Equis ISSN 2398-2977

Endocrine: hCG stimulation test

Contributor(s): Annalisa Barrelet, Graham Munroe, Janice Sojka, Han van der Kolk, David Rendle

Overview

  • Although basal testosterone Endocrine: testosterone assay in a cryptorchid horse Testis: cryptorchidism is usually above baseline levels of a gelding, it is not as reliable as a diagnostic test. The stimulation of testosterone production by a LH analogue is a reliable means of differentiating horses with and without testicular tissue.
  • hCG has an LH like effect stimulating the Leydig cells to produce testosterone.
  • If there is functional testicular tissue present there will be significant increase in plasma testosterone as a result of hCG administration (95% accurate).
  • The test is reliable when estrone sulfate Endocrine: estrone sulfate assay cannot be used, ie horses under 3 years of age and donkeys.
  • Anti-mullerian hormone is another means of detecting retained testicular tissue without the need for a stimulation test.

Sampling

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Tests

Methodologies

  • Samples need to be analyzed by laboratory with assays tuned for reading equine samples or false positive readings can be obtained.

Result Data

This article is available in full to registered subscribers

Sign up now to purchase a 30 day trial, or Login

Further Reading

Publications

Refereed papers

  • Recent references from PubMed and VetMedResource.
  • Cox J E, Redhead P H & Dawson F E (1986) Comparison of the measurement of plasma testosterone and plasma estrogens for the diagnosis of cryptorchidism in the horse. Equine Vet J 18 (3), 179-82 PubMed.
  • Stabenfeldt G H & Hughes J P (1980) Diagnostic endocrinology of the horse. Vet Clin North Am (Large Anim Pract) 2 (2), 253-265 PubMed.


ADDED