Some of farmers' best friends, working dogs, are suffering an increasing incidence of hip dysplasia, a connective-tissue disease common in dogs that may be affecting up to a quarter of huntaways.
Farmers need to recognise how serious the crisis is, according to a spokesman for the soundness committee of theSheep Dog Trial Association, Tony Shield.
Hip dysplasia is the abnormal development of the hip joint - the ball joint of the femur fits too loosely into the hip joint. This causes abnormal wear and leads to degenerative arthritis in dogs.
Mr Shield, a dog trialist and huntaway breeder from Blenheim, said he hoped owners of winning dogs this season would be aware of the hip dysplasia status of all dogs used for breeding.
It was irresponsible for breeders of winning dogs to continue breeding from an animal they suspected would pass on the genetic fault.
Surveys by Taihape vet Paul Hughes had shown about 25 per cent of New Zealand huntaways had hip dysplasia, but only 5 per cent of heading dogs showed the defect.
The condition has spread by breeding successive generations to popular dogs that won trials but must have carried the hip dysplasia gene.
The disease drastically shortens the life of a working dog, despite the expense and time of rearing and training it. It is also very painful.
Mr Shield said geneticists had shown the defect was highly heritable and made worse by breeders meeting the demand for big dogs, which were then fed high-protein diets as pups to encourage rapid growth.
"We must recognise there is a crisis and it's vital breeders of huntaways get their stud dogs properly checked using x-rays by a vet," he said.
Buyers should demand a veterinary certificate from breeders to show the animal is free from hip dysplasia, Mr Shield said.
