Methods to remove bad breath in cats:

1. Brush teeth regularly. Pay attention to using a pet-specific toothbrush. The toothbrush should be softer and the toothpaste is edible. If the cat does not cooperate, you can give the cat a pet-specific mouthwash.

2. Go to the pet hospital for teeth cleaning. If your cat’s tartar is very serious, you can take your cat to a professional pet hospital for teeth scaling or teeth cleaning.

3. Grind the cat’s teeth. You can use polygonum or teeth-cleaning biscuits, etc., which can clean the cat's teeth while chewing and playing.

4. Supplement vitamins. When a cat lacks vitamin B, it can cause bad breath. Owners can supplement vitamin B directly to cats, or they can supplement it through food.

5. Improve your diet. In terms of diet, be careful not to give cats human food. Do not give cats canned food, cat bars and other soft foods frequently. Cat food should still be the main food.