What Is Canine Hip Dysplasia?
Hip dysplasia in dogs is an abnormality of the conformation of the hip joint that begins in their growing period as puppies. The hip is a ball and socket type joint that connects the leg to the pelvis.
Anatomically, hip dysplasia occurs when the indentation in the pelvis where the leg attaches (the socket) grows at a different speed than the ball (head of the femur).
In dogs affected with hip dysplasia, the uneven growth rate results in a hip joint that isn’t deep enough to cover the head of the femur. This leads to a loose joint that is prone to degenerative joint diseases such as osteoarthritis.
The joint’s deformity, laxity, and subsequent degenerative changes cause pain in the joint. Dogs express this pain via limping, being reluctant to jump and play, and sitting to one side or with their legs out behind them. These behaviors are an attempt to reduce the pain of the defective joint.
Dogs have different levels of pain tolerance, and a dog may have hip dysplasia even if they are not showing overt pain. It is also possible that a dog that is showing high levels of pain may only have mild hip dysplasia.
To obtain a diagnosis, x-rays of the hip joints must be taken. X-rays can give us a good idea about the hip joint’s conformation as well as alert us to the presence of osteoarthritis in the joint.
How Common is Hip Dysplasia in Dogs?
Hip dysplasia in dogs is extremely common, especially in larger-sized dogs. This is easily the most often diagnosed genetic orthopedic disease in dogs in general medical practices.
According to the Todhunter laboratory at the Cornell University College of Veterinary Medicine1, hip dysplasia is the most common orthopedic condition in medium and large-breed dogs. The university states that hip dysplasia is found at an incidence rate of up to 70 percent in some purebred dogs.
Any breed or size dog can develop hip dysplasia; however, the disease is seen most commonly in large dogs. The most commonly affected breeds are German Shepherds, Mastiffs, Saint Bernards, Labrador Retrievers, Rottweilers, Golden Retrievers, and Bulldogs. Keep in mind that mixed-breed dogs are also at risk.
What Causes Hip Dysplasia in Dogs?
Hip dysplasia is first and foremost a genetic disease. This means that hip dysplasia is passed from parents to their offspring. However, beyond simply having the genetic predisposition, other factors such as nutrition, exercise, weight, and hormones play a role in hip dysplasia in dogs.
One of the most vital factors in the development of hip dysplasia is nutrition. Medium and large sized breed puppies must be kept at a lean weight and not overfed.
Free feeding and feeding to rapidly increase a puppy’s size are two of the biggest causes of hip dysplasia. Dog breeds at risk of hip dysplasia should be meal fed and given adequate nutrition to grow but never overfed to try to increase their size prematurely.
Large breed puppies such as those listed should be fed carefully during their first year and not allowed to grow too fast or to become overweight.
Symptoms of Hip Dysplasia in Dogs
Typically, the first signs of hip dysplasia in dogs are weakness or pain in the hind legs. These can be manifested in various ways.
Dogs with early hip dysplasia may appear to have difficulty controlling their hind legs and may stumble or fall. Dogs with the disease also commonly have difficulty getting up from lying down, especially on hard or slippery surfaces.
Other dogs may limp or be reluctant to climb stairs. A “bunny-hopping” gait where the dog moves both hind legs forward at the same time while running often is seen with hip dysplasia.
While at rest, many affected dogs will sit with their hind legs to one side to take pressure off their hips or lie with both hind legs extended behind their body.
Typically, dogs with hip dysplasia will begin to show signs between three and six months of age. However, the early signs of hip dysplasia may be mild and easily missed.
Diagnosis of clinical hip dysplasia usually occurs in dogs between one and two years of age. Some mildly affected dogs may not show signs of the disease until they are older and develop osteoarthritis in their hip joints.
Diagnosing Hip Dysplasia in Dogs
If a dog is suspected of having hip dysplasia, the dog’s veterinarian will perform a complete orthopedic exam which will look for looseness or pain in the hip joints.
Hip dysplasia is most commonly diagnosed via x-rays of the dog’s hips, though CT scans may also be used.
Dogs should be sedated or put under general anesthesia to allow for accurate x-rays that will show any abnormalities in the hip joints. Any movement during the procedure can make accurate diagnosis impossible.
Two organizations can assist in diagnosis – The Orthopedic Foundation for Animals (OFA) and The University of Pennsylvania Hip Improvement Program (PennHip). Your veterinarian will assist in taking the x-rays and will counsel the owner on submitting them to one of these programs if indicated.
Treatment of Hip Dysplasia in Dogs
Once a diagnosis of hip dysplasia is made, a treatment plan will be crafted to address the pet’s clinical signs, mobility issues, and pain. Treatment plans will differ according to the severity of the disease in the individual dog.
Often the first line of treatment will be non-steroidal anti-inflammatory medications. These drugs should have minimal to no side effects in healthy dogs and can relieve pain when given as needed.
Other medications will be prescribed as needed. A nutritional supplement, such as glucosamine and chondroitin, may also be added to the treatment plan to encourage healthy joints.
The dog’s diet and weight should be thoroughly evaluated. Being overweight is not only a factor in the development of hip dysplasia, but it also plays a significant role in worsening the pain and disability experienced by dogs with this condition. Owners of overweight dogs affected by hip dysplasia should make weight loss their number one priority.
Dogs with hip dysplasia need to be exercised daily, but the type of exercise should be carefully considered. Regular exercise will strengthen the muscles in the hind legs and relieve pain. However, dogs with hip dysplasia should not participate in highly concussive activities as this will place undue stress on the hip joints.
Walking on grass or other soft surfaces, going up and down gentle slopes, exercising in the sane, and swimming are all great activities for a dog with hip dysplasia.
Dogs with hip dysplasia should not run on hard surfaces such as pavement or concrete and should not be encouraged to jump or leap with balls or toys.
Another therapy modality to consider for a dog affected by hip dysplasia is physical therapy. Specially trained veterinarians can work with the dog using both passive and active exercises that will build muscle while supporting joint health. One such exercise is walking on an underwater treadmill.
Surgery may be an option in severely affected dogs and those who do not respond to traditional therapies. The most common surgeries performed to treat hip dysplasia are a total hip replacement and a femoral head ostectomy (FHO).
Other surgical procedures used to treat hip dysplasia include triple pelvic osteotomy (TPO), juvenile pubic symphysiodesis, and arthroplasty. Owners considering surgery as a treatment option for their dog should consult with an ACVS Board-certified veterinary surgeon who will be able to guide them to the best procedure for the individual dog.
Preventing Hip Dysplasia in Dogs
Hip dysplasia is best prevented through responsible breeding. Owners considering a new puppy should carefully research the breeds they are considering.
If a large breed dog is selected, owners should become knowledgeable about hip dysplasia and how to select a puppy with a lower chance of developing the disease. Speaking to a veterinarian before purchasing a puppy is highly recommended.
If a purebred large breed puppy is desired, the prospective owners should locate a responsible breeder and ensure that the breeder has screened their breeding animals for hip dysplasia. This is accomplished via OFA or PennHip testing on all parents and offspring. Only dogs without radiographic evidence of hip dysplasia should be bred.
Once a puppy is brought into the family, a veterinarian should be consulted right away, and an appropriate feeding plan and diet created. Feeding the puppy correctly will ensure the best chance of preventing hip dysplasia.
Additionally, puppies should not be over-exercised or allowed to participate in activities that may cause damage to growing joints. If there are any concerns about the young dog’s orthopedic health, an examination with their veterinarian should be scheduled as soon as possible.
1. Cornell University College of Veterinary Medicine. https://www.vet.cornell.edu/research/labs/todhunter-laboratory. Accessed December 17, 2021.