Comparison of equine endometrial cytology samples collected with uterine swab, uterine brush, and low-volume lavage from healthy mares.

The research article compares the effectiveness of three common methods for obtaining equine endometrial cytology samples from healthy mares. The study found that all techniques provided diagnostic samples but the brush technique consistently yielded the highest quality.

Objective

The primary goal was to assess the quality and content of endometrial samples collected by three different techniques:

• Double-guarded uterine swab
• Double-guarded uterine brush
• Low-volume lavage (LVL).

All these methods were applied to clinically healthy mares.

Methodology

Using a cohort of 24 healthy mares in early estrus, sample collections were performed. In 19 mares, the samples were collected sequentially starting with the swab, followed by the brush, and finally the LVL. Evaluation of cytology included estimates of quality, cellularity, and the presence of inflammatory cells. The pathologist conducting these evaluations was unaware of the collection method employed. The Friedman test with Dunn’s multiple comparisons was applied to compare rankings of quality, cellularity, and inflammatory cell presence or absence.

Results

It was observed that while all techniques provided diagnostic samples, swabs seemed to yield the lowest quality. The highest quality sample was produced using the uterine brush. The LVL samples consisted of a higher number of neutrophils, but healthy mares generally exhibited less than one neutrophil per 400x field across all sampling techniques.

Conclusion

The study concluded that all three sampling techniques are adequate for endometrial cytology with the brush method consistently providing the best quality. Poor slide quality or sample contamination could compromise the interpretation. Moreover, the study noted that concrete criteria defining mild endometritis in mares have yet to be established.