Hi I'm so sorry for you both its is awful to feel so helpless.I have used many times in my dog rescue Arsen.alb/sulph for mange in dogs and foxes.It is a homeopathic remedy that can be bought from Helios homeopathic pharmacy tel no 01892 536393 a few drops each day are put on food and it works.I also rub into the skin lavendar oil as this helps with secondary infection and soothes the skin.I have had dogs in the rescue with very bad mange and have treated them with nothing else but this, it does takes a few weeks to see an improvment but is much gentler on the skin than the washes.The other thing that I give them is a really good vitamin supplement as mange mites don't like a healthy skin so this does improve the general condition.I know that some people will say that homeopathic remedies can't work but animals can't fake it and this does work.A fox was given it at a feeding station and his mange was so bad that he had no hair left,the lady phoned to tell me that 4 weeks later he had a new coat coming through and his body had complete hair cover.Might be worth you giving it a go.