Influence of vulvar hygiene on cytology of vaginal smears after sham artificial insemination in sows.

The description of vaginal cytology in the sow in relation to artificial insemination (AI) has never been reported. Poor vulvar hygiene is frequently imputed as a cause for the development of endometritis after AI and could thus enhance the inflammatory response of the genital tract. The goal of this study was to use cytology as an objective tool to evaluate the vulvar hygiene during sham AI. Sixty-eight sows were matched according to their parity and week of mating and divided into 2 groups: treatment sows (CVS) had their vulva cleaned with a 1:2000 Hibitane solution and control sows (SVS) had theirs soiled with feces. Both groups of sows were inseminated twice with saline following this vulvar treatment, once at detection of estrus and a 2nd time 24 hours later. Vestibular smears were taken before each AI, and vaginal smears were taken after each AI from the material present on the insemination spirette. Cytological smears were described by the predominant type of cells, namely epithelial, neutrophil, or no predominance. Results showed no significant differences between the 2 groups and no evolution in the predominance of neutrophils from the 1st to the 2nd AI (P > 0.05). The pooled results from the 2 groups showed an increase in cellularity from the 1st to the 2nd AI (P > 0.05). Neither the cellularity nor predominant cell type in vestibular or vaginal smears from estrus sows are predictors of vulvar hygiene during sham AI (P > 0.05).