I was hoping to get some responses back, but I don't want you waiting too long for an answer either. There are several causes for itching in dogs.
It could be ringworm, mange, or possibly an allergy. Treating any problem without knowing for sure what it is causes a delay in the treatment of the real problem if your first guess is wrong. Below are websites on Ringworm and mange that will go into more detail on these conditions.
Here is a website on Ringworm:
Here is two on Mange.
You can read up on allergies here:
A lot of dogs have a reaction to ingredients in dog foods including beef and other meat sources, so you may want to switch dog foods and use the elimination method described on the following website if the two dogs are closely related. .
It may take several weeks to see improvement after the change of food. You may also give your dog Benadryl up to 2mg per pound every 8 hours.
There might be a secondary skin condition in addition to the allergy such as staph dermatitis or yeast dermatitis. Staph usually occurs on the lower regions of your pet and tends to have small pimple type bumps. Shampoo containing Chlorhexiderm and/or Oatmeal can help with this condition though it does not cure the allergy. Yeast typically shows as a greasy area that has a sweet musty odor. Sometimes the skin can become inflamed, darker and thickened due to itching. Yeast likes areas such as between toes, armpits and ears. Selsun Blue Shampoo can help with Yeast dermatitis. When shampooing, lather and leave on 15 minutes before rinsing. These shampoos are not meant to be a cure, just a relief until your pet can see a Vet.
Given that it is the dog's with hair that are having the issue, I'd investigate the possibility of fleas or mites since the fleas could hide in the hair and mites live in the hair follicles. For fleas try washing them in dawn dishwashing liquid and leave the lather on for 15 minutes before rinsing. If it seems to help, then fleas could be the cause since dawn will kill live fleas. It won't help eggs hatching but might help you pinpoint if fleas are the problem. If they are, you will likely have to get rid of them in the house as well.
I hope this information is helpful to you. If you would like any additional information or have more questions please don’t hesitate to press the reply to expert or continue conversation button so I can address any issues you still have . If you do find this helpful, please take this opportunity to rate my answer.