I completely agree with Ruff and Pit Chick. Especially as an older dog with hair loss, he needs to be inside where it's warm and you can monitor his health more easily. He may also be experiencing stress outside which could aggrivate skin problems, along with the cold aggrivating possible arthritis. Your other dogs should also spend time inside, there is no such thing as an outside dog, and it isn't fair for them to spend 24/7 outside subjected to cold/heat. Even if they are farm dogs, Aussies and Sibes and Dobermans are all very people-oriented dogs who probably would love to have inside time in the warm house with their family. Just allowing him to sleep in a crate inside might help. I don't know a lot about skin problems, I would try other foods to see if this could be food allergies. Look for lamb-based kibble, like Solid Gold Hund-N-Flocken. There are also a lot of holistic medications and creams (some available from Solid Gold) to help with skin problems.