Looks like a food allergy and you feed beef one of the main causes of this fish and rice or salmon and potato dry mix walfcol do one its not cheap though.Also give the dog piriton one 3 times a day to help with the itch antibiotics wont do it.Also buy hibiscrub this helps too or bodyshops honey shampoo and conditioner works a treat used this on my bitch she had a lot of baldy bits when i got her