Never give aspirin to a cat.
Aspirin is highly toxic to felines, and even a small dose can trigger life-threatening complications.
Signs of aspirin poisoning may include vomiting, diarrhea, loss of appetite, lethargy, weakness, tremors, seizures, kidney failure, and liver damage.
If you suspect your cat has ingested aspirin, contact your veterinarian or an emergency animal clinic immediately.
Cats process many human medications differently than we do. A drug that seems harmless to people can be deadly for a cat. Always consult a licensed veterinarian before giving your cat any medication, including over-the-counter products.