There are things other than Ivermectin that can be used for demodectic mange. I always used goodwinol ointment. There also are some natural treatments that might work, but I don't have any first hand knowledge regarding their effectiveness - apple cider vinegar, lemon juice, lemon juice mixed with witch hazel - are some of the ones I've heard suggested. Also, boosting his immune system will help. As for acorns, I had a dog that loved eating them and she got sick with diarrhea and vomiting from that. Raking them up and keeping her away from any parts of the yard where there were too many went a long way in helping that problem. When I had a dog who wouldn't eat, after she went 4 days hardly eating anything at all and was beginning to lose weight, what I did was mixed things into her food -- but I didn't pick up her unwanted food, make it tastier and return it. I would offer something tastier later in the day in order to prevent her from associating it with having refused her food. I'm glad Jack is eating again.