Young Belgian Shepard dog?

I have a Belgian Shepard around 15 months old, I got him when he was 4 or 5 weeks old. As he was growing up, he's always been a heavy/stalky dog with long beautiful fur. When he got around a year old, he got real sick, Before he got sick he weighed almost 80 lb's, and dropped down nearly 10 pounds while being sick, He couldn't walk on his own. I had to take him out side and hold his hind legs so he could pee, and he would lay in the same spot for days, (I'd turn him over every now and again). It got to the point to where he was so sickly skinny and wouldn't eat that I had to force feed him, and use a syringe to force water down his throat, I took him to the vet and the vet said he had a very high white blood cell count, and that his body was fighting off infection. he vet couldn't tell me what kind of infection it was, as he said blood test's couldn't show it. He gave me antibiotics for my dog, which I gave to him. Before he got to sick to move, he started digging at his sides and back, until he was red, he even dug until he started to bleed in some cases. He lost a lot of his fur on his hip area and his sides. While he was sick he started to flake a lot, and a horrible smell started emitting from his body, My dad explained it was a sicking, horrid and smelled like death. after a few months, he has gotten better, He has gained some of his weight back, and has energy to run around and play like he used to have. However, although he has gained some weight, he is still very skinny and sickly looking, and The smell, though has gotten better, is still present. I have asked around for advise including vets. Which don't really show to much concern by the way, Their answers are Yeast infections or allergies, His fur has grown back, but he still digs at it and still makes it red with his consent chewing. I give him baths in oatmeal, salt, baking soda, oatmeal shampoo, medicated shampoo, etc. and it still doesn't do much for the smell or his digging of the skin... I have started to bathe him every 3 days, uming it'll knock out what ever is causing this problem.. I sure could use some advice with this, maybe some of you have experienced this? Any advice would be appreciated!