The males affected with PMDS appear externally normal, but they have a uterus, cervix, part of the vagina, and fallopian tubes. Approximately 50% of PMDS-affected males are cryptorchid (absence of one or both testes from the scrotum). PMDS is characterized by sterility or subfertility, but affected males that are unilateral cryptorchids have sired litters. Aged PMDS dogs may develop pyometra (uterine infection) or a Sertoli cell tumor.

Treatment is surgical removal of any female reproductive organs and retained testes to eliminate the risk of uterine infections or Sertoli cell tumors. It is also recommended that any descended testes be removed to prevent unintended matings that could allow the mutation to be passed on to puppies.

There are many responsibilities to consider when breeding dogs. Regardless of test results it is important that your dog is in good general health and that you are in a position to care for the puppies if new responsible owners are not found. For first time or novice breeders, advice can be found at most kennel club websites.

This disease is autosomal recessive meaning that two copies of the mutation are needed for disease signs to occur. A carrier dog with one copy of the PMDS mutation can be safely bred with a clear dog with no copies of the PMDS mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the PMDS mutation. Puppies in a litter which is expected to contain carriers should be tested prior to breeding. Carrier to carrier matings are not advised as the resulting litter may contain affected puppies. Please note: It is possible that disease signs similar to the ones caused by the PMDS mutation could develop due to a different genetic or clinical cause.