My mom purchased a horse from a trainer. The horse had labored breathing and the trainer said he had had him to the vet and couldn't find anything wrong. The trainer suggested a 10 day course of penicillin in case it was a respiratory infection. My mom gave the horse 10 days of penicillin and the horse died on the eleventh day. She came out in the morning and he was laying down dead. It appeared that he died before he hit the ground because there were no signs of struggle to get up. The trainer had signed a contract when she purchased the horse that if the horse died or was otherwise extremely ill he would refund her money or provide her with another horse. Well, when the horse died this trainer disappeared and it ended up in court. When the judge heard my mom's testimony he told her that she killed the horse with 10 days of penicillin stating that she killed all of his good enzymes and bacteria. He told her that he has never before heard of giving a horse penicillin for that long and that she ultimately killed this horse. Could the 10 days of penicillin killed him? Is that too long to give penicillin?