my cat had a cut on his toungue still helaing up
thanks Jade for that great info!!.....I didn't know that caili virus could also cause mouth sores.
Sissy, another possibility is EGC or Rodent Ulcers these can appear anywhere on the body even the mouth.
Check out this link, it even has some good photos to compare with.
http://www.marvistavet.com/html/body_eosinophilic_granuloma.html
I do suggest you don't repeat the cortisone injections, more than 3x a year can bring about another health problem such as diabetes....its better to treat the cause(once found) rather than to treat the symptoms...
the best of luck to you and kitty, keep us posted.
Hi Sissy and welcome. First, human tuna should not be given to kitty due to the mercury in it...at least, not too much. Using it to get a pill down is one thing, but kitty needs cat food for the nutrients.
My first thought is I wonder if your cat is eating out of a plastic bowl? This can cause feline acne. This could also be herpes. The info below is from an earlier thread that I copy and pasted. Hope it helps some. I'm not suggesting the info below is exactly what your cat has, just an idea.
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Viral infections - the most common one that causes mouth sores, drooling, and foul breath is a serious infection called calici. This can cause ulcers on the gums, tongue, lips, roof of the mouth, throat, and lungs. This is one of the two most dangerous viral upper respiratory infections. It commonly leads to bacterial infections that require antibiotics to cure. Pneumonia is also a somewhat common complication. Most cats will stop eating when suffering this infection due to mouth pain. Adult cats usually aren't as affected as kittens are, but this is a tough infection for cats of every age and can be fatal if not managed. Hospitalization is needed from time to time if the cat will not eat. Calici is often carried for months, even years, and may cause milder flare ups throughout the cat's life.
The other most dangerous upper respiratory infection that can cause these symptoms is feline herpes. This one doesn't cause sores as often as calici, and it usually produces copious nasal and eye discharge. Treatment is the same as for calici - antibiotics to fight bacterial infection, as well as supportive care with vitamins and subcutaneous fluids if needed. L-lysine is also recommended to use with herpes patients. 500mg a day is the effective dose.
Autoimmune disease is caused by the body's immune system attacking the body's tissues. The mouth is one of the more common places where autoimmune disease is manifested. When it causes sores in the mouth, it's called stomatitis. Stomatitis is especially dangerous because it causes periodontal disease, which may lead to organ failure. Stomatitis can sometimes be managed with antibiotics to prevent infection, or oral steroids to reduce inflammation. Ultimately, most stomatitis patients will need to have their teeth removed. This is because the ligaments that hold the teeth in place are usually the tissues being attacked. Once those ligaments are removed, the disease resolves. I have many cats who are toothless, and they eat both hard and soft food just fine. They actually feel much better once their teeth are pulled.
So definitely seek the advice of a vet. Regardless of the cause, sores in the mouth need to be promptly treated.