A while ago I posted about how to improve my sheltie's coat. I read about how winter can really help coat come in. The only problem is that we heat with wood, so our house gets nice and toasty in the winter. Has anyone seen substantial improvement in their sheltie's coat during the winter? My sheltie doesn't have an undercoat- is it possible he could develop one during the winter? Some of you mentioned that your shelties spend a lot of time outside during the winter- how long should mine spend outside if his coat is going to improve? Advice appreciated. Thanks!