Leukocyte Esterase Reagent Strips for Stall-Side Diagnosis of Endometritis in Mares.
Authors: Kelley Dale E, Schnobrich Maria R, Gayer Stephany, Scoggin Charles, Bradcamp Etta, Canisso Igor F
Journal: Journal of equine veterinary science
Summary
# Editorial Summary Endometritis remains a significant cause of subfertility in mares, yet reliable stall-side diagnostic methods remain limited. Dale and colleagues evaluated whether commercially available leukocyte esterase reagent strips—commonly used for urinary screening—could accurately identify endometritis when applied to endometrial cytology samples, comparing results against standard cytological examination in 46 light breed mares during the breeding season. Using Kalayjian swabs to obtain endometrial samples, the researchers established that the leukocyte esterase test demonstrated moderate correlation with cytology (r = 0.698) and achieved a receiver operator curve area of 0.871, with a cutoff point of trace or greater positivity yielding 77.8% sensitivity and 94.6% specificity. Whilst the test's high specificity (94.6%) makes it valuable for confirming endometritis when positive—particularly in clinically severe cases—its relatively modest sensitivity (77.8%) means negative results cannot reliably exclude subclinical or mild inflammatory disease. For practitioners, this suggests the leukocyte esterase strip may serve as a useful rule-in tool when resources for full cytological evaluation are unavailable, though negative results should prompt further investigation through conventional cytology or culture before assuming reproductive clearance, particularly in mares with history of subfertility.
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Practical Takeaways
- •Leukocyte esterase strips can be used as a quick stall-side screening tool to confirm suspected endometritis (high specificity), but negative results cannot exclude the disease and require follow-up cytology or culture
- •Use a cutoff point of trace or greater on the strip to optimize sensitivity-specificity balance for clinical decision-making
- •Combine LET with endometrial cytology rather than relying on culture results for more reliable endometritis diagnosis during breeding management
Key Findings
- •Leukocyte esterase test showed moderate correlation with endometrial cytology (r = 0.698) but poor correlation with culture results
- •LET achieved 77.8% sensitivity and 94.6% specificity for endometritis diagnosis using trace or greater as cutoff point
- •LET receiver operator curve area under curve was 0.871, indicating good discriminatory ability
- •LET can rule in endometritis in severe cases but is insufficiently sensitive to rule out the condition