Canine Degenerative Myelopathy - Genetics

Genetics

Breeding risks for degenerative myelopathy can be calculated using the Punnett Square:

• If both parents are clear (N/N) then all of the puppies will be clear However, it is important to remember that 1 German Shepherd Dog out of hundreds tested had developed Degenerative Myelopathy, so perhaps this 1 dog's test needs to be revisited!
• If one parent is a carrier (N/A) and one is clear (N/N) then roughly 50% of the puppies will be clear and 50% will be carriers
• If both parents are carriers (N/A) then roughly 25% will be clear (N/N), 50% will be carriers (N/A), and 25% will be affected (A/A)
• If one parent is clear (N/N) and one parent is affected (A/A) then all puppies will be carriers (N/A)
• If one parent is a carrier (N/A) and one is affected (A/A) then roughly 50% of the puppies will be carriers (N/A) and 50% will be affected (A/A)
• If both parents are affected (A/A) then all puppies will be affected (A/A)