Last year I noticed Bo had some hard lumps right behind his jaw. I figured it was swollen lymph nodes, and didn't think anything else of it. When we moved the horses into the boarding facility where we are now at, I had to put the horses in quarantine. The vet did a full check up on both horses, and mentioned that Bo had melanomas under his tail. Anyway, while he was checkin Bo out I had him check out the lumps. He said it was just swollen lymph nodes. Here it is now six months later, and he still has those lumps. Doing some research, I found that once melanomas enternalize they go to the area right behind the jaw. Im concerned that this is not just swollen lymph nodes like I initially thought. I am setting up an appointment for a different vet to check him out. In the meantime, could you give me a guess as to what this is? I realize it is hard to see, with him being a grey horse, but I did the best I could getting pictures.