Medication - Aspirin


Aspirin tolerance


Q: Dr. Mike: My dog, a 14 year old German Shepherd Mix female is on aspirin twice a day. I see that you highly recommend aspirin for most pain control. But I have never gotten an answer to how much can a large 70-80 lb dog tolerate each day? Can aspirin be toxic in my dog? Is there a maximum dosage? Sometimes my dog shakes when she is lying down or just getting up. Is this shaking from pain especially if the aspirin has "worn off"? She does this shaking not from cold nor wetness. Thanks for your help. I have enjoyed browsing your website to increase my knowledge of my pet's health. Maggie

A: Maggie- Aspirin has the same problems in dogs that it has in people. It can cause gastrointestinal upsets and ulcers if the GI signs are ignored. It can cause renal failure if overdosed. It causes an increase in clotting time. This usually isn't a serious side effect but it does occur. Despite these shortcomings it has a lot of beneficial effects and it is inexpensive. The currently recommended dosage of aspirin varies a little from publication to publication but it is between 5 and 15mg/lb every 12 hours. Since there is a range I usually pick the middle of it and go for about 10mg/lb every 12 hours. This works well and seems to be pretty safe. That works out to an aspirin tablet per 32 pounds of body weight twice a day. I have to admit that I rarely advise giving more than 2 aspirin twice a day despite the fact that some big dogs could obviously take more based on the per pound calculation.

Shaking can be really hard to discern the cause for. I operate under the presumption that most of the time it indicates pain but obviously it could occur when dogs are cold and it can be a sign of nervous system disorders and muscular disorders. I think I have seen references to shaking occurring with some of the hormonal diseases as well.

Mike Richards, DVM

Aspirin Dosage

Q: Thanks for the info . The dog is stiff but does not appear to be in pain, esp when the doorbell rings. What dose of aspirin is best and is enteric coated of any value in dogs? I have him on 325mg/day right now . Steve

A: Steve- I use 10mg/lb. of body weight twice a day for aspirin. Enteric coated aspirin is not recommended in dogs because about half the time the coating isn't digested and the aspirin is excreted whole in the stool.

Mike Richards, DVM

Aspirin for dogs

Q: Dr Mike: My dog is a pure white 6 year old male german shephard. Both his parents were large dogs. He was the runt of the litter, which made him medium in size. In the last year, when it is cold outside, (we live in Colorado) he has problems getting up from a sitting or lying down position. He rises slowly and whines upon movement. No signs of the problem is apparent when weather is warm. He is very active. Runs alot and jumps alot. I cannot afford a visit to the vet, which is very high in our area. My question: How many aspirin can I give him to help with the pain and swelling. Thank you,

A: The dosage of aspirin for dogs is 10 mg/lb, given every 12 hours.  It is extremely important to pay attention to your dog's eating habits when administering aspirin. Dogs have no way to tell you their stomach is upset so you must watch for signs of this. If your dog stops eating while you are giving aspirin it is important to stop giving the aspirin. If any signs of gastric ulcers develop (like blood tinged vomiting or depression) it is important to stop the aspirin.

It is important in German shepherds to distinguish between degenerative joint diseases, such as hip dysplasia, and neurologic diseases, such as degenerative myelopathy. They can have very similar signs but have very different outcomes and somewhat different treatments. When you can afford to take your dog to the vet it would be a good idea.

Mike Richards, DVM

Enteric Coated Aspirin

Q: I saw the Q&A on arthritis and your recommended treatment (aspirin). I have been giving my 45 lb black lab/pointer 250 mg of buffered aspirin w/ his food each day and it seems to help. I've heard that enteric coated aspirin is better than buffered. Do you agree. These tablets are harder to cut; would 325 mg be ok daily?

A: k- There have been one, or possibly two, studies done that indicate that enteric coated aspirin does not work well in dogs. Due to the differences in digestive processes dogs do not seem to be able to routinely digest the coating off the aspirin and many of the aspirin tablets are found whole in the stool. Obviously, if the coating isn't digested the aspirin is not effective.

The dose for aspirin is approximately 10mg/lb of bodyweight every 12 hours. If less works, I'd use less. But if you need to, you can give your dog a whole 5 grain aspirin tablet twice a day with no problem.

Mike Richards, DVM

Last edited 12/14/04


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...