Milk
Caution
Verdict
Not poisonous — but most adult cats are lactose intolerant.
Toxic principle: lactose (most adult cats are lactose intolerant)
Source: ASPCA
Verdict
Most adult cats produce insufficient lactase, the enzyme needed to digest lactose (milk sugar). Drinking cow's milk can cause digestive upset including diarrhea, vomiting, and gas. Kittens can digest their mother's milk, but cow's milk is not a suitable substitute. Some cats tolerate small amounts of dairy, but many don't. Goat's milk has slightly lower lactose but is not guaranteed safe either.
Symptoms to watch for
- • diarrhea
- • gas and bloating
- • vomiting
- • loose stool
What to do
If your cat drank a small amount of milk and shows GI upset, restrict food briefly and provide water. There is no emergency, but avoid giving milk regularly. Cat-specific lactose-free milk is available at pet stores.