Minimal external masculinization in a SRY-negative XX male Podenco dog

[Diagnostic utility of the anti-Mullerian hormone in companion animals]

The anti-Mullerian hormone is a glycoprotein secreted by Sertoli cells in males and granulosa cells in females. The initial identification of this hormone in canine and feline serum was achieved in 2011. Meanwhile, a variety of studies have demonstrated its clinical significance as a tool in the endocrine diagnosis. This review summarizes the current knowledge about anti-Mullerian hormone in small animal reproduction and describes future opportunities for its diagnostic usage.

Serum anti-Müllerian hormone concentration as a diagnostic tool to identify testicular tissue in canine disorders of sexual development

Disorders of sexual development (DSD) may have their origin in alterations of the chromosomal, gonadal or phenotypic sex. Affected animals are usually presented because of ambiguous external genitalia, seldom because of reproductive disorders. Anti-Müllerian hormone (AMH) is secreted in the gonads with higher amounts in males than in females and can be used to identify gonadal tissue in sexually normally developed dogs. The aim of this study was to examine the diagnostic potential of serum AMH to identify testicular tissue in 11 dogs with DSD. The diagnostic procedures applied were: determination of the phenotypic sex (n = 11), genital ultrasound (n = 9), determination of the SRY gene (n = 11), karyogram (n = 6), gonadectomy (n = 11), pathohistology of the gonads (n = 10), serum AMH measurement (n = 11). 39 female dogs described in a previous study and 19 male dogs with a normal spermiogram served as controls for the AMH serum concentrations in sexually intact dogs. The 11 dogs with DSD were classified as 7 XY DSD and 4 XX DSD. Presumptive testes were obtained in 10 dogs and 1 dog had an ovotestis combined with a testis. Mean serum AMH values of the dogs with DSD were significantly higher (P < 0.001) than in male and female controls. The upper limit of the AMH test (≥ 23ng/ml) was reached in 6 dogs. High AMH concentrations have been described previously in cryptorchid dogs. 1 dog with a male phenotype and 2 with a female phenotype had AMH values within the range of the male controls, although all of them had cryptorchid testes. A Poodle, in which epididymis were identified but no definitive gonads, had an AMH concentration of the lower limit of the test (≤ 0.01 ng/ml), comparable to previously described castrated dogs. This study indicates that serum AMH levels are a useful diagnostic tool to identify testicular tissue in dogs with DSD and suggests the possible use of AMH to diagnose testicular dysgenesis.

Laparoscopic gonadectomy in dogs with ovotesticular disorder of sexual development

Disorders of sexual development (DSD) in dogs involve most commonly an XX sex reversal syndrome, treated conventionally by gonadohysterectomy. The objective of the present case series is to describe the surgical treatment and long-term follow-up of dogs undergoing laparoscopic gonadectomy without hysterectomy for treatment of ovotesticular DSD. Six female dogs clinically diagnosed with DSD were retrospectively included in the study when laparoscopic gonadectomy was performed and histology confirmed the presence of abnormal gonads. The dogs were evaluated by ultrasound after 6 months, and owners were contacted by phone for the long-term reevaluation. Laparoscopic gonadectomy was performed using 2- or 3-portal midline techniques with 3- and/or 5-mm instruments. Additional procedures were performed in 5 dogs, including os clitoris removal in 4 dogs and vulvoplasty in 1 dog. Histological analysis of the gonads reported 11 ovotestes and 1 testis. No major or minor complications occurred perioperatively. Ultrasonographic reevaluation was performed in 5/6 dogs and the remaining abdominal genital system was considered normal. Median long-term follow-up was 617 days (range, 265-1597) with none of the dogs having any symptom related to DSD. Therefore, laparoscopic gonadectomy is a valid alternative for dogs with ovotesticular DSD and is less invasive than conventional open techniques. Removal of the gonads avoids future development of hormone-related diseases of the remaining genital tract.

Gonadal and sex differentiation abnormalities of dogs and cats

The molecular steps in normal sexual development were largely discovered by studying patients and animal models with disorders of sexual development (DSD). Although several types of DSD have been reported in the cat and dog, which are often strikingly similar to human DSD, these have been infrequently utilized to contribute to our knowledge of mammalian sexual development. Canine and feline cases of DSD with sufficient evidence to be considered as potential models are summarized in this report. The consensus DSD terminology, and reference to previous terminology, is used to foster adoption of a common nomenclature that will facilitate communication and collaboration between veterinarians, physicians, and researchers. To efficiently utilize these unique resources as molecular tools continue to improve, it will be helpful to deposit samples from valuable cases into repositories where they are available to contribute to our understanding of sexual development, and thus improve human and animal health.