Seasonal flank alopecia in ovariohysterectomized dogs.

Recurrent seasonal flank alopecia was recognized in 5 ovariohysterectomized female dogs. The dogs first developed hair loss between 1 1/2 and 4 1/2 years of age. The hair loss began in March or April (spring) and spontaneously resolved in July or August. The dogs were otherwise healthy, and no cause for the condition could be determined.