Anti-Müllerian hormone as a diagnostic tool for ovarian remnant syndrome in bitches

Ovariohysterectomy is a surgical procedure performed for sterilization. If part or all of an ovary remains after the surgical procedure, ovarian remnant syndrome (ORS) occurs. After revascularization of the remaining ovarian tissue, the sexual cycle of bitches and queens continues. The aim of this study was to investigate the usefulness of serum anti-Müllerian hormone (AMH) measurement for the diagnosis of ORS in bitches. Forty-six female dogs were divided into four groups: the prepubertal, unspayed, spayed, and ORS groups. The serum AMH, progesterone, and estradiol concentrations of the bitches in all groups were measured by enzyme-linked immunosorbent assay. The stage in the sexual cycle of each bitch was determined based on vaginal cytology findings and serum estradiol and progesterone levels. The mean serum AMH concentration of the unspayed bitches (4.26 ± 0.82 ng/ml) was similar to that of the bitches with ORS (4.40 ± 1.09 ng/ml). However, the difference between the mean serum AMH level of the bitches with ORS and the spayed bitches (0.28 ± 0.09 ng/ml) was significant. In conclusion, the present study has demonstrated that the serum AMH level is substantially lower in spayed than in both intact bitches and bitches with ORS. According to this result, measurement of the serum AMH level is a useful tool for diagnosis of ORS in bitches.