Canine Psora?

My dog is an intact male Newfoundland, 5 1/2 years old. I picked him up in Michigan when he was 15 months old, the day I picked him up I noticed he was quite small for the breed and very timid, had a slight fear aggression, he had a hot spot as well as an ear infection, his feet were inflamed between his toes and he was constanly licking and chewing at them...... Four years later we are still dealing with the same problems, he has been on antibiotics for most of his life which seem to suppress most of the medical symptoms as long as he is on the meds but come back as soon as he is off. It has been suggested that he be tested for allergies but the cost of the test has deterred me. In the past I have tried several different diets with none making a difference other than causing extremely loose stools (he has a severly sensitive stomach).

After talking with a friend about the issues we have been dealing with she suggested I look into homeopathic remedies, and as much as I am a sceptic, I was willing to give it a try. I did a few hours of research on the internet and decided to buy Sulphur, Belladonna, Calcarea Carbonica, and Mercuruius Vivus, all 30C. I received the products on 4/2/13, started giving the Sulphur that day (nothing else), on 4/6/13 I started noticing several hot spots on his muzzle (normally his hot spots are at the base of his tail and quite a bit larger), also noticed that the foul smelling discharge from his ears changed from almost black to a thick yellow pus. From my understanding (which is about zero), these are signs that things are working, I have not given anything to him since about 3pm on the 6th.... I am now wanting to know if this is, indeed, a good sign and would also like some guidance on what I should do from here.