Posted Date: February 11, 2013
A study by Norwegian researcher Randi Krontveit indicates that conditions in early puppyhood can affect the appearance or severity of hip dysplasia in genetically predisposed dogs. Article by Claudia Bensimoun
There's probably no better subject on evidence-based dog health care than the benefits and risks of early-age preventive measures for hip dysplasia. Because hip dysplasia is a hereditary developmental disease in which the hip joint fails to develop properly, determining both the genetic and environmental factors would help eliminate the disease through informed breeding and training practices.
Although hip dysplasia is a hereditary condition, a recent doctoral research study by Randi Krontveit at the Norwegian School of Veterinary Science examined the role that environmental factors played in its development. Hip dysplasia is a genetic disease. Dogs are not born with hip dysplasia, but puppies that are genetically predisposed to it may develop it in varying degrees. The severity of hip dysplasia has an effect on when the dogs show symptoms of this disease and on how long they tend to live.
Any dog can develop hip dysplasia, but the condition is most common in large dogs such as the Newfoundlands, Rottweilers, Golden Retrievers, Saint Bernards, and German Shepherd dogs. Previous studies have indicated that rapid growth in a puppy and a high body weight were factors that increased the likelihood of developing hip dysplasia. But Krontveit's study showed something different.
Hip dysplasia (HD) in dogs is affected to a larger degree than previously believed by the environment in which puppies grow up. It is particularly during the period from birth to three months that various environmental factors appear to influence the development of this disease. During the puppy stage, preventive measures can therefore be recommended with a view to giving dogs disposed to the condition a better quality of life.
Another factor that may influence the development of hip dysplasia in dogs is exercise. Many breeders will advise against exercising a pup to prevent the development of orthopedic conditions. Nonetheless, veterinarians believe that gentle, low impact exercise can be beneficial for pups, but that all forced exercise beyond what a puppy would normally do should be avoided. Veterinarians maintain that running should be avoided until a puppy is physically mature, and that puppies should stay away from high impact sports such as jumping and agility. Both of these activities are believed to be traumatic on a puppy's immature joints.
Randi Krontveit's research indicates that rapid growth and high body weight in the first year of the pup's life did not result in an increased risk of hip dysplasia. The study finds that the breed with the slowest growth rate, the Newfoundland, had the highest incidence of hip dysplasia(36%). The Irish Wolfhound had the lowest incidence of hip dysplasia (10%), yet the highest growth rate.
Puppies live together with their mother at the breeder's home (or other location) for the first eight weeks of their life. Dr.Krontveit found several factors related to the living conditions at the breeder's were shown to have an influence on the incidence of hip dysplasia. The study suggests that puppies born in the spring or summer, and to breeders who lived on a farm or a similiar area, had a lower risk of developing hip dysplasia.
Then, after about eight weeks, the puppies began a new life with their owners. Through observations, Krontveit confirmed that the opportunity to exercise daily in parks up until the age of three months reduced the risk of hip dysplasia. But the daily use of steps during the same period increased the risk of hip dysplasia. The study reveals that daily exercise outdoors in gently undulating terrain up until the age of three months is very helpful in preventing hip dysplasia.
Five hundred privately owned dogs participated in this study. The four breeds included were the Newfoundland, the Labrador Retriever, the Leonberger and the Irish Wolfhound. The dogs involved in the research were tracked through questionnaires that were completed by the breeder and the new owner, as well as by examinations by veterinarians.
Krontveit's researchers followed up on the dogs until they reached 10 years of age. They found that dogs that were seriously affected with hip dysplasia were euthanized earlier than dogs that had a milder form of hip dysplasia. Newfoundlands and Leonbergers tended to suffer from the more serious forms of hip dysplasia. Hip dysplasia did not have such a large effect on the longevity of Labrador Retrievers or Irish Wolfhounds. Krontveit found that serious and moderate degrees of hip dysplasia increased the risk of all hip dysplasia symptoms such as limping and hip pain and that these symptoms occurred the earliest in the Newfoundlands. Labrador Retrievers was the breed in which symptoms appeared much later on in life.
Labrador Retrievers, like this one, were one of the breeds used on Krontveit's study. Photo courtesy of Marit Stormoen.
Through observations, Krontveit confirmed that varied exercise had a positive effect and dogs that exercised on a daily basis on a leash as well as running free in different types of terrain were free of symptoms longer than the dogs that were less active. She adds that canine hip dysplasia in its most serious forms can be prevented, and that the life quality of dogs improves if preventative measures related to early canine life is introduced. "I also will highlight that the breeds included in our research are large breeds and that the results might not be directly transferable to small breeds," Krontveit says.
Unfortunately, older puppies do not benefit in the same way from free exercise. Krontveit says, "Based on our research, I can say that none of the exercise parameters we registered seemed to have any effect on hip dysplasia risk after approximately three months of age. [This means] that preventive efforts probably are most effective before this age. Having said that, I would still recommend that genetically prone pups should be exercised regularly to strengthen musculature, but extensive jumping/stair use, etcetera should be avoided until growth is completed (at approximately 12 months)."
To obtain more information about this research, you can contact Dr.Krontveit at firstname.lastname@example.org and visit www.nvh.no/en/Home/News/News-stories/A-number-of-environmental-factors-can-affect-the-incidence-of-hip-dysplasia-in-dogs/
Claudia Bensimoun is a freelance writer in West Palm Beach.