Updated breeding guidelines for syringomyelia
One goal of the neurologists when they met in London in November for the SM conference was to produce an agreed set of breeding recommendations. They agreed to use Clare Rusbridge's guidelines as a basis and agreed -- actually on Clare Rusbridge's instigation -- to do away with the A* grade and also the B grade for dogs. Elsewhere I have posted the reasons for this and I'll add the link when I get the chance.
These are the new recommended breeding guidelines and grading schemes for cavalier breeders:
Grade A /Over 2.5 years old /SM absent or less than 2mm central canal dilatation in the C2-C4 region only /Breed to A, C, D dogs
Grade C /Under 2.5 years old /SM absent /Breed only to A dogs and rescan after 2.5 years of age
Grade D /Over 2.5 years old /Syrinx present but dog asymptomatic /Breed only to A dogs
Grade E /Under 2.5 years old /Syrinx present but dog asymptomatic /Do Not Breed
Grade F /Any Age /Syrinx present and dog symptomatic /Do Not Breed
Recommended that both the sire and the dam of a proposed mating are screened (any unscreened dog should be assumed to be "D")
These breeding recommendations are made using current information and in response to CKCS breeder request for guidelines. It has yet to be proven if this guide is appropriate. The aim of these recommendations is to reduce the incidence of symptomatic SM in the breed, NOT to create litters of puppies guaranteed not to have SM as the chance of producing an affected dog cannot be predicted without knowing the inheritance.