The methylxanthines in chocolate overstimulate a cat's nervous system and heart. Because a typical cat weighs only a few kilograms, the dose per kilogram climbs fast: what would be a minor exposure for a large dog can be a serious one for a cat. As with dogs, the darker the chocolate, the higher the theobromine content — baking chocolate and cocoa powder are the most concentrated forms.
Signs range from vomiting, diarrhea, restlessness, and increased thirst to a rapid heart rate, panting, tremors, and seizures in severe cases. Cats most often encounter chocolate through baked goods, desserts, or chocolate drinks rather than a bar itself. There is no antidote; treatment is supportive and works best when started early.
Sources
- Chocolate Toxicosis in Animals — Merck Veterinary Manual
- People Foods to Avoid Feeding Your Pets — ASPCA Animal Poison Control
This page is informational and is not veterinary advice. If your pet has eaten something risky, contact your vet or an animal poison control line right away.