What on earth could it possibly be!? My Nubian has almost a tennis ball size low on her esophagus, it is kind of soft and can be moved around somewhat. On the first of this mo we put her in the back of the truck after being bred elsewhere and a hornet was in there so thought it could have been a sting but that was over two weeks ago & it has gotten larger. Its not uncomfortable or unusually warm. Its too low to be bottle jaw. Last yr CAE & CL tested neg. When she gets grain I do have to give it in small amounts or she will choke on it. Pooping peeing & eating hay fine. Waiting on call from vet. Thanks so much for your input.