EN
The paper focuses on presenting structural and functional disturbances that can be diagnosed in changed ovaries in mares. Anamnesis, sexual behavior assessment, rectal palpation and ultrasonography enable the diagnosis of most of the pathological changes. Determining some of the ovarian disturbances demands biopsy, hormonal and cytogenetic analyses. The presence of small and inactive ovaries can indicate hypofunction or chromosomal hypoplasia. Enlarged ovaries can be accompanied by tumors, hematomas, cysts and abscesses. Some pathological changes influence the ovulatory cycle, others are insignificant for ovarian activity and fertility in mares.