I have just found out my baby boy Max has this and am devastated :'( - he is only 4 yrs old, and a beautiful Long Coated GSD
From what my vet said, and also reports i have read on so many websites, which actually all seem to be a bit old, highlight the severe side effects of those heavy drugs; anorexia, vomiting, lethargy, seizures, lameness + heavy hair loss. One of these drugs has been banned here in Australia so i would have to get it made (thru my vet) to then be prepared for the return as there is no guarantee how long after you do the course that it can all reoccur, could be just a month after it is finished or it could be a year, but it is incurable, so it will be back.
Do i put my baby thru that? as if what he is going thru now isn't bad enough, which breaks my heart or do i chose steroids - for me its quality of life for him.
Though every dog is different, I would like to hear the experiences of others, is there any good news out there?
His 2 sisters (not actually related) also ask your help, as he really doesn't want to play much anymore which makes them sad, they too are L/C GSD

Marilyn

A friends GSD (same age at onset) had cryosurgery, and it came back, she then managed the issue with Echinacea supplements and using aloe vera gel on the lesions. 

She was advised this course by a mutual friend who had several Leonbergers develop the condition and surgery had been non curative long term.

She also ensured he did not get constipated.

He lived comfortably until 13 years.

I had a 4 year old who had radical chryo surgery, and also had his anal glands removed. He never had a recurrance and had no other problems such as incontinence etc. That's the route I would go if I had another dog with it-- with a trusted vet.