Why is aspirin dangerous for pets?
Aspirin is a non-steroidal anti-inflammatory drug (NSAID). Pets break it down slowly, so a single "human dose" can ulcerate the stomach lining and harm the kidneys. Cats are especially vulnerable because they lack the enzyme that clears it quickly.
About the dose levels
Reference bands for dogs: <25 mg/kg low risk · 25–50 mg/kg watch and call · 50–150 mg/kg see a vet now · >150 mg/kg emergency. Treat cats as roughly twice as sensitive. These values are estimates — always call your vet if your pet is showing any symptoms.
Reference bands for dogs: <25 mg/kg low risk · 25–50 mg/kg watch and call · 50–150 mg/kg see a vet now · >150 mg/kg emergency. Treat cats as roughly twice as sensitive. These values are estimates — always call your vet if your pet is showing any symptoms.
Signs to watch for
- Vomiting (sometimes with blood), dark or tarry stools
- Loss of appetite, drooling, abdominal pain
- Lethargy, weakness, pale gums
- Rapid breathing or panting
- Kidney failure signs: increased thirst and urination, then reduced urine
What to do right now
- Call your vet immediately if more than one low dose has been swallowed or any symptom is present.
- Do not give a second dose — and never give human painkillers without your vet’s say-so.
- Bring the pill bottle so the vet knows the exact strength and number of pills.
- Induce vomiting only if your vet or poison control tells you to — never if the pet is drowsy or already vomiting.
If your pet shows any of the signs above, go to the nearest emergency vet now and call ahead.
For a dose worked out against your pet's weight, use the Aspirin Toxicity Calculator.