Morphological changes in bitches endometrium affected by cystic endometrial hyperplasia - pyometra complex - the value of histopathological examination.

Background: Cystic endometrial hyperplasia-pyometra complex (CEH-P) is one of the most common uteropathies in bitches. In diseases with mild or obscure clinical signs and normal uterine size, a diagnosis based on a clinical assessment might be incorrect. The main aim of the research was to determine the morphological variables accompanying uterine diseases in bitches in microscopic evaluation. Consequently, the obtained results can be used to create a new classification system for uterine pathological changes during the development of the CEH-P, diagnosed by microscopic examination in bitches. Material for the study consisted of the uteri of 120 female dogs, aged 1-16 years, obtained during routine ovariohysterectomies. Macroscopic observation after a longitudinal incision of the uterine horns, allowed a preliminary classification of the uteri into research groups: control group (physiological uteri), and groups GI-III uteri collected form bitches with varying degrees of endometrial pathology. These preliminary classifications were then verified by histological analysis (H&E stain).

Results: The obtained results made it possible to determine and describe the prevalence (%) of pathological changes characteristic of the analyzed uterine diseases in the examined bitches. Histopathological analyses that were conducted have confirmed preliminary macroscopic evaluation for the control group, group GII (CEH), and group GIII (pyometra). In the uteri of the GI group, a severe congestion of the endometrium has been observed - this is typical of inflammation - which was not confirmed during histopathological examinations. However, these examinations revealed acute endometrial haemorrhage of varying severity.

Conclusions: Early reproduction disorders in bitches are, in general, not confirmed by clinical signs in the examined animals. The results show that during classification of typical morphological changes in the endometrium over the development of the CEH-P complex in bitches microscopic examinations are required. The obtained results indicate a frequent lack of consistency in the macroscopic assessment and histological analysis of the endometrium, observed in the analyzed uterine diseases, which in most cases is not followed by clinical symptoms. The presented classification of uterine diseases may be useful as a diagnostic tool in reproductive disorders in bitches and in examination in the field of basic research.