Diagnosis and Treatment of Vesicovaginal Reflux in the Mare

Creatinine concentrations of accumulated intrauterine fluid to confirm the clinical diagnosis of urometra in mares

“…Although it was unknown whether creatinine concentration of fluid collected from the cranial vagina could be used to diagnose urine pooling in mares definitively, its effectiveness in confirming the clinical diagnosis of urometra has been speculated but not critically assessed (Easley 1988). Here for the first time, the authors documented that collection of uterine fluid and determination of creatinine concentration can be used to confirm the clinical diagnosis of urometra in mares.…”

“…A creatinine concentration in the fluid that has accumulated in the vaginal fornix of mares above 2–3 times the blood creatinine concentration is suggestive of urovagina (Easley 1988). Whereas a concentration greater than 2.0 mg/dl is considered diagnostic for urospermia (Hurtgen 1987, Althouse and others 1989, Ellerbrock and others 2016).…”

“…It commonly occurs in older mares due to conformational abnormalities of the caudal reproductive tract, in which the cranial vagina slopes cranioventrally, or in the postpartum period as the reproductive tract has been traumatised and is still involuting (McKinnon and Belden 1988, Woodie 2012). During oestrus, urine may flow through the open cervix, resulting in urometra, which can have a substantial negative impact on fertility (Brown and others 1978, Easley 1988, McKinnon and Belden 1988, Woodie 2012). …”

“…The presence of urine in the uterine lumen and cranial vagina can cause cervicitis, endometritis and also directly interfere with sperm viability (Griggers and others 2001, Ellerbrock and others 2016). Most mares that present with transient urometra/urovagina up to 20–30 days post partum will often self-resolve after that, but those who continue to experience urometra are likely to require a urethral extension surgery and extensive management to address the chronic endometritis caused by this condition (Easley 1988). …”

“…To the authors’ knowledge, there is currently no reported proven method to confirm the clinical diagnosis of urometra. Since creatinine is present in high concentrations in urine and does not diffuse across cell membranes, creatinine concentration should be increased in mares with urometra, but negligible in normal and those mares with intrauterine fluid accumulation without urine contamination (non-urometra cases), In cases of urometra, intrauterine creatinine concentrations should be increased at least twofold to threefold compared to blood creatinine concentrations (Easley 1988). Also, creatinine concentration has been used successfully in the diagnosis of urospermia in stallions using this same logic (Althouse and others 1989).…”