I'm using homeopathic treatment for a family of 3 foxes. Mum & one of her cubs had mange, her other cub seemed not to have it.
Please seek professional advice before even considering conventional treatment, like you can get from the vets. It can be deadly to certain breeds of dogs like any with collie genes, other animals and even foxes if a fox overdoses on it. Easily done if anyone leaves treatment for more than one fox out in food.
Thankfully their mange was caught in the early scratching, restless and biting their rear stage. No clearly visible fur loss, just a small bald patch above mum's tail.
I initially used jam sandwiches to put the drops on, but they didn't seem overly keen, so quickly changed jam for unpasteurised, raw honey. The foxes have woofed this up every night. It's more nutritious for them too. eBay does large tubs at good prices. I always put more little sarnies out than there are foxes. Scattered around my garden to ensure all foxes get the treatment. Mange is highly contagious for foxes, so best any visiting foxes get a sarnie. So I put 8 small sarnies out each night.
I saw mummy fox a few days after treatment and she was looking a lot better. She was more relaxed and far less scratching.
I used to see her and her cubs out in the daytime frequently prior to the treatment.
Now, I don't see them in the daytime at all. Sarnies are always gone. Occasionally I've seen one of the foxes going under the laurel hedge to eat one.
They're now sleeping in the daytime presumably, relaxing after their night time walk.
So I'd say that despite my initial reservations, the homeopathic fox mange treatment has worked. Nearing the end of the 6 week nightly treatment now. Make sure the treatment continues for this time. I'm also giving it to my dog for the same time as a precaution in the same dose.
I'd use the homeopathy drops again. I got a 50ml dropper bottle from a known, reputable UK fox rescue that sells it on eBay. The first bottle I got was tiny and only lasted a few days or so.