Sonographic features of the uncomplicated postoperative abdomen in dogs treated for pyometra by ovariohysterectomy.

Pyometra is a prevalent disease in intact bitches and the standard treatment is ovariohysterectomy (OHE). Published descriptions of normal sonographic findings after OHE are currently lacking. The aims of this prospective observational study were to describe and compare postoperative abdominal sonographic features for three timepoints following OHE in a group of dogs with pyometra and an uneventful recovery. A total of 22 dogs had sequential focused abdominal ultrasound examinations on days 1, 4-6, and 10-15 postsurgery. Recorded sonographic features for each examination time point and characteristics of the cervical stump and the mesovarium, size, and echogenicity of medial iliac lymph nodes (MILNs), presence of free peritoneal fluid, and pneumoperitoneum. The cervical stump appeared as a heterogenous area with a hypoechoic center surrounded by hyperechogenic tissue in all dogs. The cervical stump transverse-sectional area was larger on day 4-6 compared with day 1 and day 10-15 (P = .0009). Mesovarium ligature reactions were identified as heterogeneous and hyperechoic areas with central and/or edge shadowing in all dogs. The size and echogenicity of MILNs and the mesovarium reactions did not significantly differ among time points. Free peritoneal fluid was detected in 45%, 41%, and 9% and pneumoperitoneum in 95%, 82%, and 14% of dogs at sequential time points. Findings from this sample of dogs with an uneventful recovery following OHE due to pyometra can be used to assist veterinarians in interpreting postoperative abdominal ultrasonographic characteristics in future dogs treated surgically for pyometra.