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.

Is uterine blood flow influenced by hCG and mare age?

Doppler ultrasonography is a noninvasive technique which enables us to follow the physiologic and physiopathologic changes in blood flow in tissues. It is becoming an essential tool in veterinary medicine, especially in theriogenology. Twenty-seven Arabian mares were grouped by age ('young', 3-10 y, n=15; 'old', 19-23 y, n=12). The uterine arteries of the mares were examined using Doppler ultrasonography when an ovarian follicle ≥35mm was visible (Day -1). After these measurements, human chorionic gonadotropin (hCG; 2500IU) was administered to 14 mares selected randomly. One day later (Day 0) Doppler ultrasonography was repeated and then the dominant follicles were aspirated to collect follicular fluid in all groups. On the next day (Day +1), Doppler indices of the uterine artery blood flow were measured again. Blood samples were also collected just prior to ultrasonography, for measuring serum estradiol and progesterone levels. We found that preovulatory hCG administration had no significant effects on uterine artery blood flow indices, or serum or follicular fluid estradiol concentrations. The uterine artery resistance index might decrease in young mares after ovulation, possibly because of increased uterine perfusion.