Investigation of diagnostic use of serum anti-Müllerian hormone concentration in dioestrus and anoestrus bitches before and after ovariohysterectomy and the relationship with ovarian follicle numbers

Half-life of serum anti-Müllerian hormone and changes after gonadectomy in adult female and male dogs with normal and abnormal gonads

Anti-Müllerian hormone (AMH) is a biomarker for the presence of gonadal tissue. Changes in serum AMH after gonadectomy are not well established, and its serum half-life is unknown in dogs. We measured serum AMH with a validated electro-chemiluminescent immunoassay in adult female (n = 12) and male (n = 7) dogs with normal gonads, as well as in dogs with gonadal pathology (ovarian remnant syndrome, ORS n = 3, testicular tumor [Leydig cell, Sertoli cell, seminoma] n = 3, unilateral abdominal cryptorchid n = 4) on the day of gonadectomy (D0), and on D3, D7, D14 (females and males), and D21, D28 (males only). Males had higher AMH concentrations than females independent of gonadal status (P < 0.001). Dogs with ORS had lower initial AMH (0.45 ± 0.43 ng/ml) than bitches with normal gonads (1.16 ± 0.44 ng/ml; P = 0.027). Cryptorchid dogs had higher initial concentrations (80.57 ± 52.81 ng/ml) than males with normal gonads (7.92 ± 2.45 ng/ml; P = 0.004), and those with testicular tumors (18.63 ± 5.04 ng/ml) were intermediate (P ≥ 0.250). AMH decreased over time (P ≤ 0.012) and was 0.01-0.04 ng/ml by D14 in females and 0.02-0.12 ng/ml by D28 in males. Serum half-life in the whole study population was 2.85 ± 0.51 days and did not differ between groups. In conclusion, serum AMH can differentiate between intact and gonadectomized status of adult dogs by 14 days after ovario(hyster)ectomy in females and by 28 days after surgical castration in males.

Anti-Müllerian hormone concentrations in female rabbits and its relation to spay status, pseudopregnancy and ovarian follicle numbers

Anti-Müllerian hormone (AMH), known for its role during fetal sexual differentiation, is secreted by the Sertoli cells in males and the granulosa cells in females during postnatal life. As serum AMH concentrations correlate with follicle numbers, AMH is utilised as a marker of ovarian reserve in many species. In dogs and cats, AMH is used as a diagnostic tool to determine spay or neuter status. In the available literature, no research regarding serum AMH levels in rabbits has been published yet. The objectives of the present study were to 1) measure serum AMH concentrations in female rabbits and investigate the value of AMH as a diagnostic tool to differentiate between spayed and intact does, and 2) relate measured AMH levels to pseudopregnancy and ovarian follicle numbers. For AMH measurement, serum samples were obtained from sexually intact (n = 64) and spayed (n = 22) female rabbits. Spayed does were of various breeds; intact rabbits were Zika hybrid rabbits. In the intact does, AMH measurement was complemented by determination of progesterone levels, gynaecological examination, and histopathologic evaluation of the uterus and ovaries, including follicle counts. Serum AMH and progesterone concentrations were measured using a human-based chemiluminescence immunoassay (CLIA) and an enzyme-linked fluorescence assay (ELFA), respectively. Depending on progesterone levels, sexually intact does were classified into follicular (n = 52) or luteal phase (n = 12). Median serum AMH levels were 1.53 ng/ml (range 0.77 - 3.36 ng/ml) in intact and 0.06 ng/ml (range ≤ 0.01 - 0.23 ng/ml) in spayed does. AMH concentrations between the intact and spayed rabbits differed significantly and did not overlap (p < 0.001). Receiver operating characteristic (ROC) curve analysis yielded a sensitivity and specificity of 100% for a cut-off level of 0.50 ng/ml. Follicular or luteal phase had no significant influence on measured AMH levels (t = 0.061, df = 62, p = 0.951). While the number of secondary follicles correlated significantly with AMH concentrations (r_s = 0.410, p = 0.001), the number of primary or antral follicles did not (r_s = 0.241, p = 0.055 and r_s = 0.137, p = 0.281, respectively). In conclusion, a single determination of serum AMH concentrations was adequate to distinguish spayed from intact female rabbits. Among sexually intact individuals, whether does were in follicular or luteal phase had no significant influence on measured serum AMH concentrations. The relationship between small growing follicles and AMH levels as described in other species could be partially confirmed, as secondary follicles correlated significantly with AMH.