Cats can eat watermelon, but not too much.
Watermelon contains up to 90% water. A cat needs to consume 50-60ml of water per kilogram of body weight per day. Eating a small amount of watermelon can replace the cat's voluntary drinking to replenish its water intake. 
Secondly, watermelon is rich in vitamins, which can increase a cat's vitamin intake.
However, it's important to note that watermelon is considered a cold food in cats, and excessive consumption can upset their stomachs and intestines, easily causing problems such as vomiting and diarrhea. Furthermore, the high sugar content of watermelon can increase the burden on a cat's internal organs, potentially triggering chronic diseases like diabetes. Therefore, pay attention to the amount of watermelon given to your cat to avoid overeating and causing illness.
