Medication - Non-steroidal anti-inflammatory drugs (NSAID)


Acetaminophen (Tylenol™) safety in dogs and cats

Question: Hi Dr Mike:

I have a question about Acetaminophen (Tylenol™). The Receptionist at our local veterinarian told us that in case of fever, it was ok to give our dogs a Tylenol™ and NOT to give them ASPIRIN, or IBUPROFEN.

According to the AVMA Pet Poison Guide ratings scale, it appears to me that the Acetaminophen (Tylenol™) is more dangerous then the ASPIRIN, or IBUPROFEN. Is this true or am I misunderstanding what I am reading or was this by chance a misprint?

What would you recommend be given to a dog in case of a fever ASPIRIN, IBUPROFEN, Acetaminophen (Tylenol™) or something else?

Thank you for your time. I hope to hear from you soon, David

Answer: David-

Based on reactions in our canine patients, this is the ranking I would give these medications: safest = acetaminophen (Tylenol tm), also safe = aspirin, less safe = ibuprofen (Advil tm, Motrin Rx). However, this is the ranking that I would give them based on the reports in the literature and factoring in the likelihood of a bad reaction causing death: safest = aspirin, also safe but less so = acetaminophen and less safe = ibuprofen.

The reason for these rankings include these things. Aspirin is reasonably likely to cause gastric ulcers, which can be life threatening if ignored but which respond to withdrawal of the medication. Acetaminophen doesn't seem to cause ulcers but there are uncommon reactions to it in which liver failure occurs and this may not respond to therapy, so death is a possibility. Ibuprofen is very likely to cause ulcers, with 100% of dogs developing ulcers with the use of ibuprofen in at least one study. On the other hand, lots of my clients come in and tell me "I gave my dog an ibuprofen last night" and I have only had to treat one or two cases of ulcers and I can't recall a dog dying from this medication, yet.

My personal preference for pain and fever in dogs is aspirin but we do warn our clients to discontinue the medication if the dog stops eating and to call us or come in for a recheck if that happens.

In cats the situation is different. Acetaminophen is very toxic to cats and this medication should simply never be used to treat a cat. Aspirin has a long half life in cats, at least 24 to 48 hours, so it will reach toxic levels pretty quickly if it is given more frequently than once every 48 hours and the dosage is 10mg/lb so a baby aspirin (81mg) is a much more appropriate dosage for a cat than an adult aspirin. I have not seen much information on ibuprofen and cats but it is a good idea to avoid all non-steroidal anti-inflammatory medications in cats, at least until one of them does prove to be safe in someone's clinical trials.

Mike Richards, DVM 3/10/2001


This is sort of a p.s. to the previous note. My guess is that the AVMA figures that it is safer not to confuse people with the difference between the effects of acetaminophen in dogs and in cats. I have several pain control references which state that acetaminophen is generally safe in dogs and it is used frequently because hydrocodone/codeine + acetaminophen combinations are pretty effective for post-surgical pain and for chronic pain from arthritis in dogs. The general feeling is the the narcotic provides the pain relief in this combination, though.

Mike Richards, DVM 3/10/2001


Question: Hi Dr. Michael:

Can you tell me if EtoGesic is holding up to the promotional material that suggests it is better than Rimadyl with just one pill a day?

I read something (that I cannot put on hands on now) that said there were serious side effects and to use it with great care. True?

If it is as good as the company claims then how does it compare price wise with Rimadyl?

Thanks, C.

Answer: C.-

It is easiest to answer your questions in reverse order.

Unless the pricing has changed on either Rimadyl (Rx) or Etogesic (Rx) the per day pricing is just about exactly the same overall but there are minor variances depending on the weight of the pet (if a pet hits the dosage just right for one or the other of the pills there can be slight price advantages). I don't think it is a huge coincidence that these medications are so close in price. Pharmaceutical companies all work on "what the market will bear" pricing scheme so they charge what people will pay for pain relief for their pets.

Both Rimadyl (Rx) and Etogesic (Rx) can cause serious side effects. Patients on both of these medications should be watched carefully for signs of inappetance, lethargy or really any sign of not doing well. It is recommended that serum blood chemistry testing be done prior to using the medications and one week to a month or so after starting them. We don't always do this, due to the cost, but we advise all clients to call us if there is any change in a pet's behavior and especially eating patterns, while on these medications. Liver or kidney damage and gastrointestinal problems such as ulcers can occur with these medications. On the other hand, they provide a great increase in comfort for a lot of patients. I have a very personal perspective on chronic pain and I can tell you that I choose to take the small overall risks associated with non-steroidal pain relievers on an almost daily basis --- so I don't see a problem with making that choice for my own pets. It is just a good idea to be cautious.

We use primarily Rimadyl (Rx), only because we started using it first and because lots of times it works pretty well given once a day, too --- in which case it is less costly. Since I have limited personal experience with Etogesic (Rx) the best I can say is that pretty much all the veterinarians I have spoken to who use both medications say that one works better in some dogs and the other works better in other dogs. Just like in people with the various non-steroidal products like ibuprofen, aspirin and acetaminophen, one sometimes works better for a particular individual than the other one.

I still like aspirin best. I use it first and I use it until it doesn't seem to be working anymore, or until it cause gastrointestinal upset. I have a lot of patients on glucosamine/chondroitin products, too. I still have some questions about the efficacy of these products but many people are sure their dogs do better on them and they seem to be very safe so we do recommend giving them a try.

Hope this helps some.

Mike Richards, DVM 11/3/99


Q: I just discovered your website and have marked it as a "Bookmark" for future reference. I read with interest the questions and answers from dog owners on the side effects of Ketoprofen. I also have a question and would very much appreciate a response. I have a 3 1/2 year old German Shepherd/Samoyed mix (she's beautiful!) who was diagnosed several weeks ago with hip dysplasia, both hips. Needless to say I am devastated. I did everything right from the time I brought her home as a puppy. I took her off puppy food at 3 months and on to the best adult kibble available (Gastro Intestinal Kibble from the vet)- I don't feed her people food, and give her fruit, raisins, vegetables etc for treats rather than junk food from the pet store and yet she has this debilitating condition. She is on Glucosamine, one pill a day forever and initially was on 1/2 Ketoprofen for 10 days. The Ketoprofen worked immediately, however, once she was off it within a few days she was yelping everytime she tried to lie down or go up the stairs. My vet agreed to give me a second prescription of the Ketoprofen with the understanding it would be given only on the days she was in extreme pain. This is a dog who is used to an hour every morning of running with me before work, and an hour of hiking through the woods in the early evening - rain, shine, snow etc. Because of where I live I am fortunate that I can provide Scout with two hours of off leash running every day. Now I'm afraid to let her off leash as it seems the day after she's had a good run through the woods the pain returns. The pain seems intense, and she paces up and down afraid to lie down and her tail is tucked up between her legs with ears flat. How long can I continue to give her the Ketoprofen before I start to see signs of liver disease, and what are the signs of liver disease? On her bad days an hour after giving her the Ketoprofen she is back to normal! Thanks so much for your help.

A: Dear Peggy,

I have not used very much ketoprofen because there have been reports of problems with gastric ulcers occurring with ketoprofen more frequently than with carprofen (Rimadyl Rx) and I became aware of both medications at about the same time.

Either medication could produce liver problems but it is not a highly likely outcome with either medication. At present I think that the reactions involving liver damage are unpredictable and occur in a few individuals for unknown reasons. I am not uncomfortable using Rimadyl on a chronic basis when it seems to be necessary. It is a good idea to monitor a dog on carprofen for signs of liver damage. Inappetance, lethargy, vomiting and jaundice may occur with liver disease. It is important to stop administering Rimadyl and to call your vet if your dog stops eating while on this medication. It may be worthwhile to ask your vet to draw blood to check for elevation in liver enzymes after starting Rimadyl. I still like aspirin as an alternative, too. It is more likely to cause ulcers but most dogs can tolerate it even when used on a continuous basis for long periods. Like the other non-steroidal anti-inflammatories it is important to stop using it if your dogs stops eating. The glucosamine and chondroitin products do seem to help and are also worth keeping up with as long as you are seeing a benefit.

You should consider whether surgery to provide longer term comfort is an option for you and Scout. Total hip replacement surgery is a good option if you can afford the cost of the surgery. Most dogs do very well after surgery. It is possible to nearly eliminate pain rather to moderate it. Scout has a lot of years left to live with his hips and he might really benefit from total hip replacement.

I hope that you are able to help Scout be more comfortable.

Mike Richards, DVM

Pain control in older dog

Q: Dr. Mike,

Thanks for the quick response. We Started Muffy on Anipryl on Thursday.

Another problem has surfaced. Last Friday Muf fell down the stairs and bruised her already weak back legs. She currently takes 100 mg of Rimadly daily.

She seems very very sore. Would it be OK to supplement her with some aspirin too until she gets over this?? Muf is about 55 lbs (Springier Spaniel)

Also, if the Anipryl doesn't work would it be OK to try Prozac??

Thanks Dr.Mike, you are a life saver. As you can see we love Muffy more than anything and want to make her as comfortable as possible.

Rick & Darleen (Muffy's Mom & Dad)

A: Rick-

I would be very hesitant to use aspirin and Rimadyl at the same time. Both of these medications are non-steroidal anti-inflammatory drugs (NSAID) and as such, they have the potential to irritate the gastric and intestinal linings. While Rimadyl is formulated to minimize this risk it still has some potential to cause irritation and the effect might be cumulative with aspirin.

I think that there will be more and more information available on helping older dogs through age related problems with medications but currently there isn't a lot of concrete information on drugs like fluoxetine (Prozac Rx) and their effect on these problems. There are fairly well established dosages for this medication, though, so trying it seems reasonably safe if Anipryl (Rx) is not beneficial.

If Muffy will allow you to use hot or cold compresses on the sore areas you might that they are beneficial. Just a heating pad set on low that Muffy can choose to lay on if she wants to might be beneficial. Sometimes gently massaging sore areas seems to help, too. Pets are like people -- sometimes the little things help as much as medications. There are several commercially available heated pet beds or heating elements designed to be safe to use for pets.

It is possible to combine narcotic pain relievers, such as butorphenol (Torbugesic SA, Rx) or hydrocodone (Hycodan Rx) with an NSAID, to get more pain relief. We have found this combination to be helpful in many instances for pain that either medication alone just can't quite control.

Hopefully Muffy is already feeling a little better.

Mike Richards, DVM

Piroxicam (Feldene Rx)

Piroxicam (Feldene Rx) is a non-steroidal anti-inflammatory medication that has a direct toxic effect on some cancers, including transitional cell carcinomas. I think the exact mechanism of this action is unknown. Other than the usual NSAID side effects (occasional kidney damage, gastro-intestinal irritation) it seems to be a pretty safe medication. Many vets use medications to protect the stomach while administering this medication but some do not.

To the best of my knowledge there is not an alternative chemotherapeutic regimen with a better record against this condition. Mike Richards, DVM

Carprofen and other NSAIDS

Q: My question deals with Carprofen. Is there any information which compares equivalency to other NSAIDS. Are there other NSAIDS in the class such as ibu and keto profen which are also effective and save in dogs? Can you recommend some literature on this subject? Thank you for your help

A: I have not seen an equivalency chart for NSAIDS similar to the ones published for corticosteroids and opiates. If I run across one, I'll try to remember to put the information it contains online. Carprofen (Rimadyl Rx) is supposed to be a more potent pain-reliever and a slightly less potent anti-inflammatory than the other NSAIDS which are approved for dogs.

Ibuprofen and ketoprofen have both been implicated in gastric ulcer formation in dogs. These medications are supposed to be able to cause ulcers in most dogs with just a few days dosage (5 days to a week). There are occasional reports of ulceration with just one or two doses. Therefore, they are not commonly used in veterinary medicine. Indomethacin (Indocin Rx) also has a strong tendency to cause ulcers in dogs.

I have a few clients who report that they have used ibuprofen without problems but I have also treated two dogs for severe ulcers associated with this medication so my clinical experience comes close to matching the literature reports. Mike Richards, DVM

NSAIDS and Nutriceuticals

Q: Thanks for the Information on Rimadyl. Can any other NSAID be used in dogs? This stuff is outrageous in price. Have you any experience with Cytotec in conjunction with these drugs in dogs? Steve

A: Steve- I still like aspirin a lot. Prior to the approval of carprofen (Rimadyl Rx) we used aspirin in conjuncion with hydrocodone with good success in several patients in which aspirin was not sufficient for relief of pain. Some vets use phenylbutazone and believe that it works better in many patients. This hasn't been my experience but I can't argue with their perception. Other alternatives include Arquel (Rx), whose generic name escapes me at the moment and the whole range of glycosaminoglycosans, including Adequan (Rx), Glycoflex (tm), Cosequin (tm) and others. These "nutriceuticals" are considered to be helpful by many people. Little things like providing a warm or soft bed, spending a few minutes massaging sore legs or ensuring regular moderate exercise can all help. If your dog is overweight the single best thing you can do is to help him or her lose weight. This does more to relieve the pain associated with arthritis than medications in many instances. Rimadyl (Rx) is fairly expensive, especially for a medication meant to be used on a continuous basis but it works well and people continue to buy it so I think the price is likely to stay about where it is for awhile.

Mike Richards, DVM

Is one NSAID the same as another?

Q: Dear Dr. I have a 13 y. o. female St. Bernard. She weight approx. 125-130# and a few years ago was given pred. (20mg) one tablet q other day for hair loss. We tried diet, shampoo, and finally thyroid (misdiagnosed) before getting good results with the prednisone. Due to her weight and age, she's developed arthritis (osteo I'm assuming) and was limping and not putting weight on her rear right leg. I tried her on Glucosamine with the pred. (from health food store since the vet wanted over $80 for their dose) with no effect. Recently she started taking Rimadyl with fantastic results. Needless to say, we're cutting down and d/c the Pred. The only problem with Rimadyl is the cost. The dose she's taking of the Rimadyl in 100mg BID. I am assuming that the chemical structure and pharmaceutic properties are similar to ibuprofen. I'm sure that ibuprofen would be safe for the dog especially because of her weight. I only worry about gastric bleeding. Is Rimadyl safer in that respect, or should I ask her vet about trying ibuprofen. On the same note would ketoprofen be safe (I'm assuming its much more potent- 10X and may no be as safe for her tummy). Just out of curiosity how do vet's feel about acetominophen, ASA, Naproxen for pain management. Thank you

A: Please do not substitute ibuprofen for carprofen (Rimadyl Rx)! Although both of these medications are non-steroidal anti-inflammatory (NSAID) medications, they are NOT the same. Ibuprofen causes ulcers in most dogs in which it is used chronically. Most NSAID medications are much more likely to cause ulcers in dogs then they are in people.

Aspirin seems safe to use in most dogs but does cause ulcers or gastrointestinal upset in some dogs.

Acetaminophen is probably safe for most dogs but it causes liver damage in a small percentage of them. It should NEVER be used in cats as it almost always causes severe liver damage in this species. Due to the slight increase in potential for side effects in dogs and the severe consequences of people thinking that it might be OK to use in cats, almost all vets are reluctant to recommend this medication.

Ketoprofen has been advocated by some vets for short-term use in situations such as post-surgical pain but advise against long term use and other vets report high incidences of ulcers associated with its use for more than 3 to 5 days, so it may not have much benefit in your situation. Naproxen seems to have some advocates and other doubters, as well.

Your vet probably has an oral glycosamine product that is less expensive than the $80/dose version, which I suspect was Adequan (Rx), an injectable version of these medications approved for use in horses only but commonly used in dogs. There still is not a lot of objective information on these products, unfortunately.

Rimadyl will probably not be released for humans because it doesn't appear to be much more effective in us than ketoprofen, which has the advantage of once a day dosing. In dogs it is much less likely to cause ulceration than other NSAIDS currently available so it has a niche. Unfortunately, it is expensive and will be until the patent rights run out.

Mike Richards, DVM

Aspirin, Advil or Tylenol? I take it..can my dog?

Q: My two male dogs got into a fight but are ok. Accept for some swelling. Once before when this happened the vet told me to use either aspirin, advil or tylenol...I cannot remember which...could you please tell me which medication is ok with canines? And how much you would give per pound? Thanks ..

A: Advil and all ibuprofen products are very likely to cause ulcers in dogs. This can happen in as few as 1 or 2 doses with these medications. Tylenol and other acetominophen products are sometimes implicated in liver damage in dogs, although this appears to be a rare problem. Aspirin is usually safe to use but does cause stomach upset in some dogs and can cause ulcers. It would be best to call your vet and get a dose for your dog and possibly to consider having the swelling checked out as well. Aspirin is not recommended in injuries in which the swelling may be due to hemorrhage as it can promote bleeding. Despite their "over the counter" nature in humans, it really is best to consult with your own vet, who knows your dogs, prior to using these medications.

Mike Richards, DVM


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...