What are the reasons why cats are too thin:

1. Insufficient diet: Cats will lose weight when their diet lacks nutrients or their caloric intake is insufficient. Solution: Provide your cat with high-quality cat food that includes all essential nutrients. You may also consider using supplementary food to increase your cat's energy intake, consulting your veterinarian if necessary.

2. Digestive system problems: Digestive system problems may cause food to be unable to be fully absorbed, metabolized and utilized, resulting in cat weight loss. Solution: Consult your veterinarian for an examination to look for and resolve underlying gastrointestinal problems.

3. External parasites: External parasites such as fleas or tick toxins can cause cats to consume a lot of energy, excrete a large amount, and eventually lose weight. Solution: Help pets eliminate parasites regularly, such as using appropriate insecticides, insect-proof collars, etc.

4. Disease problems: Some diseases may also cause cats to lose weight, such as thyroid problems or cancer. Solution: Consult your veterinarian for an examination and follow your veterinarian's treatment plan.

5. Hairy bulb syndrome. Cats like to lick their fur and eat the hair into their stomachs. When the hair accumulates in the intestines and stomach, gastrointestinal absorption will be affected. Feed hair removal cream.