Causes of sunken lower back in cats:

1. It may be caused by the cat’s hunger. The volume of the stomach and intestines will be reduced, causing both sides of the lower back to look sunken.

2. It may be caused by the cat being too thin. Being too thin for a long time will cause the cat’s lower back to be sunken.

3. Cats poisoned by organophosphorus and other substances can cause digestive tract symptoms and can also make their lower back sag. They should be sent to the hospital for treatment in time.

4. It may be that there are parasites in the cat's body, and the cat has not been dewormed for a long time, causing the parasites in the cat to suck the cat's nutrients. At this time, the cat must be dewormed in time.

5. Folded-eared cats may have skeletal problems due to genetic problems, resulting in a sunken lower back.

6. If a cat has symptoms of lower back depression since childhood, it may be congenital, such as skeletal deformity, dysplasia, etc.