Reasons for cats with bad breath and not eating:

1. The cat may be infected with calicivirus. When a cat is infected with calicivirus, there will be symptoms of oral ulcers, which will cause the cat to be in pain, unable to eat, and have bad breath.

2. The cat may be suffering from stomatitis. Stomatitis in cats can also cause gum pain. Cats are reluctant to eat on their own. Bacteria multiply in the mouth and cause bad breath.

3. The cat may be suffering from digestive tract disease. When a cat has constipation, diarrhea, or eats indigestible food that causes flatulence, food accumulation, etc., the smell of fermented food in the intestines and stomach will also be emitted through the mouth. It will also affect the cat’s appetite.

4. The cat may be suffering from diabetes. When a cat suffers from diabetes and reaches the stage of ketosis, the mouth will smell like rotten apples, and the disease will also cause the cat to have a loss of appetite.

5. The cat may have dental calculus. Severe dental calculus in cats can lead to gum recession, gum inflammation, etc. It can also cause the cat to be in pain and reluctant to eat, and the dental calculus will emit a strong odor.