“I was hoping you might be able to help. I have two American Green Tree Frogs (Spike and Froggie). Spike is extremely skinny. We feed her (I think she is a female because she does not “quack” whereas Froggie seems to “quack” non stop) 3-4 crickets every other day and she is extremely active. Yesterday I noticed two marks on her back. They are right on top of the little bumps that I assume are a part of her legs (I hope that makes sense). They almost look like cuts, but don’t seem to be open sores. She also has developed dark spots around her mouth/nose. Any idea what this may be and what I can do?”
There are many ailments that can cause unusual blotches or markings to show up on frogs.
As you probably have noticed, green tree frogs naturally change colors depending on environmental conditions such as temperature and light intensity, so the first thing to consider is whether or not it may be related to the environment the frog is kept in.
Perhaps more likely and concerning though is that it could be a sign of disease. Bacterial and fungal infections can cause discoloration, especially when they are localized around a wound or particular injured area. These types of problems require diagnosis and treatment from a veterinarian.
My advice is to separate the two frogs in case it is an infectious disease. Take care of the healthy frog first so you do not spread anything around and monitor the tree frog with the strange coloration carefully. If you have an exotic animal vet who you use, contact them and they will hopefully be able to look at the frog in person and scrape, swab or otherwise sample the infected area as needed to determine if it is a disease or something else causing the change in coloration.