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.
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.