Cats cannot have chocolate as it is toxic to them. Chocolate contains chemicals called theobromine and caffeine, which cats cannot process. Even small amounts of chocolate can cause severe health problems, including vomiting, increased heart rate, seizures, and can be fatal. Dark chocolate and baker’s chocolate are the most toxic because they have higher levels of these chemicals, but all types of chocolate—including milk and white chocolate—should be avoided for cats. If a cat eats chocolate, a veterinarian should be contacted immediately as it can be a life-threatening emergency.