Diagnosing Hip Dysplasia in Dogs

Hip dysplasia in dogs is a developmental disease that may lead to arthritic changes, lameness and debilitating pain. The condition is a result of genetics and/or environmental conditions. Because of the hereditary component of the disease, any dog or puppy should be evaluated before purchase and before breeding. The most common methods of diagnosing canine hip dysplasia are physical exam and x-rays. X-rays provide data that is used in hip scoring. Hip scores are numerical indicators of the likelihood or presence of hip dysplasia.

Physical Exam for Diagnosing Hip Dysplasia in Dogs

Physical examination for canine hip dysplasia includes evaluation of signs and symptoms and palpation of the hip joints. Symptoms of canine hip dysplasia are subjective problems that are reported by the owner and may or may not be evidenced in the clinical exam.

These include:

  • difficulty rising from a lying or seated position
  • lethargy
  • limping
  • lack of desire to use stairs, jump, or use back legs
  • hopping like a rabbit
  • swinging of the rear when walking
  • pain when getting up or after activity

Signs are objective and are able to been seen or experienced by the physician. These include: back leg limp, refusal to jump or use back legs, swinging of hindquarters when walking, refusal to go up or down stairs, gait that resembles a rabbit hop, discomfort from touching or examining of the hip(s); decreased joint mobility; popping or cracking in the hip joint on palpation, positive Ortolani sign (a palpation exam for lax hip joints), positive Barden’s maneuver (the slippage of the femur out of the socket and back in again during palpation), and partial or complete dislocation.

X-Ray Diagnosis of Canine Hip Dysplasia

However, physical examination which results in no evidence of dysplasia is not in itself diagnostic. Dogs can show no physical evidence of hip dysplasia on physical exam and still have significant disease. For this reason, x-rays of the hips are more diagnostic of canine hip dysplasia that physical exams. X-rays are not without fault though, as e-ray evidence of hip dysplasia may not be evident in some dogs until the age of two years.

The PennHip x-ray technique has been in use since 1983 and involves the use of precise measurements of hip laxity while the dog is under anesthesia. The PennHip method can be used on dogs as young as 16 weeks of age. Since hormonal influences can affect hip laxity in females, it is recommended that the x-rays not be taken while a female is in heat, pregnant, or nursing a litter of puppies.

The PennHip method follows strict guidelines on anesthesia and positioning, making the data from all the x-rays in the series equal and eliminating false positives. The anesthesia allows for precise measurement as the muscles are completely relaxed and there is no movement from the animal. The degree of hip dysplasia when reported as a percentile value is ranked higher values indicating lesser degrees of dysplasia. When a DI (dysplasia index) is reported the lower the value the better. Values of 0.3 and above indicate either a high propensity for or active existing disease.