Concentrations of anti-Müllerian hormone in the domestic cat. Relation with spay or neuter status and serum estradiol.

Female cats with unknown history can be diagnosed as spayed or intact with a GnRH-stimulation test or an LH test independent of the stage in the estrous cycle. However, although most females are correctly diagnosed with the LH test, the sensitivity and specificity are not 100%. The GnRH-stimulation test, although reliable, requires an injection of buserelin 2 hours before the blood sample is collected. Granulosa cells are the only cell type that produces anti-Müllerian hormone (AMH) in females, whereas Sertoli cells produce AMH in males. Anti-Müllerian hormone has been linked to spay status in dogs and cats and to ovarian and testicular pathology and fertility in different species. Our aim was to evaluate serum AMH concentrations in spayed female cats and in intact female cats of known age and reproductive stage (inactive ovaries or luteal phase). In addition, our aim was to compare serum AMH concentrations in intact and neutered male cats. We analyzed serum AMH concentrations in 15 spayed and 16 intact females and in 15 intact and 12 neutered male cats. Serum AMH was below the lowest standard point (<0.14 ng/mL) in all spayed females and neutered males, ranged between 1.3 and 19.0 ng/mL in the intact females and between 4.8 and 81.3 ng/mL in intact males. Thus, the AMH test had 100% sensitivity and specificity to diagnose the presence or absence of ovaries and testes in this study. In addition, in contrast to serum estradiol, serum AMH was not affected by buserelin stimulation (P = 0.459). Serum AMH was not correlated with serum estradiol before (rs = -0.188, P = 0.519) or after (rs = 0.335, P = 0.242) buserelin stimulation in the intact females. Four 6-month-old intact cats (two females and two males) had the highest AMH concentrations which in the females might represent a prepubertal peak previously described in other species and in males is likely due to high concentrations before puberty. In conclusion, we found that the AMH Gen II ELISA is reliable for diagnosing spay and neuter status of cats and that the domestic cat might be an interesting model for studies on AMH dynamics.