Best thing for dry skin is water. If he tolerates baths well I would fill up the sink or tub to the point where he can still stand and doesn't feel the need to "swim". Have him stand in there for 10 minutes while cupping the water over his body to hydrate his skin. Then you can drain the water and bathe him. I'd use a moisturizing shampoo with aloe and oatmeal and then a deep conditioning treatment. You can microwave the conditioner for a few seconds to make it warm, then massage that all over into his coat. Wrap him in a warm towel for 10 minutes. Lastly, rinse rinse rinse with room temp water then a quick rinse of cooler water to seal the hair follicle. During the week, in-between baths, give him a spritz with diluted leave in conditioner (or just water if the leave in will make him too greasy) and massage it into his skin.
I wouldn't change his food just yet because its probably just dry winter skin he's suffering from (like most of us right now, my hands are so itchy from being dry).
Hope this helps.
__________________ Kellie  and  Morgan |