My job includes caring for an axolotl along with other amphibians and reptiles. I believe it is a male. About 2 months ago he developed a pinkish sore/growth on/in the left side of his mouth. It doesn't appear to have grown beyond what is in the pictures and hasn't lost any weight. Other than that, he seems fine and eats well. I'd like to find out what it is and if I should take any action. Help would be most appreciated .