The reasons why cats keep vomiting brown vomit:

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. It is recommended to feed the cat an appropriate amount of glucose or nutritional paste at regular times and rations every day.

2. It may be due to overfeeding. If the cat is fed too much, especially too much cat grass, it will cause vomiting. At this time, the cat’s intake needs to be appropriately reduced.

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. Cat vomiting is one of the main symptoms of acute gastroenteritis. It is mainly caused by cats eating spoiled and inappropriate food. Vomiting is usually accompanied by diarrhea, fever, and lack of energy. Vomiting is mostly persistent, and the vomitus is food residue and gastric juice. In severe cases, the vomitus is yellow-green or brown. At this time, the owner needs to take the cat to the pet hospital for diagnosis and treatment in time.

5. The cat may be infected with infectious diseases such as feline distemper virus and cause vomiting. It is recommended to consult a doctor immediately for treatment with antiviral drugs.