Causes
Normal hormonal changes after the season. It is part of the bitch's biology; in some it is very pronounced.
Diagnosis
Diagnosis is based on the clinical signs and the timing (weeks after the season) plus ruling out a genuine pregnancy.
Treatment
Mild cases resolve on their own within 2-3 weeks. Avoid stimulating the mammary glands (do not milk them, sometimes an Elizabethan collar helps). If it is severe or recurrent, the vet may prescribe treatment. Spaying prevents it in the future.
Prevention
Spaying prevents recurrent pseudopregnancies.

