EN
The usefulness of three chemical methods (Couboni, Lunas and Rommel), rectal examinations and determination of electric conductivity of vaginal mucous in diagnosis of pregnancy in mares was evaluated. It was found that chemical methods based on the determination of oestrogens in urea between the 120 and 280 day of gestation agree in 100% with the existing pregnancy. Determining the electric conductivity of vaginal mucous by the use of an apparatus produced by Dramiiiski in useless for the diagnosis of pregnancy because of false positive results. Rectal examination from an early period of gestation (21-35 day) should be repeated after 90 days after mating.