@bwnd4,
Theres a form of "dumb rabies" where the an imal just sort of has a fifty mile stare and acts listless, often just bobbing its head. Its never a good idea to take any wild animals in. You know he has sarcoptic mange and this can spread to other animals in the house (furry ones) .
Youre a good person for caring but sometimes we have to back off and let nature cull the sick and dying on its own.