Today was the first time I have been able to check my mustang's udders to see if they need to be cleaned etc. I found a hard, almost baseball size lump way back and up between her teats (not actually in her teats). Of course I googled, and everything is pointing me towards tumors etc. I am completely freaking out. The vet is coming out Tuesday afternoon for routine dental and vaccines, but should I have him come out sooner? What could this be? It doesn't seem to be painful, or hot. Other than that there are no changes in her behavior at least, and aside from she seems to be a little bit more difficult keeper than she did this time last year, no other changes. She started dropping feed last week and seems to be having trouble chewing her grain properly, so I assumed it was related to needing her teeth floated and examined in case there are any other mouth related issues. Has anyone ever found a lump like this before?