Persistent Mullerian Duct Syndrome, PMDS

Male puppies have a 50% chance of being cryptorchid (one or two undescended testicles), which is recognized in puppies. Cryptorchid dogs are more likely to develop testicular tumors and have poor fertility. PMDS dogs can also suffer from complications of their persistent uterus, including pyometra or hydrometra (pus or fluid-filled uterus) and endometritis (inflammation of the uterine lining); symptoms for these could range from abdominal swelling to abnormal behavior such as increased drinking to fever, vomiting, and collapse.

Dogs are born with this condition, but it is often not recognized until genetic testing or surgical sterilization is performed.

Genetic testing, clinical signs, and abdominal ultrasound can all be used in diagnosing this disease.

The treatment for both of these sequelae is surgical removal of the uterus and undescended testicles (orchidohysterectomy); however, genetic testing and prophylactic removal of the offending organs is probably the best way to treat this condition.

Talk to your vet about your dog’s PMDS result so you can plan appropriate monitoring and care.

Most dogs with PMDS don’t show any outward signs, and the condition is often discovered only if a complication develops. Discuss surgical sterilization with your vet, as this can help prevent issues such as infection of retained uterine tissue (pyometra) or testicular complications.

Schedule regular checkups so any changes such as abdominal swelling, abnormal discharge, or difficulty urinating can be identified and treated early.

This mutation was first described in Miniature and Standard Schnauzers.

Penetrance: This disease is inherited in an autosomal recessive manner, meaning that affected dogs must have two copies of the mutation to show clinical signs.

Gene

AMHR2

Inheritance type

recessive

Clinical category

Other Systems

Citations

1. Wu et al 2009
2. Liao et al 2009
3. Sapierzynski et al 2007

• Miniature Schnauzer
• Standard Schnauzer