Catster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Can I Give My Cat Aspirin for Arthritis? Vet Reviewed Risks & Advice

Written by: Christian Adams

Last Updated on June 4, 2024 by Catster Editorial Team

sad sick cat

Can I Give My Cat Aspirin for Arthritis? Vet Reviewed Risks & Advice


Dr. Chantal Villeneuve Photo


Dr. Chantal Villeneuve

Veterinarian, MS BVetMed

The information is current and up-to-date in accordance with the latest veterinarian research.

Learn more »

Do not give your cat aspirin for arthritis without very clear and specific directions from your veterinarian. Aspirin can be deadly in cats. And the thing is, there are so many other medications specifically designed for cats that not only are less harmful but work better.

But before we get into that, this article will get into why I don’t recommend giving human drugs from your cabinets to cats, in general.

3 cat face divider

Human Drugs and Cats

The dose of a medication determines not only how effective it will be but how toxic it is. Too much medication—of any medication—can be devastating, even deadly. Conversely, too little of the medication can mean it doesn’t have any of the beneficial effects but can still have negative side effects.

Veterinarians spend a lot of time calculating the exact amount of drug your cat needs to be effective and, importantly, safe. Weight is one of the most important factors in determining how much medication to give. A small cat needs less medication than a big cat.

And cats are much smaller than humans! So, most of the time, human drugs are too potent and too much for our cats. Even if you manage to divide up a tablet into a tenth of its size, the amount of error in that estimation is too great.

It is very hard to guarantee you’re not giving too much human medication to your cat.

assorted medicines close up
Image Credit: JumpStory

The Amount of Medication Is Not Determined by the Size of a Pill

Furthermore, it is confusing because the size of a pill does not correlate with the amount of medication within it.

Medication is made in various concentrations. A can of orange juice concentrate has just as much orange in it as a pitcher but is much smaller. Concentrated small pills can have more medication than dilute large pills, making it very easy to give too much medication by accident.

How the Drug Is Made Determines Its Potency

Human medications, aspirin included, are formulated for human bodies to absorb. Cats are not humans. Their digestive tract is different. So they may not absorb the medication in the same way.

For example, the protective barrier that surrounds aspirin can mean that tablets sit in their stomach undigested, gathering on top of each other, until something triggers them to move on, be digested, and enter the system, all at the same toxic time.

How medication is absorbed by the body impacts how toxic it can be. And since human drugs are not designed for cats, they can cause problems.

Image Credit: JumpStory

Aspirin-Specific Dangers

Cats do not excrete aspirin as fast as humans, meaning it stays in their body longer than someone might expect. In fact, it can take two days for it to leave their system. As a result, it is very easy to overdose a cat on aspirin. If it is given too quickly, it can build up in the body to toxic levels internally.

If your vet prescribes aspirin for your cat, follow the dosing regimen very closely. Do not double up if you miss a dose. And carefully monitor your cat for side effects.

Aspirin is a non-steroidal anti-inflammatory drug (NSAID). They relieve pain by interrupting inflammation as it forms. Unfortunately, a side effect of that interrupting is they also interrupt some other functions of the body.

Importantly NSAIDs can interrupt the GI tract and the kidneys from working normally if they are too strong. So, if too much aspirin is in your cat’s system at the same time, it can injure the kidneys and the GI tract.

The safety margin of aspirin in cats is small and, therefore, dangerous.

cat paw divider

Frequently Asked Questions (FAQs)

What is aspirin toxicity?

If your cat accidentally eats aspirin, they can have what is called aspirin toxicity. Several body systems can be affected, mainly the gastrointestinal tract, the liver, and/or the kidneys.

Bring them to a vet right away if you know your cat has ingested aspirin—and the earlier, the better!

a cat that feels sick and seems to vomit
Image Credit: chie hidaka, Shutterstock

How do I know if my cat has aspirin toxicity?

Below are some of the signs to watch out for in case of aspirin toxicity:

  • Lethargy and depression
  • Breathing too fast
  • Seizures
  • Coma
  • Stomach ulcers
  • Liver disease
  • Gastrointestinal problems—vomiting, diarrhea
  • Kidney disease

Can my cat have aspirin with its other meds?

Other medications can compound the side effects of aspirin.

Arthritis is usually an old cat disease. And unfortunately, old cats often have more than one health problem. This can make giving aspirin even more dangerous, as complications from either the disease or other medications used to treat the disease can easily occur with aspirin.

Other medications that are in the same category of pain relief, NSAIDs, all have similar side effects. And if two different types are given, then the side effects are made that much worse. Many cats are on steroids. Steroids reduce inflammation, and are similar but not exactly like aspirin and NSAIDs. As a result, if aspirin and steroids are given together, they can have severe side effects.

Sick cat, IV, dehydration, dropper
mage Credit: Vladimir Gudvin, Shutterstock

Can my cat have aspirin with heart disease?

Many of the common heart medications used in cats can cause toxicities when used with aspirin or become less effective at helping the heart, which is also a very dangerous situation. Some examples of those heart medications are:

  • Furosemide
  • Spironolactone
  • ACE inhibitors

Can my cat have aspirin with kidney disease?

Kidney disease is common in cats. And so, drugs that impact the kidneys need to be used with extra caution, like aspirin. Since one of aspirin’s main side effects is to the kidneys, it can be especially dangerous to cats with kidney disease.

cat paw divider

Final Thoughts

Do not give your cat aspirin out of your cabinet. It just is not worth the risk. There is a potentially deadly risk, especially if you give it once a day because they take two days to process it. If you are worried about their painful arthritis, bring them to the vet for better drugs to manage the condition.

Featured Image Credit: Julia Cherk, Shutterstock

Get Catster in your inbox!

Stay informed! Get tips and exclusive deals.
Catster Editors Choice Badge
Shopping Cart


© Pangolia Pte. Ltd. All rights reserved.