The development of cystic endometrial hyperplasia in the bitch following serial uterine biopsies

Serial uterine biopsies were performed on two bitches during three oestrous cycles. The uterus was biopsied once in one other bitch and twice in another case following exteriorization and palpation of the uterine horn on four occasions earlier in the cycle. Following the serial biopsies both bitches developed a vulval discharge for a duration of 8-21 days. This first appeared between metoestrus days 14 and 30. By the 5th week after oestrus the uteri of both bitches developed cystic endometrial hyperplasia with inflammatory cell infiltration which regressed spontaneously. This lesion did not develop in the two other bitches, and it may have been caused by the surgical interference with the endometrium during the period of luteal development.