Q. my blue heeler is a little over 5 years and she has crusty hard knot that is itching her bad ,,that she has a hard time with it is centered on back
DAVID ELBEZE, DVM, MRCVS
A. This is probably caused by an allergic reaction. first of all make sure you flea your dog regularly every month with a high quality spot on (ex. Advantage) as fleas are by far the most common reason for these reactions.
If the fleas are not the problem, it could be an allergic reaction to food or an environmental factor. this is more complicated to treat and will sometimes require medications such as Steroids, anti histamines or cyclosporin in order to stop the allergy.