about a month or so ago we had a problem with my girl with a "lump" on her lower jaw. We took her into the vet and by that time the swelling was gone and everything seemed a-ok.. I have been a bit weirded out since then and I am constantly checking her jaw and every once in a while she will have a bit of a "lump" on her lower jaw.. It feels like the jawbone itself is swollen but it will go down and disappear just as fast as it showed up. Sometimes it will feel like it is not on the bone but on the fleshy part of her lower jaw. I have noticed that her collar has a pretty big metal clasp on it and I am thinking that maybe it could be from her collar swinging and hitting her chin time after time while she is running. It definately is loud while she is running with her tags swinging and the collar fits her a bit big so I am hoping that this is the culprit. I have taken it off of her for atleast a few days to see if her jaw will swell back up or not. I am assuming that it is nothing serious like a tumor or anything because of the swelling and then disappearing within a day or so. She is a very active puppy and shows no fear of injuring herself so she goes full blast no matter what she is doing. Anybody else have any experience with this? The collar is a rolled leather collar, but I think it may be sized a bit big for her as its on the smallest setting and I can almost slip it over her head still.. Anybody? I am worried something may be wrong with her!