No collar on her, when i noticed the hair loss i took it off & she hasn't worn one since (months), After reading up on this as much as poss i think it is quite possible she has a zinc defiecency, all the signs are there & it is common in english bull terriers, she has the hair los, reddening of affected skin, scaley crusty skin on legs, spots around mouth & can sleep for england.
I'm changing her to a raw wheat free diet, i've dosed her with advocate on the off chance it's mites that weren't picked up on the scrape, changed my washing powder & bought a 2kg powder form sa37 &