Equitest ES utilizes an immunochromatographic procedure to measure serum/plasma concentrations of pregnancy specific steroids secreted by the fetal-placental unit in all breeds of horses. The test requires a volume of 0.1 to 0.2 ml of serum or plasma taken 120 days after mating through to expected foaling. The serum/plasma sample is dropped into the well of a plastic cassette which holds the test membrane. This starts a color change chemical reaction which is completed within 5 to 10 minutes. Serum/plasma from a non-pregnant mare produces a visible red line and red dot on the test membrane, while only a single line is generated by serum/plasma from a pregnant mare.
Equitest ES can be used to pregnancy test all breeds of horses. It can also be used on donkeys. The test is particularly useful for pregnancy testing miniature mares where pregnancy diagnosis by rectal palpation or internal ultrasound scanning is not recommended because of their small size.