There are many reasons for cats to vomit yellow water. If they are in good spirits and have a good appetite, it is not a serious problem. The conditions for cats to vomit yellow water are: 1. The cat licks a large amount of hair and forms hair balls in the body. If it cannot discharge it in time, it will vomit yellow water; 2. The cat has not been dewormed for a long time, and internal parasites cause the cat to vomit yellow water. ; 3. Accidentally eating spoiled or off-flavored food may lead to vomiting of yellow water due to indigestion.