428 DISEASES/DISORDERS
(a)(b)Fig. 28.11.Hypothyroidism in a 9-year-old female-spayed golden retriever before (a,b) and after (c,d) supple-
mentation with L-thyroxine. Prior to treatment, the hair coat appeared thinner and lighter in color, with alopecia
affecting the dorsum of the tail. After treatment, the hair coat has returned to a normal color and thickness, and
hair regrowth on the tail is evident.