I am probably just being overly paranoid, but I noticed these little sores on his mouth this morning when he was sleeping on my lap. I am assuming it's just that his adult teeth are coming in and rubbing areas that aren't used to it. Also excuse that he has food on his face still.
They are called "rodent ulcers" according to my vet. Although if you google rodent ulcers, you will see MUCH more horrific pictures than that. Leo gets them from time to time, they are always that size or smaller, and never get infected. They just heal on their own and go away. They are always above his canine teeth on the top lip. The vet was worried that they can be present as part of an autoimmune disease, but I have never had much concern about them.
Yes, Anna has moderate allergies and gets one of these ulcers on an upper lip. I have started l-lysine regime with her and am doing more reading on immune support for her.
There are lots if good articles on natural care for these ulcers on the web. I want to try and keep her off steriods.