Hi, I am in the unfortunate and heart breaking position of having a vizsla who was 6 3/4 years old when the symptoms started which included the immune system breaking down, upset tum, sores on his body, hair loss and muscle wastage on the head. It is really important to get steriod intervention asap, the first vets I went to did not believe in them, (create other problems!) but I changed vets 3 months later and have subsequently found out, he was dying and if I had not have changed vets he would most certainly not be here today. He is fine, muscle tone does not come back on head though, still on steriods every other day, does get eye infections, regular bathing of eyes, he had a lost a lot of weight but he is back to form and full of bounce to the point that when I say he is 7 people oftern think 7 months not years!! Not sure what lies ahead but could not give up on him then or now, will and would be brave if I thought his quality of life had diminished to the point that it would be kinder for him.
I stress from my experience the auto immune drugs did not work and I had spent nearly £4,500 before I changed vets and got him on steroids yes they might have side effects long term we will have to wait and see, the other route would have left me without a dog and a dog that was suffering and refusing to eat the soya based diet that he had been put on, now on fresh lamb mince and potatoes or fish and happy!
If you want to more about the disease there is this link that will help you: