I have two chickens - one black australorp and one white leghorn - that were sick about 6 weeks and 4 weeks respectively. They had some sort of ailment - not sure what but it was definitely contagious and killed a third girl in the week between the others being scik. The two surviving girls received penicillin for 3 and 4 days - one of them from the vet, the other from me. Neither girls have resumed laying, and the white legorn's comb has become tough, kind of yellowy red in color, and it stands straight up now as opposed to the 50's combover look. Are these normal longterm reactions to penicillin?