GM1 Gangliosidosis (Discovered in the Portuguese Water Dog)

Gangliosidosis is characterized by progressive neuromuscular dystrophy and proportional dwarfism. Clinical signs are typically first observable in two month olds and become obvious by 7 month. They include vision impairment, head tremor, involuntary eye movements, limb weakness with difficulties in walking/balancing and fatigue with loss of appetite.

Upon initial observation of clinical signs, affected dogs should be closely monitored to assess welfare, and devise a supportive care treatment plan. As clinically signs are progressive, affected dogs are usually euthanized on welfare grounds by 1 year of age.

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 develop. A carrier dog with one copy of the GM1 Gangliosidosis mutation can be safely bred with a clear dog with no copies of the GM1 Gangliosidosis mutation. About half of the puppies will have one copy (carriers) and half will have no copies of the GM1 Gangliosidosis 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 GM1 Gangliosidosis mutation could develop due to a different genetic or clinical cause.