What kind of mange? Sarcoptic or demodex? both can be treated this way but if it is Sarcoptic mange it is contagious to you and other dogs. What did the vet say exactly?
You can treat mange from home and here are a few ways to do it. How much does she weigh?
You need to get some ivermectin from a feed store it will look like this or it could be another brand. It will range in price from 23-50 dollars depending on where you get it from. Because of the laws in the us the vets can only tell you to use it orally once a week. Studies have been done and in other countries it is given daily for 2-3 weeks. I have had success with advice from my vet off the books with using it every other day for 3 weeks. The dosage is 1/10 cc per 10lbs of body weight, if you can not calculate it by yourself then post her weight and I or someone else can do it for you. everything you need including syringes will be sold at the feed store or you can order them at lambert. It tastes horrible so I mix it with a little wet food and give it orally. It burns if you do it subQ so it is easiest to give it orally.
Ivermectin Injectable, 50 ml - Wormers - Lambert Vet Supply
Because your dog is so bad you need to also dip your dog
You should dip your dog in prolate
Prolate, 1 qt - Insecticides - Lambert Vet Supply
Prolate = topical insecticide for livestock
You can purchase at Prolate®/Lintox®-HD from Lambert Vet Supply
It is 1 ounce of Prolate to 1 gallon of water.
Put into a spray bottle to spray on body
Use a sponge to put around eyes, nose, mouth and private area.
3 x a day for 2 weeks
2 x aday for 1 week
1 x aday for 1 week
You then simply spray down your dogs being careful not to get it in the eyes or mouth of you or your dog. You can also use the spray as a kennel spray to eliminate all mites located in the kennels, dog runs, dog houses, or other sleeping areas. Not to mention also you house if the dog is in the house
The Prolate dip/spray works wonders on sarcoptic mites, ear mites, lice, and even ticks
Then your dog should be on antibiotics because of the skin infection that is going on from scratching. You should put her on Cephalexin you can get it without a prescription it is called fish flex. It is the exact same medication just bottled for fish use, it really is a scam who they do that!
You will give her 1 pill 2x a day and I would do it for 14 days because she is so bad. How much does she weigh again? I need to make sure the dosage is right but get the 250 mg pills they are cheaper and good to keep on hand anyway.
Fish Flex, 250 mg Cephalexin x 100 Capsules, Non-prescription - Non Prescription - Lambert Vet Supply
Next for her itching you can help her by giving her Benadryl. You will give her 1-2mg per 1 pound of body weight. The pills you buy at the store are normally 25mg pills so if she weighs 40 lbs you can give her 50mg which is two pills. You can give this 2 times a day and the reason it helps is because the body releases histamines into the system when they scratch the skin like that. ( It is more technical than that but you get the point) Benadryl helps with the itching for Mange while they are going threw the healing process.
Mange is an immune system issues so you need to build the immune system back up so do not give her anything like steroids or vaccines while she is recovering. Those will weaken her immune system and make recover longer.
I have cured many dogs with mange and some as bad as your girl, it just takes time and you have to be dedicated to the treatment. In about 2 weeks you should see some improvement and in 4 week the improvement will be really noticeable but it takes time and you can't skip a treatment. good luck and let us know if you need more help.
ps you can buy all this at one place and save your self hundred of dollars vs letting the vet treat but if at anytime you think the vet needs to see your dog then take them. Follow the dosages carefully and you should be fine.