Aspirin not the best anti-inflammatory medicine for pets
A few times a year, we'll have a pet owner come in to our office and state they're giving their pet (usually a dog) "doggie aspirin." Most veterinarians recommend not giving aspirin to pets because of the potential for serious or life-threatening complications.
A little background on non-steroidal anti-inflammatory (NSAID) drugs would be helpful at this point. This large class of drugs includes aspirin, ibuprofen, naproxen and many others in the human realm, and drugs like carprofen (Rimadyl and generics) and meloxicam (Metacam and generics) and others in the veterinary realm. Acetaminophen (Tylenol) is not, technically, an NSAID; it relieves pain and fever, but does not reduce inflammation. All NSAIDs have the potential to cause side effects, including stomach irritation or ulcers or problems with the liver or kidneys, and to inhibit blood clotting.
Aspirin is a special case because it was already in wide use when modern drug laws and approval processes were developed, so it was "grandfathered" and did not have to prove its safety and effectiveness like newer drugs have to. I've heard it said that aspirin would probably not be approved for human use under current regulations, or would be a prescription drug, because of the frequency of side effects. I can't take aspirin because it causes too much stomach irritation for me. The grandfather status allows aspirin to be sold over the counter without a prescription, but it's not the best choice for pets.
Our pets are not just small humans, and their metabolisms and the way they handle some drugs can be significantly different from people. In the case of NSAIDs, there's enough difference in the way certain molecules are handled that we know that the humans drugs are more likely to cause serious issues if given to pets, and we have much safer molecules to use for our pets.
Aspirin has shown the ability to cause stomach ulcers in dogs after as little as one dose. It's also one of the most potent inhibitors of blood clotting, and I have seen at least one dog die from a bleeding stomach ulcer during my career. Ibuprofen can cause significant liver damage in dogs. A number of dogs were sickened when it was approved for over-the-counter sale for humans a few years back and their owners decided to give it a try without consulting their veterinarians first.
Veterinary-approved NSAIDs are safer for pets and much less likely to cause problems in pets than human-label drugs. Notice I said "less likely." There's still the potential to have issues in a small percentage of pets even with the approved products, and that's why they are prescription products to be used under the supervision of a veterinarian only.
Of course, cats are not just small dogs, and they're different relating to NSAIDs, too. They don't metabolize these drugs as well as dogs and people do, and the ones that are labeled in the U.S. for use in cats are labeled for only one dose, or to be given for only three or four days. In other parts of the world, however, some of these drugs have labels indicating they can be used for longer periods, but a doctor's supervision is needed, as always.
Veterinary-approved NSAIDs are much safer than aspirin for pets, so consult your pet's doctor before reaching for the aspirin bottle.
Dr. Greg McGrath, a veterinarian at Cedar Lake Pet Hospital in Biloxi, encourages questions for this column. Write to South Mississippi Veterinary Medical Association, 20005 Pineville Road, Long Beach MS 39560 and include a self-addressed stamped envelope.
This story was originally published March 10, 2016 at 4:05 PM with the headline "Aspirin not the best anti-inflammatory medicine for pets ."