
My old dog has just been to the vet this week with something similar, he also had a very strong smell. His was hot spots and a yeast infection. The worst sore started quite small and within a few mins the dog had made it bigger by chewing and also made it bleed along with chewing all the hair out.
He has always been prone to hot spots in the summer, but nothing like this.
The vet gave him some tablets and a shampoo. The shampoo is to be used once a week and after his first bath in it he is loads better allready :) :)
Definately a vet job though - there are so many different skin complaints and causes. The sooner you can get the right treatment the better.