'Congenital' means 'present at birth'. By itself, it does not imply whether or to what degree a trait is due to genetic predisposition or environmental factors. Researchers agree that both contribute to the development of HD.
Quick summary of the argument Carol Beuchat made based on the available literature:
HD is not congenital, i.e. pups are born with well fitting hip joints. HD develops due to laxity of the joints, a ligament issue:
"The teres ligament should hold the head of the femur securely in the socket of the growing puppy while the muscles that will support the hip develop and grow stronger. But in some puppies, the ligament shows evidence of damage before they are even a month old (Riser 1985). The abnormal forces on the femur and acetabulum that are caused by joint laxity result in the trauma that causes hip dysplasia and osteoarthritis of the hip."
Among the environmental factors identified to contribute to joint laxity:
- Slippery surface of the whelping box (e.g. kiddie wading pools without added carpet) due to the movements it forces the pups to make
- Body weight
A multifactorial genetic component is undisputed among researchers. Using the ZW in mate selection is crucial.
Chip v. Dog Pound (border terrier), CGC
Elly v. Rescue (GSD, GSRNE 346), HI(C), CGC, TT
RIP: Feli, Iris, Dago (GSDs), Bubi (spitz), Tanja and Robin (mutts)