Serum (clotted blood)
AMH is the test of choice for identifying cryptorchids of any age.
AMH is strongly expressed in Sertoli cells of the foetal, neonatal, and pre-pubertal testes, as well as cryptorchid testes, Sertoli cell tumours, and male intersex gonads. At puberty, maturation of Sertoli cells is accompanied by reduced production of AMH, however normally descended testes continue to produce some.
AMH is a reliable and specific test for the presence of testicular tissue in horses, ponies and donkeys at any age. AMH concentrations are significantly higher in cryptorchid stallions (mean 33 ng/mL) versus intact stallions (mean 15 ng/mL), and AMH is undetectable in geldings. Following castration, serum AMH concentrations decline rapidly (biological half-life of 1.5 days) making AMH a useful test if there is doubt over the success of a recent castration procedure.
It is also the preferred biomarker for granulosa cell tumours in mares.
See also:
- Granulosa cell tumours
- Cryptorchidism