Action should be taken immediately if a cat eats chocolate, as chocolate contains theobromine, which is toxic to cats. Mild poisoning symptoms may include vomiting, diarrhea, hyperactivity, and rapid heart rate. If you suspect your cat has ingested chocolate, first assess the amount ingested and the type of chocolate (dark or baked chocolate contains higher levels of theobromine).

Next, closely observe the cat's behavior and physiological responses. Most importantly, contact a veterinarian or emergency animal clinic as soon as possible to obtain a professional evaluation and necessary treatment.