcoma shortly after meloxicam in an unvaccinated cat (2011) Munday JS, Banyay K, Aberdein D, French AF Journal of Feline Medicine & Surgery 13(12) pp988-91 reports on a cat who developed sarcoma (a form of cancer) where meloxicam was injected. This is extremely rare.

Meloxicam: Dealing with Adverse Reactions

Most cats who develop kidney problems after using meloxicam are suffering from acute kidney injury (AKI). Therefore their kidney values in blood tests may be extremely high, with creatinine often in the high teens.

A treatment programme which includes 4-5 days of IV fluid therapy (hospitalisation), followed by 4-6 weeks of sub-Q fluids at home, is often recommended by the manufacturers, but talk to them (see below) and see what they suggest for your cat.

I would also suggest that you ask the manufacturers to pay your veterinary costs — I know they have done this for some people, although they have not necessarily paid the full costs. It would appear that they may pay more if your vet calls.

Do not give up hope! Acute kidney injury is difficult to treat, but not impossible: an aggressive treatment plan should see those numbers dramatically reduce in most cases, and in some cases a complete recovery from a case of acute kidney injury is possible. In fact, one person was told by the manufacturer of Metacam that 77% of cats affected by meloxicam make a full recovery with prompt and proper treatment, so don’t opt for euthanasia immediately.

However, I understand that the manufacturer considers a creatinine in the 3 mg/dl range to indicate that the cat is stabilised, and whilst this is certainly not a critical level nor grounds for euthanasia, it does indicate some residual kidney damage.

Meloxicam: Reporting Adverse Reactions

If you believe your cat has developed kidney disease as a result of using meloxicam, you should report this as follows:

USA

If you have used Metacam, contact the manufacturer on 1-866-METACAM (638-2226). You may find yourself speaking to a Dr Carey or a Dr Grubb, but whoever you talk to should be able to work with your vet to devise a treatment plan.

You should also make a report to the Food & Drug Administration. Apparently the manufacturers are not obliged to report any cases of kidney problems to the FDA because renal failure is already listed in the package insert as a possible side effect, but I believe it is very important for the FDA to be fully aware of the scale of the problem. FDA Consumer Complaints Co-ordinator has details of the relevant contacts for each state (at the bottom of the page).

Canada

The manufacturer’s contact number is 1-800-325-9167, though they will only speak to vets.

You should also report it to the Veterinary Drugs Directorate.

UK

You should report it to the Veterinary Medicines Directorate.

Meloxicam Research

There is interest in using meloxicam for reasons other than pain control, as follows:

Slowing the Progression of CKD

In light of the studies mentioned above, which seemed to indicate that meloxicam might slow the progression of CKD in cats, a study has recently closed at the University of Kansas Veterinary Health Center. Results should be available in due course.

Cancer, Particularly Squamous Cell Carcinoma (SCC)

There is some evidence that meloxicam may help cats with certain cancers, including oral squamous cell carcinoma, a cancer that can be very difficult to treat. A review of feline oral squamous cell carcinoma (2016) Pellin M & Turek M Today’s Veterinary Practice Nov/Dec 2016 pp24-33 says “use of COX-inhibiting anti-inflammatory medications may have several beneficial effects in cats with SCC, including:

Pain relief
Reduction of neoplasia-associated inflammation and edema
Potentially, anticancer effects, such as disease response or stabilization.”

Robenacoxib (Onsior)

Robenacoxib is a non-steroidal anti-inflammatory drug (NSAID). It is somewhat different to meloxicam in that it is a CoX-2 selective NSAID, i.e. it works effectively on CoX-2 to reduce pain and inflammation but does not affect levels of CoX-1. See above for more about this.

Mar Vista Vet has some information about robenacoxib.

Robenacoxib Formulations and Usage

Robenacoxib is only approved for short-term use in cats. You may be offered it if your cat undergoes surgery or has a serious arthritis flare up.

There is more information about using robenacoxib in cats with arthritis here.

USA

Approved since 2011 for use in cats to control post-operative pain and inflammation.
Can be used once daily for up to three days.

Onsior is the manufacturer’s US website.

Approved since 2009 for use in cats for the treatment of acute pain and inflammation associated with musculoskeletal disorders (e.g. arthritis).
Can be used for up to six days.

The National Office of Animal Health in the UK has some information about Onsior.

Robenacoxib Dosage

Doses should be administered approximately 30 minutes before surgery.

Robenacoxib should not be used in cats weighing less than 2.5kg (5.5lbs).

USA

Tablets

1 mg/kg (0.45 mg/lb) orally once daily for up to a maximum of 3 days. Use the lowest effective dose for the shortest time necessary to obtain the necessary effect for the individual.

Injection

2 mg/kg (0.91 mg/lb) subcutaneously once daily for up to a maximum of 3 days. Subsequent doses can be given via subcutaneous injection or interchanged with oral tablets.

Tablets

1 mg/kg (0.45 mg/lb) (but with a range of 1-2.4mg/kg) orally once every 24 hours for up to a maximum of 6 days for musculoskeletal disorders.
A single oral treatment may also be given prior to orthopaedic surgery, and once daily treatment may be continued for two further days

Injection

2 mg/kg (0.91 mg/lb) subcutaneously given 30 minutes before surgery. After this, once daily treatment may be continued at the same time every day for up to two days

Robenacoxib Side Effects

According to the manufacturer, a number of studies were conducted on robenacoxib in cats, including a 21-day, 42-day and six-month study at up to 10 times the daily dose approved for use. Side effects seen in some cats included mild, temporary diarrhoea and vomiting. Vomiting, neurological signs, intestinal ulceration, increased liver enzymes and kidney damage were seen at higher doses.

Since robenacoxib is 30% excreted by the kidneys, it should be used with caution in cats with CKD, who should be monitored closely. Clinical safety of robenacoxib in feline osteoarthritis: results of a randomized, blinded, placebo-controlled clinical trial (2015) King, JN, King S, Budsberg SC, Lascelles BD, Bienhoff SE, Roycroft LM & Roberts ES Journal of Feline Medicine and Surgery 9 pp1-11 looked at the safety of using robenacoxib longer term in 194 cats with arthritis, including some cats (40) with both arthritis and CKD. The cats who did not receive the placebo were given 1.0-2.4 mg/kg of robenacoxib orally daily for 28 days. The study concludes “Robenacoxib was well tolerated when administered daily for 1 month in cats with osteoarthritis, including cats with evidence of concurrent CKD. There was no clinical indication of damage to the gastrointestinal tract, kidney or liver.”

Robenacoxib Interactions

Do not use robenacoxib at the same time as corticosteroids.

Close monitoring is required if it is used in cats taking ACE inhibitors such as benazepril or diuretics because using these treatments together increases the risk of kidney problems.

Frunevetmab (Anti-Nerve Growth Factor Antibody): Solensia

Nerve growth factor (NGF) is present in the body where there is inflammation or injury, and contributes to pain from such conditions. Previous research has shown that neutralising antibodies against nerve growth factor are effective painkillers for rodents, chronic pain in humans and arthritis in dogs.

A feline-specific anti-nerve growth factor antibody improves mobility in cats with degenerative joint disease-associated pain: A pilot proof of concept study (2016) Gruen ME, Thomson AE, Griffith EH, Paradise H, Gearing DP & Lascelles BD Journal of Veterinary Internal Medicine 30(4) pp1138-1148 examined the efficacy of an anti-NGF antibody called NV-02 (frunevetmab) for arthritic pain and mobility problems in cats. The study concluded “These pilot data demonstrate a 6-week duration positive analgesic effect of this fully felinized anti-NGF antibody in cats suffering from DJD-associated pain.” The treatment appeared to have no side effects, with no apparent effect on kidney function.

In vitro and in vivo characterization of a fully felinized therapeutic anti-nerve growth factor monoclonal antibody for the treatment of pain in cats (2016) Gearing DP, Huebner M, Virtue ER, Knight K, Hansen P, Lascelles BDX, Gearing RP & Drew AC Journal of Veterinary Internal Medicine 30(4) pp1129-1137 induced temporary lameness in cats, which it then treated with anti-nerve growth factor antibody. It found that “Mean lameness scores on all days evaluated following initiation of treatment were significantly lower in the treatment group than in the control group.”

Anti-nerve growth factor monoclonal antibodies for the control of pain in dogs and cats (2019) Enomoto M, Mantyh PW, Murrell J, Innes JF & Lascelles BDX Veterinary Record 184(1) p23 explains more about this treatment and concludes “Overall, the rationale for using anti-NGF therapy in several pain conditions is strong” but states that further research is needed.

Zoetis has a video that explains how NGF affects pain.

Solensia Vet Team explains more about Solensia.

Gabapentin (Neurontin)

Gabapentin is an anti-convulsant, i.e. a medication which is used to prevent seizures. Although nobody actually knows why, it has also been found to help with pain, particularly neuropathic (nerve-related) pain or arthritic pain.

Long-term use of gabapentin for musculoskeletal disease and trauma in three cats (2013) Lorenz ND, Comerford EJ & Iff I Journal of Feline Medicine and Surgery 15(6) pp507-12 looked at the use of gabapentin for arthritic pain in cats. Results “indicated that satisfactory pain management was achieved, administration was easy and no obvious side effects during the period of administration occurred.”

Prescribing practices of veterinarians in the treatment of chronic musculoskeletal pain in cats (2019) Adrian DE, Rishniw M, Scherk M & Lascelles BDX Journal of Feline Medicine and Surgery 21(6) pp495-506 found that gabapentin was the most prescribed medication in the survey, being prescribed by 71% of respondents, even though there is no evidence that gabapentin is helpful for osteoarthritis in cats.

Wedgewood Pharmacy for Veterinary Practices says “It appears to be most effective when combined with other types of analgesic agents, for example NSAIDs, permitting the use of lower doses.”

Mar Vista Vet has an overview of gabapentin.

Pet Place discusses gabapentin.

Gabapentin Formulations

The smallest size of tablet available is 100mg.

There is a liquid formulation available, but this contains xylitol, which is toxic to dogs. There is currently no evidence that it is toxic to cats, and Plumb’s Veterinary Drug Handbook says “In cats, at the dosages used presently, xylitol toxicity does not appear to be a problem with gabapentin oral solution, but use with caution.” Still, some people prefer to avoid products containing xylitol.

Therefore many people have gabapentin compounded for their cats. However, people giving a higher dose (see dosing below) can usually cut the 100mg tablets to an appropriate size.

Gabapentin Dosage

Pet Place says “For pain control in cats, doses range from 1.5 to 5 mg per pound (1.25 to 2.5 mg/kg) every 12 hours. Higher doses (up to 50 mg per cat 1 to 3 times daily) are recommended by some vets.”

Gabapentin is excreted via the kidneys so some vets reduce the dose for CKD patients, who need close monitoring while on the drug. Serum concentrations of gabapentin in cats with chronic kidney disease (2022) Quimby JM, Lorbach SK, Saffire A, Kennedy A, Wittenburg LA, Aarnes TK, Creighton KJ, Jones SE, Paschall RE, King EM, Bruner CE, Wallinger JN & van Haaften KA Journal of Feline Medicine and Surgery 24(12) pp1260-1266 looked at levels of gabapentin in CKD cats compared to healthy cats. The study concludes ” Cats with CKD that received 10 mg/kg of gabapentin had significantly higher dose-normalized serum concentrations than normal cats that received 20 mg/kg, supporting the need to dose-reduce in this patient population.”

Plumb’s Veterinary Drug Handbook (7th Ed.) mentions another benefit of reduced dosing, stating, “Starting the dose at the lower end of the range and increasing with time may alleviate these effects [side effects].”

Gabapentin does not have long lasting effects (it reaches peak levels in the blood in cats about 1.5 hours after dosing, and falls thereafter), so many people find they do need to give it three times a day, which can be tricky if you have to go out to work.

Gabapentin should not be stopped suddenly but gradually tapered down.

Gabapentin Side Effects

Some people believe it may be risky to give anti-seizure medication to a cat who has never had a seizure, though the doses given for pain relief are lower than those given when it is used as a seizure medication. Gabapentin does appear to be safe for cats, with very few side effects.

The primary side effect is sedation. Ataxia (stumbling, wobbliness) may also be seen. Plumb’s Veterinary Drug Handbook (7th Ed.) says “Sedation and ataxia are probably the most likely adverse effects seen in small animals. Starting the dose at the lower end of the range and increasing with time may alleviate these effects. In humans, the most common adverse effects associated with gabapentin therapy are dizziness, somnolence, and peripheral edema.”

Because of its sedative effects, there is actually research into the use of gabapentin as a mild sedative for cats in certain situations. Effects of a single preappointment dose of gabapentin on signs of stress in cats during transportation and veterinary examination (2017) van Haaften KA, Forsythe LRE, Stelow EA & Bain MJ Journal of the American Veterinary Medical Association 251(10) pp1175-1181 looked at its effectiveness for vet visits. The study states “Sedation was a common effect of gabapentin administration, and ataxia, hypersalivation, and vomiting were also reported. All effects resolved within 8 hours after gabapentin administration.”

Plumb’s Veterinary Drug Handbook (7th Ed.) says “Because gabapentin is eliminated via renal routes (practically 100% in humans), it should be used with caution in patients with renal insufficiency.”

Gabapentin Interactions

Mar Vista Vet mentions that oral antacids such as famotidine (Pepcid), ranitidine (Zantac) or cimetidine (Tagamet) will reduce the absorption of gabapentin by up to 20%. Therefore you should give these medications at least two hours apart.

Gabapentin Research

Ohio State University College of Veterinary Medicine has been conducting research into the use of gabapentin in CKD cats to decrease stress during vet visits.

Gabapentin sedation in cats with and without chronic kidney disease (2020) EveryCat (formerly Winn Feline Foundation) gives an update, stating that CKD cats seem to have much higher levels of gabapentin in their bodies at the half life point (the time it takes for 50% of the medication to leave the body after taking it) than healthy cats. This may suggest that vets who reduce the dose in CKD cats could be on the right track.

Painkillers: Not Recommended

The following painkillers are not recommended for cats.

Aspirin

Aspirin is a non-steroidal anti-inflammatory drug. Aspirin can be toxic to cats, who can only metabolise it very slowly, so it is not usually used as a painkiller in cats.

Nevertheless, it is occasionally used to treat heart problems when the benefits outweigh the risks. In such cases it is usually only given in very low doses once every three days.

Aspirin may cause metabolic acidosis.

Mar Vista Vet has information on aspirin.

Carprofen (Rimadyl)

Carprofen is a non-steroidal anti-inflammatory drug used to treat arthritis in dogs. The manufacturer advises against using it in cats, so I would not use it.

Managing acute carprofen toxicosis in dogs and cats (2009) Volmer PA & Mensching D Veterinary Medicine reports on the risks of using carprofen and possible signs of toxicity.

Paracetamol/Acetaminophen

Paracetamol (UK) or acetaminophen or Tylenol (USA) is toxic to cats, with a very narrow safety margin, so even a tiny dose can be extremely dangerous.

Please never give your cat paracetamol/acetaminophen.

International Cat Care explains more about the risks and symptoms.

International Cat Care also has a video about paracetamol and cats.

Tylenol (acetaminophen) toxicosis in cats (1998) Mladenovic D Indiana Animal Disease Diagnostic Laboratory at Purdue University explains more about this problem.

The 10 most common toxicoses in cats (2006) Dunayer EK & Merola V Veterinary Medicine June 2006 pp339-342 lists acetaminophen at number 8.

This page last updated: 04 June 2022

Links on this page last checked: 14 July 2020