Breeders may be able to do even more about preventing dysplasia in their litters than previously known.
While genes set up the possibility of hip dysplasia, studies have pointed to weight and rapid growth as triggers for its development. Now, new research indicates that the environment during a puppy’s first three months of life may have more effect on its risk for developing the condition.
Randi I. Krontveit, D.V.M., Ph.D., spent 10 years doing canine dysplasia research for her doctoral thesis. “I had been working as a clinician for quite a few years when this study was started at the Norwegian School of Veterinary Science, and I applied for this Ph.D. position. It was a great opportunity for me to do research.”
To find dogs for the study, the project leaders, her colleagues at the vet school and the Norwegian Kennel Club “all played an important role in recruitment of dog breeders,” Krontveit explains. “These breeders again recruited dog owners by getting their puppy buyers interested and committed to this project.”
She studied five hundred privately owned Newfoundland, Labrador Retriever, Leonberger and Irish Wolfhound puppies in Norway, from birth through age 10. Breeders and owners purchasing puppies filled out questionnaires about the puppies’ activities, growth and health. The puppies were also examined by veterinary surgeons and their hips X-rayed at ages determined by the kennel club – 12 or 18 months depending on breed.
Krontveit’s research may dispute previous research, as she found that the breed that grows the slowest, the Newfie, had the highest incidence of dysplasia at 36 percent. The Wolfhound, which grows the quickest, had the lowest risk of disease at 10 percent. These results surprised Krontveit and her fellow researchers, she says.
Her research also indicates that conditions at a breeder’s kennel or home have a bigger effect on the development of dysplasia in the future. Puppies born in spring or summer had a lower risk, as did those who had a chance to exercise in a park on a daily basis until 3 months of age. Those who walked up and down steps during the first three months had an increased risk of developing hip dysplasia. “Overall, it would appear that daily exercise out in gently undulating terrain up until the age of 3 months gives a good prognosis when it comes to preventing HD,” Krontveit concludes.
Owners filled out annual questionnaires so Krontveit could track the dogs’ health. In reviewing the effect of HD on the dogs, she found that Newfoundlands and Leonbergers seriously affected by dysplasia were euthanized sooner than Labrador Retrievers or Irish Wolfhounds. Symptoms, such as limping and hip pain, developed earliest in Newfoundlands and latest in Labs. The research also found that “varied exercise had a positive effect, and dogs that exercised on a daily basis on a lead and running free in different types of terrain were free of symptoms longer than dogs that were less active.”
Despite the fact that her findings are different from those of others who have researched hip dysplasia, she says that most of the response she’s gotten has been “very enthusiastic” and that other researchers are “very interested” in her research. “So far I have not gotten any negative responses,” she says.
Krontveit points out that the results of the study are not “definitive,” and “further studies on hip dysplasia etiology are certainly needed. Perhaps the most important finding of my research is that the period from birth until 3 months seems crucial, and further studies including this time period would be beneficial. Having said that, it might not be possible or necessary to find ‘all’ factors critical for hip dysplasia development. It would be good if results from research could be used to modify environment for young puppies and thus perhaps prevent disease.”
No one else is doing similar research at this time, to the best of Krontveit’s knowledge.