A contrast radiographic study of the vagina and uterus of the normal bitch

A method is described for investigating radiographically the shape of the bitch's vagina. The intra‐pelvic vagina is readily dilated whereas the intra‐abdominal vagina is narrow and tortuous, and cranially is typically ‘spoon‐shaped’. Contrast medium entered the uterus during pro‐oestrus, oestrus and the post‐partum period, indicating patency of the cervix at these times. No cervical relaxation was evident at the end of the luteal phase, i.e. during anoestrus. The possible relevance of these findings to the aetiology of pyometra is discussed.