Canine Hip Dysplasia (CHD) is a prevalent inherited orthopedic condition affecting medium and large dog breeds, including popular choices like Labradors, German Shepherds, Rottweilers, and Bulldogs. This condition arises when the hip joint develops abnormally, resulting in looseness or laxity. Over time, this instability can lead to the development of arthritis, causing significant pain and discomfort for affected dogs. Fortunately, early diagnosis and prompt interventions often lead to the best possible outcomes for canine patients. While some dogs may only require minimal treatment, others may necessitate long-term medical management or surgical procedures. It is crucial that dogs diagnosed with CHD are never used for breeding to help mitigate the inheritance of this condition.
Causes of Canine Hip Dysplasia
CHD is primarily a genetic condition, but its expression can be significantly influenced by environmental factors such as nutrition and the rate of growth. Overfeeding and promoting rapid growth in puppies can exacerbate CHD in dogs already predisposed to the condition. Conversely, restricted growth may help reduce the manifestation of the trait. The inherent laxity in the hip joint caused by CHD eventually leads to the loss of cartilage, bony remodeling, and the subsequent development of osteoarthritis (OA).
Clinical Signs to Watch For
Dogs suffering from CHD may exhibit few or no outward signs in the early stages. However, some dogs can display symptoms as early as a few months old, while others might not show signs until later in life. The severity of the condition and the progression of arthritis play a significant role in when symptoms appear.
Common clinical signs include:
- Difficulty rising from a resting position.
- A characteristic “bunny-hopping” gait when running.
- Limping or stiffness in the hind legs.
- Reduced activity levels or an unwillingness to jump.
- Noticeable decrease in muscle mass in the hindlimbs.
- A swaying motion in the hips when walking.
- Shifting of weight towards the forelimbs.
Diagnosing Hip Dysplasia
The diagnosis of CHD is typically made through a combination of X-rays (radiographs), a thorough physical examination, and palpation of the hip joint, often assessed using the Ortolani sign. Specific positioning is required for accurate radiographic imaging, which usually necessitates sedation or anesthesia for the dog.
Two primary methods are commonly employed for radiographic evaluation of canine hips:
- PennHIP distraction method: Considered the most accurate technique for measuring hip laxity in puppies. This method requires veterinarians and technicians to be certified by the PennHIP organization and utilizes a specialized device.
- OFA (Orthopedic Foundation for Animals): Hips are graded based on radiographs taken after the dog reaches two years of age. While a provisional certification can be issued for dogs younger than two, the OFA radiograph may not accurately predict the subsequent development of osteoarthritis in puppies, potentially missing a crucial window for early treatment. Subtle changes in hip conformation can be challenging to detect, making a physical exam an essential companion to imaging.
A third diagnostic method, the Cornell dorsolateral subluxation method, examines a dog’s hips while the animal is in a kneeling position on the examination table. This method has shown a strong correlation with hip palpation findings, such as the Ortolani sign, thereby indicating hip laxity or instability.
Treatment Options for CHD
Treatment strategies for CHD are tailored to the severity of the condition, the dog’s age, and its response to various therapies. Many cases of CHD can be effectively managed medically, often following similar principles to the general management of OA in any major joint.
Key components of medical management include:
- Maintaining a healthy body weight: This is crucial, with dogs ideally exhibiting a visible waist when viewed from the side and from above.
- Nonsteroidal anti-inflammatory drugs (NSAIDs): These medications help manage pain and inflammation but require intermittent monitoring of blood work and other pain relievers may also be prescribed.
- Joint protective supplements and omega-3 fatty acids: These can support cartilage health and reduce inflammation.
- Regenerative medicine therapies: Options like stem cell therapy or platelet-rich plasma (PRP) may be considered.
- Regular, low-impact exercise: Activities such as walking and swimming are beneficial.
- Physical therapy: This can include muscle strengthening exercises, acupuncture, and other modalities.
For dogs with severe CHD who do not respond adequately to medical management, surgical options may be discussed with a board-certified veterinary surgeon. These are generally considered salvage procedures:
- Femoral head and neck ostectomy (FHO): This procedure is more commonly performed on small to medium-sized dogs.
- Total Hip Replacement (THR): While more costly than an FHO, THR is a more common and effective solution for large breed dogs.
In puppies diagnosed with CHD early, before the onset of OA, joint-preserving procedures may be recommended. These surgeries must be performed within a specific timeframe to maximize their chances of success:
- Juvenile Pubic Symphysiodesis (JPS): This minimally invasive surgery should ideally be performed between 12 and 20 weeks of age, with earlier intervention yielding better results.
- Triple Pelvic Osteotomy (TPO): This procedure involves placing implants in the pelvic bones and is best performed before the dog reaches orthopedic maturity, which for a Labrador Retriever-sized dog is around eight months of age.
Prognosis and Outcome
With appropriate care and management, dogs diagnosed with CHD can lead good quality lives, with the outcome largely dependent on the severity of the condition. Some dogs may require minimal support, while others will benefit from a multi-modal treatment approach. Maintaining a healthy weight and collaborating closely with your veterinarian to create a tailored treatment plan can significantly enhance a dog’s quality of life.
Dogs that undergo a Total Hip Replacement often regain a normal gait and range of motion. Following an FHO, dogs may experience a reduced or limited range of motion but generally achieve good function and outcomes, particularly those weighing under 40 lbs. JPS and TPO procedures can have excellent success rates if performed at the appropriate age, effectively eliminating joint laxity as the puppy matures.
Prevention Strategies
Responsible breeding practices are paramount in reducing the incidence of CHD in future generations. It is advisable to avoid breeding dogs with a known family history of CHD. Selective breeding should only occur after dogs have been radiographically screened for CHD. It is important to understand that a radiograph alone does not indicate genetic risk; a dog with normal hips can still produce offspring with CHD depending on its mate. Genetic risk can be more accurately assessed through pedigree analysis or progeny testing.
For breeds predisposed to CHD or symptomatic puppies, screening for hip laxity before 20 weeks of age via PennHIP is recommended. Early intervention with joint-preserving procedures such as JPS can prevent the development of severe CHD. Additionally, owners should avoid overfeeding, especially fast-growing puppies of large breeds, and strive to maintain a healthy weight throughout their dog’s life. Using properly formulated diets specifically designed for large breeds, particularly during growth phases, and avoiding unnecessary supplementation with calcium and vitamin D in growing puppies are also crucial preventive measures.
