Cat tongue ulcers may be caused by inflammation, injury, lack of oral hygiene, or lack of vitamin B. Cats need to be treated in time to avoid aggravation of the condition. First of all, you need to improve the cat's diet, feed it some light wet food, and also supplement the cat with vitamin B. Observe it for a few days to see if it improves. If it does not improve or the ulcer becomes more serious, it is best to send it to a pet hospital for treatment immediately.