Cats can eat ham, but only in very small amounts and as an occasional treat. Plain, cooked, lean ham without seasonings or additives is generally safe in tiny portions, but ham is high in sodium and fat, which can cause digestive upset, pancreatitis, vomiting, diarrhea, and other health issues if consumed in larger amounts. Ham cooked with onions, garlic, or seasonings is toxic to cats and should be avoided completely. Raw ham and ham bones are also unsafe for cats. Overall, ham is not an ideal food for cats, and it is better to rely on balanced cat food for their nutritional needs. If ham is given, it should be lean, cooked, unseasoned, and offered sparingly, while monitoring the cat for any adverse reactions.