I just got my mare and I rode her for about an hour that night, and in the morning I noticed 2 big bumps. The bumps were located where the girth was sitting, on her under belly. I felt them and they didnt feel like there was swelling (it wasnt hot). That was about 4 days ago and the bumps are just now getting smaller. I didnt notice any pain while I was riding, and I didnt see that she was in pain when I touched the bumps. What could this be? She is about 15 yrs old and she is a spotted saddle horse.