Our neutered 4-year-old Irish greyhound, whom we adopted a couple weeks ago, has a lump about the size of an egg (if it were mostly submerged) on his inner thigh, a couple inches from his genitals. Unfortunately, I don't see any way to add a photo. He doesn't limp or seem to be in any pain, and there is no record of a previous injury. The lump is neither hard nor soft, but somewhere in the middle. He marks a lot, but that could be because he's still new. Does anyone have any ideas? Thank you.