Two of my bucklings (7 wks old) have soft swellings where the jaw and neck meet. About fist size on one, and about 1/2 that on the other. They are drinking from a lambar with 5 doelings the same age...none of the doelings have it. I have had it on bottle babies before and it goes away after several months, but just wondering if anyone can tell me what causes it? Could it be from the way they drink? Or something else entirely?