Image Quiz: Itchy plaques in a German shepherd

A 13-year-old spayed female German shepherd was presented for evaluation of pruritus localized to its legs and trunk of one month's duration. Historically, this dog had no previous skin or ear problems. A two-week course of cephalexin with a tapering dose of prednisone and then a 10-day course of enrofloxacin had failed to eliminate the itch. On physical examination, multiple alopecic, erythematous plaques on the forelimbs and the caudal lateral hock were present (see below).

What would your next step be?

a) Swab one of the lesions, and send the sample for a bacterial culture.

b) Inject the lesions with methylprednisolone acetate.

c) Obtain a fine-needle aspirate of one of the lesions.

d) Send the dog home with an Elizabethan collar and clindamycin.