The reasons why cats vomit yellow water and refuse to eat: 1. It may be due to long-term hunger. 2. It may be due to overfeeding. 3. It may be caused by the cat being infected with internal parasites. 4. It may be caused by the cat's illness, such as inflammation of the gastrointestinal tract, pancreatitis, etc., which can cause the cat to vomit yellow foam. 5. It may be that the cat is infected with feline distemper virus or other infectious diseases, causing vomiting of yellow water.

How to treat a cat that vomits yellow water and refuses to eat:

1. It may be due to long-term hunger. If a cat has not eaten for a long time, excessive gastric acid secretion will cause vomiting of yellow water. It is recommended to feed the cat an appropriate amount of glucose or nutritional paste, and feed it regularly and quantitatively every day.

2. It may be due to overfeeding. If the cat is fed too much, especially too much cat grass, it will cause yellow foam. At this time, the cat needs to appropriately reduce its intake.

3. It may be caused by the cat being infected with internal parasites. It is recommended to use internal anthelmintics immediately for deworming.

4. It may be caused by cat illness, such as gastrointestinal inflammation, pancreatitis, etc., which can cause cats to vomit yellow foam. At this time, the owner needs to take the cat to the pet hospital for diagnosis and treatment in time.

5. It may be that the cat is infected with feline distemper virus and other infectious diseases, causing vomiting of yellow water. It is recommended to consult a doctor immediately for treatment with antiviral drugs.