Hip dysplasia is a developmental disorder characterized by the abnormal formation of the hip joint, where the ball (femoral head) and socket (acetabulum) do not fit together properly. Over time, this misalignment leads to joint instability, which can cause painful arthritis, reduced mobility, and, in severe cases, crippling lameness. It is one of the most prevalent skeletal disorders in dogs and remains the leading single cause of hip arthritis in canines. Though it can occur in various species, including humans, it is most commonly associated with dogs—particularly large and giant breeds like German Shepherds, Labrador Retrievers, and Saint Bernards.

The Collie has a relatively low incidence of hip dysplasia. According to the Orthopedic Foundation for Animals (OFA), only about 2.8% of Collies are affected. Despite this low rate, responsible breeders often screen their dogs using X-rays to maintain and improve the breed’s orthopedic health.

This condition is polygenic, meaning it is influenced by multiple genes rather than a single dominant or recessive gene. While hip dysplasia is hereditary, environmental factors such as rapid growth, excessive weight, poor nutrition, and overexertion during puppyhood can exacerbate its development.

Diagnosis is made through radiographic imaging. To obtain accurate X-rays, the dog’s hips must be positioned precisely. This may require sedation to ensure proper alignment and minimize discomfort.

Two primary systems are used to evaluate and categorize hip health:

• Orthopedic Foundation for Animals (OFA) – Provides a subjective grading based on radiographs taken at 24 months or older.
• Antech Imaging Service (AIS) PennHIP – Uses a more quantitative method to measure hip laxity and can be performed as early as 16 weeks of age.

Elbow dysplasia is another common orthopedic condition, particularly in large and fast-growing breeds. It involves abnormal development of the elbow joint, which is made up of three bones: the humerus, radius, and ulna. When these bones do not align properly, it leads to joint incongruity, uneven pressure distribution, and eventual cartilage damage.

There are several specific conditions that fall under the umbrella of elbow dysplasia:

• Fragmented Coronoid Process (FCP) – A small piece of bone breaks off inside the joint.
• Ununited Anconeal Process (UAP) – A growth plate fails to fuse properly.
• Osteochondritis Dissecans (OCD) – A cartilage defect that can cause loose flaps in the joint.
• Elbow Incongruity – A general mismatch in the shape or length of the bones forming the elbow.

Symptoms often appear between 5 and 18 months of age and include front limb lameness, stiffness, reluctance to play, and swelling around the elbow. Like hip dysplasia, diagnosis is made via X-rays or advanced imaging like CT scans, and treatment may involve medication, physical therapy, or surgery.

Early detection of both hip and elbow dysplasia plays a crucial role in improving long-term outcomes for affected dogs. Identifying these conditions before significant joint damage occurs allows for timely intervention, which can slow the progression of arthritis, reduce pain, and preserve mobility.

Through early screening, veterinarians and owners can implement proactive strategies such as weight management, controlled exercise, joint supplements, and in some cases, corrective surgery. These measures can significantly enhance a dog’s quality of life and may even prevent the need for more invasive treatments later on. Moreover, early diagnosis supports responsible breeding practices by helping to reduce the incidence of these hereditary conditions in future generations.

The Collie Health Foundation supports owners who test their dogs’ hips using either OFA or PennHIP by covering the submission costs associated with these tests.

Read more about our Hip and Elbow grading subsidy here.

Watch the 2019 CHF Seminar on Hip & Elbow Dysplasia, OFA and PennHIP by Dr. Nancy Kelso, DVM

The OFA classifies hip joints into seven categories, based on the degree of joint congruity, the presence of arthritic changes, and overall joint health. Dogs must be at least 24 months old to receive a final OFA hip grade, and the evaluation is performed by a panel of three board-certified veterinary radiologists.

Normal Grades (suitable for breeding):

1. Excellent – The hip joint is perfectly formed with a deep, well-rounded socket and a tight fit of the femoral head. There are no signs of looseness or degeneration.
2. Good – The hip joint is well-formed with minor deviations from ideal structure. The ball fits snugly in the socket, and there are no signs of arthritis.
3. Fair – The hip joint is slightly less congruent, with a looser fit than Good or Excellent, but still within normal limits. No arthritic changes are present.

Borderline Grade:

4. Borderline – The hip joint shows minor irregularities that are not clearly normal or dysplastic. No definitive arthritic changes are seen, but the joint may be re-evaluated after 6 months.

Dysplastic Grades (not recommended for breeding):

5. Mild Dysplasia – There is some joint incongruity, with a shallow socket and possible early signs of arthritis such as small bone spurs.
6. Moderate Dysplasia – The femoral head is partially out of the socket, and there are clear signs of joint degeneration and arthritic changes.
7. Severe Dysplasia – The femoral head is significantly displaced from the socket, with extensive arthritic changes, bone remodeling, and joint deformity.

Images from the Orthopedic Foundation for Animals

The PennHIP (University of Pennsylvania Hip Improvement Program) method is a radiographic technique that measures the passive laxity (looseness) of a dog’s hip joints. Unlike the OFA system, which provides a subjective grade based on joint appearance, PennHIP offers a quantitative measurement called the Distraction Index (DI).

PennHIP requires three specific radiographic views:

1. Compression View – Shows how well the femoral head fits into the socket under pressure.
2. Distraction View – Measures how far the femoral head can be displaced from the socket.
3. Hip-Extended View – Similar to the traditional OFA view, used for comparison.

These views are taken under heavy sedation or anesthesia to ensure muscle relaxation and accurate measurements.

PennHIP Compression View

PennHIP Distraction View

Distraction Index (DI)

The DI is a number between 0 and 1, representing the degree of hip laxity:

• DI = 0: Perfectly tight hips (no laxity).
• DI < 0.3: Very low risk of developing osteoarthritis.
• DI > 0.3: Increasing risk of hip dysplasia and arthritis.
• DI ≥ 0.7: High risk; these dogs are very likely to develop degenerative joint disease.

The PennHIP method can be performed as early as 16 weeks of age, making it a valuable tool for early detection and breeding decisions. It is considered more predictive of future hip health than traditional methods because it directly measures the joint’s mechanical stability

Treatment for hip and elbow dysplasia in dogs varies depending on the severity of the condition, the age of the dog, and the presence of arthritis or joint degeneration. In mild to moderate cases, conservative management is often effective and includes a combination of weight control, low-impact exercise, physical therapy, and joint supplements such as glucosamine and chondroitin. Pain relief medications prescribed by a veterinarian can significantly improve comfort and mobility.

In more advanced cases, surgical intervention may be necessary. For hip dysplasia, procedures like femoral head ostectomy (FHO), double or triple pelvic osteotomy (DPO/TPO), or total hip replacement (THR) are considered.

Elbow dysplasia may require arthroscopic surgery to remove bone fragments or correct joint incongruity.

Regardless of the approach, early and individualized treatment plans developed in consultation with a veterinarian can greatly enhance a dog’s quality of life and slow the progression of joint damage.