title: Comparison of equine endometrial cytology samples collected with uterine swab, uterine brush, and low-volume lavage from healthy mares.
abstract: BACKGROUND
  There have been no studies evaluating and comparing the quality of equine endometrial cytology samples obtained via the 3 most common sampling techniques from healthy mares.
  
  
  OBJECTIVE
  The objective was to compare the quality and contents of equine endometrial samples obtained by 3 different sampling techniques: double-guarded uterine swab, double-guarded uterine brush, and low-volume lavage (LVL), all collected from clinically healthy mares.
  
  
  METHODS
  Samples were collected from 24 healthy mares in early estrus. In 19 mares, samples were obtained in a sequential manner, first with the swab, then with the brush, followed by LVL. Cytologic evaluation included estimates of quality, cellularity, and presence of inflammatory cells. The clinical pathologist performing the evaluations was blinded to the collection technique. The Friedman test with Dunn's multiple comparisons was used to compare rankings of quality, cellularity, and the presence or absence of inflammatory cells. Observed cytologic differences were described.
  
  
  RESULTS
  All techniques provided diagnostic samples, but swabs yielded the lowest quality sample. In our hands, the uterine brush provided the highest quality sample. Low-volume lavage samples contained higher numbers of neutrophils, although, in general, < 1 neutrophil/400× field is expected for all endometrial sampling techniques in healthy mares.
  
  
  CONCLUSIONS
  All sampling techniques can be adequate methods for endometrial cytology, but the brush technique consistently provided the best sample. Sample contamination or poor slide quality can adversely affect interpretation. The most accurate criteria for determining what constitutes mild endometritis in mares have yet to be established.
authors.affiliation: Department of Microbiology, Immunology, and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
authors.forename: Andrea A
authors.initials: AA
authors.lastname: Bohn
authors.forename: Ryan A
authors.initials: RA
authors.lastname: Ferris
authors.forename: Patrick M
authors.initials: PM
authors.lastname: McCue
mesh_terms: D000818:Animals; D003584:Cytological Techniques / Q000662:veterinary; D004717:Endometrium / Q000166:cytology*; D005260:Female; D006736:Horses / Q000033:anatomy & histology*; D010341:Pathology, Veterinary / Q000379:methods; D013048:Specimen Handling / Q000662:veterinary; D007507:Therapeutic Irrigation / Q000662:veterinary; D014599:Uterus / Q000166:cytology
keywords: Diagnostic quality; endometritis; microscopy; neutrophils; uterus