Can dental or tooth pain make a cat stop eating?

Yes, and it is one of the more common hidden causes of fussy or reduced eating in adult cats. Between 50 and 90 percent of cats over four have some form of dental disease, and pain from a bad tooth can be enough to make a cat back away from the bowl. Watch for chewing on one side, dropping food, pawing at the mouth, bad breath or a sudden preference for soft food. A vet exam, often with dental x-rays under anesthesia, is the only reliable way to diagnose and treat.

Source: Cornell Feline Health Center, “Feline Dental Disease”