Experimental Production of Canine Pyometra by Inoculation with Escherichia coli into the Uterus with Cervix not Ligated

Abstract

An experimental production of pyometra was carried out with 49 mongrel bitches which belonged to various stages in the luteal phase.
These bitches were inoculated E. coli into the uterus with the cervix not ligated.
The incidence of so-called canine pyometra was seen in 93.9% as a total. These pyometra could be divided into two types by the histological findings: one showed the pattern with cystic endometrial hyperplasia (CEH) and the other not with CEH:
The type of pyometra with CEH could be seen in a relatively high ratio (80-100%) in the groups from day 1 (the first day of diestrus) to day 20, whereas the type without CEH could be seen in almost all cases in the groups from day 30 to day 40.
It was concluded that canine pyometra with CEH which usually was seen in the naturally occurring cases could be easily reproduced by the inoculation of E. coli into the uterus, unlike Dow's experiments, without administration of high doses and for a relatively long period of progesterone, and in the naturally occurring cases, bacterial infection must be one of the most important factors in the course of disease.