[bizzbeth]

Hey everyone,
I was petting Oliver (1 1/2 years old male yorkie) and on his right side near us hip but a little forward on the side of his stocmach/back there was a lump the size of a half dollar!!! It is stationary and I can press on it and he doesn't show any discomfort. I'm pretty sure it wasn't there yesterday!

Anyways... any ideas of what it might be? He's been going on short jogs for the past two days with my BF and me. Could it be a sore muscle/gland? I really am clueless in this department. The skin isn't broken and the bump is not red so I don't think it is a spider/bug bite.
Help?!