Hi I have a friend with a tiger salamander (Ambystoma tigrinum) who has developed a wound on his head. He says it looks like a small scratch/bump. The friend has had this tiger for 15 years and recently went out of town and left him with a herp sitter. I don't believe the sitter was misting his enclosure or refilling his water. The friend was out of town for several weeks. He's currently in a 10 gallon quarantine aquarium with a screen top with coconut fiber substrate. He has a water dish cleaned regularly and filled with tap water. He's not using a water conditioner. The tank is room temperature so 75 to 78*F. The friend mentioned that his salamander is blowing bubbles of mucus. Here's a photo. It's the bump near his eye. He's acting normally and eating and pooping. Suggestions?