Comparison of vaginal cytology and histopathologicalexamination of the uterus in cats

This thesis study aimed to investigate the relationship between vaginal cytology samples taken at different periods of the sexual cycle in cats and histopathological findings of the uterus. Fifty-six healthy female cats scheduled for ovariohysterectomy were used in the study. Vaginal smear samples were obtained from all cats and grouped according to sexual cycle periods. Tissue samples were taken from the uterus during ovariohysterectomy for histological examination. Ten cats were in prooestrus, 14 cats in oestrus, 12 cats in interoestrus, 10 cats in dioestrus, and 10 cats in anoestrus. The cornified cell (CC) ratio was determined at the highest level in the oestrus and was found to be statistically significantly higher than all other periods (p<0.05). The CC ratio was found to be higher in proestrus and interoestrus compared to diestrus and anoestrus and higher in the dioestrus compared to anoestrus (p<0.05). There was no significant difference between prooestrus and interoestrus periods in terms of CC ratio. Sections taken from uterine tissue were stained with hematoxylin-eosin, tissue preparations were prepared, and cornu uteri diameters (CUD), endometrial thickness (ET), myometrial thickness (MT), and glandular diameters (GD) were measured, and cystic dilatation status of endometrial glands was recorded. The means of CUD, MT, and ET did not show a statistically significant difference between different periods of the sexual cycle. The mean GD was similar in dioestrus and prooestrus and was found to be higher in these periods compared to interoestrus and oestrus (p<0.01). Prooestrus, oestrus, and interoestrus were considered as follicular period, while dioestrus and anoestrus were considered as luteal period. No significant differences were found in the mean values of CUD, ET, MT, and GD between these periods. A moderate positive correlation between CC ratio and only MT values among histopathological parameters (p<0.05). There was no significant correlation between other histopathological data and CC ratio. There was no significant correlation between the severity of cystic endometrial hyperplasia and the CC ratio. It was concluded that although vaginal cytology is an effective method in determining the sexual cycle period, it does not fully reflect the physiological and pathological status of uterine tissue.