Foods that cats cannot eat:
1. Cow's Milk: Cats cannot drink cow's milk because they lack the enzyme to break down lactose, just like some people are lactose intolerant. Drinking cow's milk will cause vomiting and diarrhea. Similarly, cats will also experience diarrhea after drinking cow's milk. It is recommended to give cats goat's milk instead.
2. Onions: Onions contain a pungent component that can kill red blood cells in cats, causing irreversible damage to their bodies. 
3. Raisins: Cats may vomit after eating raisins, and excessive consumption over a long period can lead to kidney failure.
4. Chicken bones and fish bones: These can easily injure the throat or digestive tract, leading to loss of appetite.
5. Abalone and snails: can cause dermatitis.
6. Sweets: can cause heart disease and dental plaque; chocolate can poison cats.
