Mullerian Duct Syndrome (Miniature Schnauzer Type)

Test Overview:

Mullerian Duct Syndrome (MDS) is an inherited disorder of sexual development affecting male dogs. In early in-utero development all canine fetuses have precursors of the uterus, fallopian tubes and upper vagina called Mullerian ducts. In normal male fetuses, the Mullerian ducts regress as sexual differentiation occurs in-utero, allowing for development of male sexual anatomy. In affected male dogs the female reproductive organs fail to regress in-utero. Approximately half of the affected male dogs have externally normal testes and are fertile, but internally have remnants of female reproductive organs, including the uterus. The other 50% of affected male dogs have Cryptorchidism in addition to remnants of female reproductive structures. Cryptorchidism predisposes dogs to infertility and testicular tumors. Affected dogs may also have small testes. Female dogs may need to have a Hysterectomy if the uterus becomes infected. Females with this condition have normal internal and external female anatomy.


Reproductive - Associated with the reproductive tract


Anti-Mullerian hormone receptor type 2 (AMHR2) on Chromosome 27

Variant Detected:

Base Substitution c.262C>T p.R88STOP


Low-Moderate. This disease can cause some discomfort and/or dysfunction in the affected animal. It does not generally affect life expectancy.

Mode of Inheritance:

Autosomal Recessive

Research Citation(s):

Wu X, et al. A single base pair mutation encoding a premature stop codon in the MIS type II receptor is responsible for canine persistent Müllerian duct syndrome. (2009) J Androl 30(1);46-56.

Associated Breed(s):

Miniature Schnauzer, Mixed Breed, Schnoodle,