Enzyme Immunoassay for the Measurement of Estrone Sulfate in Cryptorchids, Stallions, and Donkeys

The measurement of estrone sulfate, performed by an enzyme-linked immunosorbent assay, is a useful and reliable diagnostic alternative test for the detection of cryptorchidism in the horse and donkey. Mean values are provided in this report for 48 known cryptorchid horses, 49 geldings, and six stallions ranging from 1 to 10 years of age. These values show significant differences between geldings and cryptorchids ( p 5 0.0005), cryptorchids and stallions ( p 5 0.01), geldings and stallions ( p 5 0.003) and between horses ,2 years of age ( p 5 0.0003). Authors’ addresses: Dept. of Population Health and Reproduction, School of Veterinary Medicine, University of California at Davis, Davis, CA 95616 (Carneiro, Liu, and Munro) and Depto. de Fisiologia Animal, Facultad de Veterinaria UCM, 28040 Madrid, Spain (Illera). r 1998 AAEP.