Oh, goodness, that looks so awful. Poor dog!
I know exactly how it feels to have a dog that has constant skin problems.
At first glance, I immediately thought flea allergy.
The lower back is a classic place where this manifests itself.
All it takes is one flea bite, and one bite turns into the kind of sores you described and that are visible on the dog. Those are now infected, because they are itchy and so the dog will not leave them alone, and you have a full blown chain reaction, even if the flea is long gone.
The first thing I would do is stop the allergic reaction. I would put the dog on Zyrtec, once a day, for at least two weeks or until this calms down.
Topically, it needs to be kept clean and dry, so that the infection, whether it is fungal or bacterial, subsides and the dog can regrow his hair. The best shampoo I have found, and I think I've tried at least 10, is Malaseb.
Malaseb is good because it doesn't matter whether the infection is bacterial or fungal, it will take care of either.
The shampoo needs to be applied every other day, and left on each time for 15 minutes before being rinsed off with an apple cider vinegar rinse.
Because it is difficult to do a regular shampoo, I put about a teaspoon or two and just enough water to make a soapy solution, Then I dip a clean washcloth in this solution and put it on the dog's skin. Leave on for 15 minutes, then come back with a clean washcloth dipped in a solution of a pint of water to 1 teaspoon of apple cider vinegar. Do this until the soap is gone. Dry the skin thoroughly.
Microfiber towel works best.
Now you need to apply something to treat the sores. I have had a really good results lately with Wonder Dust. It seems to feel really good, because I get the swishing wagging tail when I apply it. Keep in mind that it is gray in color, so be careful not to mess up your carpet when you put it on. This says ointment, but it's a powder.
Also, Tough Seal is wonderful to seal the wounds, and something about it makes the dog leave it alone. I use this at night.
This will not go away quickly, but given that you have been working on it for two years, perhaps trying a different regimen might make a difference.
I watch my dog's skin very carefully, and treat things as they pop up, and I pretty much have given up the idea that his problems will ever go away. It is an ongoing process, but I do my best to manage it and hopefully you, too, will be able to keep it under control.
Last edited by Sunflowers; 05-23-2015 at 04:07 PM.