Medicines
Is naproxen toxic to cats and dogs?
Also sold as Aleve, Naprosyn
Cats
Highly toxicDogs
Highly toxicNaproxen is far more dangerous to pets than to people. Dogs clear it very slowly, so a single tablet can cause stomach ulcers and kidney damage in a medium-sized dog. Cats are even more sensitive.
By Maya HartIf your pet got into it
- Call your vet or a pet poison helpline now, even if your pet seems fine.
- Have the packet ready: the vet needs the name, strength and how much may be missing.
- Do not make your pet sick unless a vet tells you to.
- Because naproxen stays in the body for days, treatment usually lasts several days too.
Signs to watch for
- Vomiting, sometimes with blood
- Black, tarry stools
- Loss of appetite
- Drinking and urinating changes (kidney damage)
- Wobbliness or seizures at high doses
How much is dangerous
In dogs, stomach ulcers have been reported after doses as low as about 5 mg per kg — part of one 220 mg tablet for a small dog. There is no safe dose for cats.
Keeping it safe
- Keep all painkillers in closed cupboards
- Never give human painkillers to pets
The details
In people, naproxen lasts long enough to be taken twice a day. In dogs its half-life is around 74 hours, so a single dose keeps working for days. That is why a tablet that seems small can do serious harm, and why vets often keep poisoned dogs on a drip and stomach protectants for several days.
Questions owners ask
Is naproxen toxic to cats?
Yes — highly toxic.
Is naproxen toxic to dogs?
Yes — highly toxic.
How much is dangerous?
In dogs, stomach ulcers have been reported after doses as low as about 5 mg per kg — part of one 220 mg tablet for a small dog. There is no safe dose for cats.
What should I do if my pet got into it?
Call your vet or a pet poison helpline now, even if your pet seems fine. Have the packet ready: the vet needs the name, strength and how much may be missing. Do not make your pet sick unless a vet tells you to. Because naproxen stays in the body for days, treatment usually lasts several days too.
Sources
Tailwise is for general information and is reviewed by veterinary professionals, but it is not a substitute for advice from your own vet, who knows your pet. How we check facts