Bald Patches on Lab Dog

Question
Dear Dr. Gotthelf,

my Labrador Retriever Female (pure bred, as far as i know) is exactly 1 year old now. Over the last few weeks she is losing her hair on her hind legs and the bald patches are getting bigger and bigger each day. Otherwise she is in very good health. My Vet doesn't know what it is so i was hoping you might be able to help me. Our vet prescribed 'Derm Caps 100 plus' for her but this doesn't seem to help with the hair loss.
she got all her shots plus 2 shots against lime disease in the last 2 months. She is mostly an outdoor dog - we have a big fenced in back yard (we live in CT) and  thought she might be allergic to something she lays on outside(gras, soil, pillow, doghouse)or the shots. Also the weather was very hot during the last weeks - could it be just normal loss of winter fur?
Her diet consits of dry food (iams large breed puppy) plus an occasional 1/3 can mixed in with her normal food.

Here are some pictures

https://fotoalbum.web.de/gast/elvirajibben/Mixie

but it looks worse in real.

i hope i gave you all the information you need. i really woud appreciate your help.
Thank you.

Best,

Elvira

Answer
It takes a month or two for the Derm Caps to work.  If it is really itchy, then it could be one of a few things.  It could be an allergy to something she is laying on causing the itching.  It could be something like sarcoptic mange or some other type of insect problem, it could be an allergic  reaction to something else in the environment.  Ask your vet to check for these things and ask the vet if your dog can have a shot of some cortisone to see if it stops the itching and hair loss.  Continue the Derm caps.   They really help make the skin less sensitive to insult. Shampooing twice a week often helps as well.