I'd be interested to know what you guys are feeding your dogs. Some might be prone to getting hotspots anyway, but quite often, it's severe skin irritation from allergies also. Basically anything you see a commercial for or ad in a newspaper/mag. is junk! If you can buy it in a grocery/department store, it's junk! Half the stuff you can buy at Petsmart/Petco is junk! Definately try going to something that is corn/soy free for sure. Next alternatives are to remove chicken and wheat. Canidae is an excellent dog food. Natural Balance is a great food too and does have allergy formulas, so if your dog doesn't like one kind, try another, this brand is one of the few I know of that has more than one or two varieties (such as a general all life stages and a senior). GO Natural is a new food that's really good as is Evolve. If money is an issue Chicken Soup for the Dog is a good food to try and about the lowest priced one. There are some others that are great as well, but these are the ones I know of personally that are definately corn/soy free, and some wheat free.
I had a lady call me a couple weeks ago and she reserved a GSD pup from our litter. She also told me that her current GSD was very itchy and she thought it had food allergies, which she told her vet, so they advised switching her to Purina Beneful of all things. What crap! This is complete junk, loaded with allergy causing junk. The vet's next recommendation was Science Diet, also complete junk. My vet recommended switching my little housedog that has a slow metabalism and likes to sleep, hence a bit pudgy even on a diet, to Science Diet Lite. I laughed at her. Their filler (or used to be at least) is peanut hulls, so the dog can eat more and not have the calories. What a joke. All Science Diet is junk also, but vets recommend it cause they get a kick back from it. Iams is junk now too since it's gone to grocery stores, they changed the formula and our dogs started getting awful from it 3 years ago when we fed it. Iams is the home to Eukenuba, which is equal to what the Iams was now. It's better than a lot of other feeds, but still has corn in it. Anyway, this poor allergic GSD was eating Beneful for it's allergies, as recommended by the vet and getting massive doses of Prednisone daily. She immediately went out the next day and bought Natural Balance, quit the Prednisone (which is steroids, can cause serious side effects) and I talked to her again last week and the dog is doing wonderful already!
Look at your dogs food and don't be afraid to spend the money on the good stuff. Dog Chow recommends feeding 10 cups a day I last knew to a 100 lb dog. Our male GSD gets 4-5 cups a day of Canidae. Less food goes in = cut your feed used in half = save money = less poop coming out = less shoveling!