What is the latest in diagnosing and preventing hip dysplasia in dogs?
Hip dysplasia is one of the leading causes of arthritis in dogs, particularly in predisposed breeds like German Shepherds, Labradors, and Golden Retrievers and can start to cause issues as early as 6 months of age. This condition arises from various factors, but fundamentally, it stems from imperfect development of the hip joint, resulting in the gradual degradation of joint cartilage and the onset of arthritis. As the joint remodels over time, affected dogs can experience significant pain during routine movements. In moderate to severe cases, ongoing pain management becomes essential for maintaining the dog’s quality of life. However, when medication proves ineffective or unsuitable for long-term use, surgical intervention such as a total hip replacement becomes necessary to alleviate pain. Salvage procedures may suffice for smaller breeds but are often inadequate for larger breeds with hip arthritis. Treatment and prevention of hip dysplasia begins with an early diagnosis.
Enter the University of Pennsylvania Hip Improvement Program – better known as PENNHIP.
PENNHIP is a specialised series of x-rays considered the gold standard for predicting the likelihood of a dog developing hip dysplasia. These x-rays yield an objective value indicating the degree of hip joint laxity, with lower scores indicating tighter hips and higher scores indicating looser hips. This metric serves as the most reliable predictor of hip dysplasia and aids in identifying dogs eligible for preventive surgery. PENNHIP x-rays can be conducted at any age from 16 weeks. The results of the x-rays can help determine if a dog would benefit from preventative surgical interventions. Additionally, breeders should be considering using PENNHIP to make informed decisions regarding breeding practices. With evidence suggesting the heritability of both hip dysplasia and hip laxity (PENNHIP score), breeding dogs with favourable scores can potentially improve hip conformation over time.
To obtain the x-rays, dogs must be under a deep sedation or general anaesthesia and only veterinarians accredited by PENNHIP can perform this. These x-rays are then interpreted by specially trained radiologists at Antech Imaging in the US, the proprietors of the PENNHIP program. PENNHIP screening contributes to the broader goal of reducing the prevalence of hip dysplasia and associated arthritis in susceptible canine populations through selective breeding. On an individual level, it can help select those that would benefit from preventative surgeries.
The hips extended view allows us to assess the level of arthritis that may already be present and detect any other abnormalities. The compression view allows us to accurately calculate the “distraction index” which is how far the hips have moved from the neutral compressed position to the “distraction” position using the specialised distraction device from PENNHIP. Implementing preventative measures is the best way we can reduce the risk of a predisposed puppy from going on to develop hip dysplasia.
The first of these measures is a Juvenile Pubic Symphysiodesis (JPS). This a relatively straightforward and the least invasive procedure and involves early fusion of the pubic bone to facilitate proper pelvic growth over the hip joints. Studies have shown promising outcomes for dogs meeting the criteria for this surgery. Timing is critical, with the procedure ideally performed before 18 weeks of age for optimal results.
For cases where the window for a JPS has passed, the double or triple pelvic osteotomy (DPO/TPO) presents the next viable option, typically applicable up to 8 months of age depending on the breed. This more intricate procedure involves multiple pelvic cuts and plating to reposition the pelvis, thereby enhancing coverage of the femoral heads. This has comparable results to the JPS but is significantly more invasive.
Both JPS and DPO/TPO aim to pre-empt and essentially stop the onset of hip dysplasia, therefore minimizing the development of arthritis. Since clinical signs of lameness or pain may not manifest in the young dogs that require these procedures, objective selection criteria are imperative to identify suitable candidates for intervention. This is based on the PENNHIP score and/or palpation of the puppy’s hips.
At Tauranga Vets, we are PENNHIP accredited and have the expertise to perform the JPS procedure. Please don’t hesitate to get in touch if you have any questions about these procedures or anything else regarding hip dysplasia.
At Tauranga Veterinary Services we can see you and your beloved pet 7 days per week at our Tauranga Clinic and 6 days at our Te Puna, Katikati, Papamoa and Mount Maunganui Clinics. Book online at www.bopvets.co.nz or call 0800 838 7267 now to organise a booking convenient to you.