Pain in Cats


Aspirin or Acetaminophen

DO NOT give any cat a non-steroidal anti-inflammatory medication without consulting with your vet first. Acetaminophen is toxic to cats, aspirin is extraordinarily easy to overdose in cats because the half-life of aspirin in a cat is 72 hours (3 days!) and other non-steroidal medications do not appear to have been studied much in cats, probably due to the problems with these two common ones. For arthritis, we do sometimes use aspirin but it must be used cautiously and it is important to know the patient's medical condition well prior to its use.

Treating pain in cats - Adequan (Rx), glucosamine/chondroitin and prednisone

Q: Dear Dr. Richards, Thirty days ago, I began a schedule of Prednisone (5mg) and Glucosamine/Chondroitin Sulfate (250mg/200mg) for my arthritic cat. I don't like having her on Prednisone, so try to administer it only once every 3 days. I break a G/C capsule open and mix the powder into her cat food. She doesn't like it much, but most of the time I can get her to eat it. You also mentioned Adequan injections as being possibly helpful. My vet has never done this, but she ordered the Adequan and it's arrived, so we're ready to begin.

These are my questions: * to begin the Adequan injections, do I continue with the Prednisone and G/C dosages at the same time? * how much Adequan do we administer and how often? Is it just used initially, or ongoing? * are you aware of any other form of G/C to administer to my cat? I would even prefer a pill that she can swallow, but those capsules are much too large. * what side-effects should I be watching for for the Prednisone? And would you recommend that I ease her off of it to see if the G/C and Adequan are working by themselves?

As you know, it's difficult to monitor pain in a cat. Her arthritis is in her shoulder and elbow and she walks with a limp. My vet said her shoulder joint is a little out-of-whack so there will always be a limp. So the limping doesn't monitor the pain. However, every few days she will lift her paw off the ground and hold it up. I think that might be the pain signal, so that's what I'm watching for.

Thanks for your help. Nancy

A: Nancy-

There is no reason not to use Adequan (Rx), glucosamine/chondroitin and prednisone at the same time, if the combination seems to help more than the individual medications. In most cases, though, the object is to use as little prednisone as possible and so we try to wean cats off of it during treatment with Adequan, in the hopes that will be OK.

Adequan is dosed at the rate of 5mg/kg (approximately). There are all sorts of recommended dosing schemes. We usually give it weekly for 5 weeks and then try to lengthen out the interval to the longest time between injections that keeps the cat or dog comfortable. Two to four weeks seems to be about the range that can be expected for Adequan to help. Different vets have tried lots of different schedules. Adequan is pretty safe to use, so it is OK to experiment some with the intervals.

Glucosamine comes in a powdered formula. One brand name for this is Arthroflex (TM). One of my clients loads the powder into gelatin capsules and gives it that way. Some cats will eat the powder mixed with their food but cats that are sensitive to texture or the taste may not accept food with glucosamine products mixed into it. There are a lot of companies making these products right now and it would not surprise me if there are companies making other formulations that might be easier to give (like capsules or smaller tablets). I haven't really looked into this recently but if I get a chance in the next few days I will.

Prednisone doesn't cause too many obvious side effects in cats but weight gain from increased appetite and some fluid retention is pretty likely. It is necessary to try to control the weight gain by feeding less because increased weight is bad for arthritic pets. The side effect that scares me is immunosuppression. If you find that you are seeing more upper respiratory infections, more skin disease, or anything else that indicates a decrease in immune function it would be a good idea to discuss this with your vet. At every three day intervals it is not too likely that this will be a problem for your cat but it is a good idea to stay vigilant for signs of problems.

Good luck with this. I expect to see more emphasis on finding medications that are useful for pain and inflammation in cats over the next few years, so ask your vet every now and then if anything new is available. Cats have been frustrating due to their inability to process many anti-inflammatory medications or odd reactions to others so there is some chance that things won't change much. Still, there is a good economic incentive for coming up with a good anti-inflammatory for cats so there is hope.

Mike Richards, DVM 5/5/99

Rimadyl and pain control for Cats

Q: Dear Dr. Mike: I've been surfing the web for the past week looking for anything regarding cats and Rimadyl and found your website, including the Q & As. We took our 10 year old persian to the vet last week and he was diagnosed with arthiritis and given an RX of D-Glucosamine Sulfate, further medication would wait until his blood work came back. His bloodwork came back negative and the vet has recommended a muscle builder and also mentioned Rimadyl to us, including that he was going to see if he could find a cat dosage for us, as it has been used in the UK for the last four years for both cats and dogs (and cows, etc. - as I have come to learn thru my web-surfing and reading UK vet journals - ah, the places we can go...) Anyway, after reading several different US based articles on Rimadyl (known as Zenecarp in the UK) I am concerned about even considering giving Rimadyl or Zenecarp to my cat. Can you enlighten me any further than what is in your Question and Answer sections? I appreciate any advice or suggestions you have, I love my cat and hate to see him in pain - sincerely, Karen

A: Karen- The situation with Rimadyl (Rx) and cats is a little confusing. Apparently there is an injectable form of carprofen (generic name of Rimadyl) available in some countries. This formulation has been used in cats with reasonable safety. The oral form of the medication available in the United States may or may not be as safe. Rimadyl is not approved for use in cats and there would be no recourse with the company if it should be used and problems occurred.

Pain relief is very problematic in cats and we do not have a really good solution for long term control of the pain associated with arthritis in cats. I think it is justified to use cortisones for long term management of arthritis in cats when there is recognizable pain even though it is likely that they may slight hasten the arthritic process. I just think that a slightly shorter, much more comfortable life is better than a longer more painful one. Of course, that is obviously an arguable point.

We have used Adequan (Rx) in cats for arthritis and have felt like there was some benefit in several patients. It doesn't work quite as well as cortisones but may be a reasonable "middle of the road" approach.

Good luck with this! Perhaps the oral glycosamines will work well enough to make it possible to put off all these choices for a while.

Mike Richards, DVM

Assessing pain in cats:

Q: This may seem like a strange question, How can you tell if a cat is in pain. I have a 17yo mixed male cat that he recently had a seizure after jumping off the bed. So I took him to the vet. The vet said he may be experiencing kidney or liver failure. When I brought him into the vet she said that it was probably time to put the cat to sleep, I asked if there was anything that could do, so they gave it a saline treatment and he seems to be doing pretty good, eating, drinking, going to the litter box the usual cat stuff. How do you tell if your cat is in pain if he is having health problems and is not seeming to be doing anything out of the norm, like meowing or making strange movements. Any help would be greatly appreciated.

A: It can be very difficult to tell if a cat is in pain. Some cats will hide even really severe pain. We see a number of cats with injuries that have to be excruciatingly painful, such as fractured pelvises or major fractures who show almost no outward signs of pain. We have come to believe in our practice that cats should be treated for pain whenever it seems logical that they might be in pain, whether they show it or not. Some signs of pain are depression, lethargy, seeking solitude, reacting to being touched or approached, not eating, having visible third eyelids (the white film that partially covers the eye from the middle corner at times) and more obvious signs like crying out or aggressive behavior when the painful area is touched. Not all cats with one or two of these signs are experiencing pain and not all cats show any of these signs when in pain. There are definitely times when it would be really nice to be able to ask our patients questions and assessing pain is one of those times. Renal failure often responds to fluids. We have a link to a very good renal failure in cats site on our link page. It would be worth checking it out.

Mike Richards, DVM

Medications for arthritis in cats:

Q: Our 17 year old cat, Mouser is extremely stiff in the hind quarters and cries sometimes when you pick him up as if he's in pain...our vet has run the usual tests on him and confirms that he has arthritis but is otherwise healthy. His kidney function is relatively good considering his age. Mouser used to be a huge cat but has lost a great deal of weight over the past 4 yrs. and hardly has any muscle on his old bones anymore. To pet him, you'd think we were starving him to death but his appetite is very good. A couple of weekends ago, we sensed Mouser was in some pain with his arthritis and the vet filling in on Saturday gave us a steroid shot to take home to give Mouser. She said it would probably perk him up and make him more comfortable but that there were other drugs out now that we could talk about with his regular vet that didn't have the side effects that the steroids did. Mouser did perk up for about a month and then seemed to regress again. Last week I talked to his regular vet and he advised us to start him on Adequan injections once a week for 3 weeks and then he would probably only have to have an injection once every month or two. He said this had been very successful in race horses and seemed to help cats as well. We gave Mouser his first injection which was only 0.15 and we haven't really seen any improvement in him this week. This was such a miniscule amount that we wonder if it did him any good. Does this drug have to build up over the next few weeks to do him any good? Is there anything you can tell us about this particular drug and what it will do to help our old this point we just want to keep him comfortable but don't want to jeopardize his other health. Our vet seemed to think that giving him the steroids would help him to feel better but it had so many side effects such as kidney problems which old cats don't need any more of than they already have. We would appreciate it if you could give us any info you might have on this particular drug used in cats. Thanks

A: Adeqan has not been approved for us in dogs or cats, so there is not a lot of information from field trials or anything like that. I have seen recommendations for its use in cats, though. Adequan is made for horses and that is probably one of the reasons it doesn't take very much to meet a cat's needs. Adequan is a natural anti-inflammatory medication that does seem to be beneficial for control of arthritis, based mostly on anecdotal reports. The usual recommendation is to give it once a week for several treatments (between 3 and 6) and then to give it every 2 or 3 weeks as necessary. Based on our experience it appears to be beneficial about 60 or 70% of the time.

There aren't very many choices of medication for cats with arthritis since they are sensitive to most non-steroidal anti-inflammatory medications, like acetaminophen and aspirin. Adequan is one of the few non-steroidal medications that may be helpful. It sounds like it would be a good idea to consider checking Mouser for hyperthyroidism (causes weight loss while the appetite remains good) and low potassium levels, which can cause muscular weakness and pain.

Mike Richards, DVM

Last edited 09/17/02


Michael Richards, D.V.M. co-owns a small animal general veterinary practice in rural tidewater Virginia. Dr. Richards graduated from Iowa State University's College of Veterinary Medicine in 1979, and has been in private practice ever since. Dr. Richards has been the director of the PetCare Forum...