Anti-Müllerian hormone (AMH) is produced in animals at an embryonic level, being an important factor in sexual differentiation. It is also produced throughout an animal’s adult life, by the granulosa cells in mature ovaries, and Sertoli cells in the testicles.
Testing for this hormone has been important in human reproductive medicine, being used as an indicator of ovarian reserve, and used in IVF guidance, fertility planning and checking for menopause.
More recently, AMH testing has been used for evaluating the presence of active ovarian or testicular tissue in various species, including rabbits. Clinical signs associated with the possible presence of gonadal tissue in rabbits can include persistent sexual behaviours, nest making, mounting, spraying and aggression. However, these clinical signs can be seen in animals with other conditions, for example, adrenal gland disease, ovarian neoplasia, those that are in pain for various reasons, and individuals going through a benign, but feisty, period of spring fever!!
Testing for anti-Müllerian hormone involves taking just a single blood sample, much easier than previous tests, for example an HCG stimulation test, where two blood samples had to be taken a week apart. While ultrasonography can be a useful diagnostic tool, if only small remnants are present, they can be difficult to identify. Testing for AMH is a lot less invasive than exploratory surgery that can be expensive, traumatic and unnecessary.
A positive anti-Müllerian hormone test is indicative of the presence of either active ovarian or testicular tissue, which is helpful in the diagnosis of an ovarian remnant in females that have been spayed; cryptorchidism, albeit uncommon in this species; or if an animal has an unknown history.
This test is easy to interpret, with high levels (0.77-3.36 ng/ml) being indicative of ovarian or testicular tissue being present, and low or undetectable levels (≤0.01-0.23 ng/ml) being confirmation that the rabbit has been successfully neutered (Böhmer et al., 2022).
Reference
Böhmer, F., Erber, K., Ewringmann, A., Klein, R., Reese, S., Böhmer, C., Meyer-Lindenberg, A., & Walter, B. (2022). Anti-Müllerian hormone concentrations in female rabbits and its relation to spay status, pseudopregnancy and ovarian follicle numbers. Reproduction in domestic animals, 57, 1636-1643.