Prevalence of subclinical uterine pathologies diagnosed by biopsy and cytological and bacteriological findings in cyclic bitches.

The study was performed on 45 bitches in different cycle phases that were divided into the following groups: anoestrus (I, n=15), heat (pro-oestrus (n=7) or estrous (n=8) (II, n=15) and metestrus (III, n=15). Moreover, all experimental dogs were grouped according to their age: younger than 5 years (Y, n=35) and older than 5 years (O, n=10). The endometrial status was evaluated using cytological, bacteriological and biopsy samples obtained after ovariohysterectomy. The main uterine pathology diagnosed by biopsy was endometritis, since 40%-66% of bitches, independent of the experimental group, developed this condition. No significant differences were found among the cycle phase groups (p>0.05). By contrast, significant differences were found in the age groups; the prevalence of this pathology was higher in older bitches (p=0.0019). The general prevalence of cystic endometrial hyperplasia (CEH) and a normal endometrium (NE) was lower (6.7-26.7% vs 26.7-53.3%) in all groups, and no statistically significant differences were found between certain groups (p>0.05). The percentage of polymorphonuclear neutrophilic leukocytes (PMNs) in endometrial cytology was generally low (⟨ 2%) and did not differ significantly among the experimental groups (p=0.142). In general, a low degree of correlation was found between the diagnostic results by endometrial cytology and biopsy (Kappa Coefficient= 0.046). Positive bacteriological findings were found in approximately 50% of the bitches, independent of the cycle phase and health status of the endometrium. No correlation was found between the bacteriological and histopathological findings (p=0.883). In conclusion, uterine cytology is not a reliable diagnostic method to detect the subclinical inflammatory and degenerative uterine pathologies in cyclic bitches.