Doppler ultrasound assessment of uterine artery in canine endometritis

This study aimed to describe and compare uterine artery velocimetry in bitches suffering from endometritis, cystic endometrial hyperplasia (CEH) and healthy animals, and to evaluate the effect of clinical, ultrasonographic, bacteriological and histopathological parameters on the uterine artery resistance index in these bitches. According to clinical, two-dimensional ultrasonographic, gross and histopathological uterine evaluation, thirty-three bitches were classified as: Endometritis (END; n = 13), CEH (n = 7) and healthy bitches (NG; n = 13). Uterine ultrasonographic examinations were performed on each patient using B mode and pulsed-wave Doppler. Peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI) were obtained. A generalized linear model was carried out to analyze the effect of group, clinical, ultrasonographic, bacteriological and histopathological variables on PSV, EDV and RI. EDV was higher in CEH than END (P < 0.05) and NG (P < 0.01). No difference was observed between END and NG (P > 0.1). END presented a lower RI than NG and higher RI than CEH (P < 0.01). Additionally, CEH showed lower RI than NG (P < 0.01). This study showed an effect of higher values of endometrium thickness, PMNN/HPF and vascular congestion on RI (P < 0.01). It was concluded that, in these bitches, uterine artery RI was a valuable parameter to distinguish endometritis from normal uterus and CEH. An increase in neutrophils and vascular congestion influenced RI, remarking the importance of angiogenesis and the inflammatory reaction on uterine perfusion increase. This study is the first to identify an ultrasound parameter that differentiates endometritis from normal uterus in dogs.