Hi. We've had sheep for 6 years . Our first sheep are now approximately 12 years old. We have a mixed herd of baby doll southdowns and Cormo Mixes. We have them for the wool, and we just love having them around. However, we've noticed 3 southdowns with bald spots. I've attached a photo. We also have sheep with wool missing around their necks? Any ideas on what this could be?