Yes, coffee is toxic for cats, more exactly the caffeine in coffee is toxic for cats in large amounts. A few licks of coffee or tea won’t kill your cat, but from 100 to 150mg of caffeine per kg of your cat’s weight will be lethal. Drinks like coffee, tea, Coca-Cola, and energy drinks consumed in large quantities by your cat can lead to caffeine poisoning causing restlessness and agitation, rapid breathing, heart palpitations, and muscle spasms. Caffeine can also be found in chocolate.