I have a 5 year old pure bred blue merle, male. He is shedding in clumping around his left hind quarters and his tail, but nowhere else.  There seems to be little raised bumps on the affected area.  I have changed his food from kibbles and bit to a more organic mixture of chicken and corn a little over a week ago.  He does have an oder to him as well.  He is still losing tuffs of fur.  He doesnt seem to be in any pain or have any iritation in the area but the affected area is getting bigger.  How long should it take to notice any difference once diet is changed?  Should i be using a topical treatment on the area?  Thanks for your help we really appreciate it.

not my breed but if use this quistel shampoo it might help.check out the web site to find where you can buy it from hope this helps and good luck
www.quistel.co.uk

Really you should get him to the vets, no one on here can diagnose what might be wrong and there are so many things it could be, it could be hormonal (thyroid etc.) or it could be an infection or it could be mange, either way it would need veterinary help to sort out - and if its mange, the sooner the better ;) ;)

let us know how you get on

Regards
Dill