Hip dysplasia is the most common hereditary orthopedic disease in dogs. It consists of abnormal development of the coxofemoral joint that causes joint laxity, progressive cartilage degeneration and, over time, debilitating osteoarthritis. Although it can affect any breed, it is especially prevalent in large and giant breeds: German Shepherd, Labrador, Golden Retriever, Rottweiler and Bernese Mountain Dog top the statistics.
Causes and Risk Factors
Hip dysplasia has a multifactorial origin. Heredity is the most important component, but the development of the phenotype also depends on environmental factors:
- Genetics: the main cause. Selection of breeding dogs with certified hips (OFA system in the US, BVA/KC in the UK, SV in Germany) has reduced its prevalence in some breeding lines, but it remains high.
- Accelerated growth: overfeeding puppies of large breeds promotes rapid growth that exceeds joint developmental capacity.
- Inadequate exercise: excessive exercise in puppies (especially hard surfaces or climbing stairs before 3 months) increases risk.
- Overweight: increases mechanical load on the dysplastic joint.
Symptoms by Age
Dysplasia can manifest at two different times in the dog's life:
In puppies (4-12 months): intermittent lameness of the hindquarters, difficulty getting up, reluctance to exercise, "bunny hopping" (both hind legs move together when trotting), pain on hip palpation.
In adults and older dogs: secondary osteoarthritis causing chronic lameness, morning stiffness, progressive reduction in range of motion, hindquarter muscle atrophy and chronic pain affecting quality of life.
Diagnosis: Radiology as the Cornerstone
Definitive diagnosis requires a ventrodorsal pelvic radiograph in the standard position, ideally under sedation to relax the musculature and obtain a correct projection. The Norberg angle, the degree of femoral head coverage by the acetabulum and the presence of degenerative signs are evaluated.
The PennHIP (Pennsylvania Hip Improvement Program) test can detect joint laxity from 16 weeks of age and is more sensitive than standard radiography for predicting the development of osteoarthritis. It is the reference technique for selecting breeding dogs.
Treatment Options
Treatment depends on the dog's age, severity of dysplasia and whether osteoarthritis has already developed:
Conservative (medical) treatment: appropriate for mild-moderate cases or when surgery is not feasible. Includes weight control, physiotherapy and aquatic rehabilitation, veterinary non-steroidal anti-inflammatory drugs (NSAIDs), chondroitin and glucosamine supplements, and more recently, platelet-rich plasma (PRP) injections or mesenchymal stem cells with promising results.
Preventive surgery in puppies:
- Juvenile pubic symphysiodesis (JPS): minimally invasive procedure before 20 weeks that alters pelvic growth to improve acetabular coverage. Only effective in young dogs without established joint changes.
- Triple pelvic osteotomy (TPO/DPO): for dogs 5-10 months old with joint laxity but without osteoarthritis. Reorients the acetabulum to improve joint congruence.
Corrective surgery in adults:
- Total hip replacement (THR): replacement of the joint with a prosthesis. Provides the best long-term functional results in dogs over 20 kg. The success rate exceeds 95% in specialized centers.
- Femoral head and neck excision (FHO): a more economical and accessible alternative, especially in small and medium-sized dogs. The joint is supported by muscle and fibrous tissue, with variable results.
Prevention and Responsible Breeding
Reducing the prevalence of hip dysplasia requires breeders to only reproduce dogs with hips certified as free of dysplasia or with mild grades. Owners of predisposed breeds should avoid overweight from puppyhood, limit high-impact exercise before one year of age and perform a screening radiograph at 12-18 months, even in animals without symptoms.
