[Estrus detection in the bitch with a progesterone rapid test (EIA)--a sensible supplement to vaginal cytology].

Vaginal smears were taken from 42 bitches and the results were compared with serum levels of progesterone, which were measured by a radioimmunoassay as well as by a qualitative enzyme-immunoassay. With the enzyme-immunoassay it was possible to differentiate low progesterone levels (less than 3.9 ng/ml) and high progesterone levels (greater than 4.2 ng/ml). Timing of insemination or mating of the bitches using both methods showed good pregnancy rates.