Cat Mouth Hair. I think every pet owner has occasionally swallowed their fair share of animal hair, it goes with the territory. This is due to the barbs on their tongue.
When your cat is grooming themselves, they are constantly picking up any loose hair on their body. Stomatitis is inflammation of the mucous membranes in the mouth that extends deeply into affected tissues. While hairlessness is a feature of some breeds (e.g., sphinx, elf, delf cats), there is a genetic mutation that makes this type of alopecia possible in any cat breed.