Understanding Hip, Elbow & Shoulder Screening
For some health issues that are thought or known to have a strong genetic component but do not have DNA testing available, physical exams can instead provide the information that we seek.
Dysplasia is a disease characterised by instability within a joint which leads to pain and degenerative osteoarthritis. It is considered to be influenced by heredity, but environmental factors such as weight, rate of growth and exercise have a very strong influence. Treatments vary from lifestyle modifications through to a range of surgery options. Hip and elbow screening of parents is done in an effort to only breed animals with good joints together, hopefully minimising the risk to puppies of hereditary joint problems.
Currently there are two common radiographic predictive and/or diagnostic methods. We go into more detail below regarding standard hip and elbow scoring as recorded for the Dogs Australia/ANKC Canine Hip and Elbow Dysplasia Scheme (CHEDS) where x-rays are taken of ventro-dorsal flexed hips and lateral flexed elbows and assessed by a registered specialist radiologist, however many breeders also choose to have their dogs screened using the PennHIP system, which uses the same standard x-rays but also compression and distraction views to assess hip joint laxity. PennHIP x-rays may only be performed by accredited veterinarians and are all sent to the USA where they are assessed by a specialist radiologist and given a Distraction Index (DI) score between 0 and 1. A DI near 0 indicates little joint laxity (very tight hips) and a DI closer to 1 indicates a high degree of laxity (very loose hips). Dogs with tighter hips are less likely to develop hip dysplasia.
DI <0.3: No risk of hip dysplasia or arthritis and unlikely to ever have hip problems (except via accident) and are good candidates for breeding.
DI 0.3 - 0.7: Mild to moderate risk of hip dysplasia and arthritis. Dogs with a score above 0.3 should be carefully considered before breeding. Puppies under 20 weeks of age within this range are considered good candidates for a relatively minor, cost effective early intervention juvenile pubic symphysiodesis procedure to prevent the progression of hip dysplasia and avoid more costly surgical interventions or treatments such as hip replacements later in life.
DI >0.7: Arthritis is inevitable and discussion with your veterinarian regarding preventative management is strongly recommended.
PennHIP x-rays can be taken from 16 weeks of age and are considered the most accurate hip screening method available, whilst for the standard hip and elbow scoring dogs must be 12 months or over, and since all hips deteriorate to some extent over time, they are generally done between 1-3 years of age. X-rays of the joints are taken under sedation or general anaesthetic, with the films sent to a CHEDS panel radiologist for screening of any abnormalities (irregularities or poorly formed joints) and then allocated a score for each joint. Understanding these scores can be difficult for those unfamiliar with these reports and there is no guarantee that puppies will not develop hip or elbow dysplasia, however it is valuable information not only for breeders but also anybody looking to compete in the more high-impact dog sports such as agility, endurance and tracking, and buyers wanting to confirm that their puppy will hopefully start their growth with minimal genetic impact on their joints.
Elbows
The higher the number, the worse the joint. A grade is given for each elbow based on the millimetres of change, and the overall grade is determined by the higher of the two.
Grade 0: Radiographically normal
Grade 1: Mild osteoarthritis
Grade 2: Moderate osteoarthritis or a primary lesion with no osteoarthritis
Grade 3: Severe osteoarthritis or primary lesion with arthritis
It is recommended to only breed from dogs with an elbow score of 0.
Dysplasia is a disease characterised by instability within a joint which leads to pain and degenerative osteoarthritis. It is considered to be influenced by heredity, but environmental factors such as weight, rate of growth and exercise have a very strong influence. Treatments vary from lifestyle modifications through to a range of surgery options. Hip and elbow screening of parents is done in an effort to only breed animals with good joints together, hopefully minimising the risk to puppies of hereditary joint problems.
Currently there are two common radiographic predictive and/or diagnostic methods. We go into more detail below regarding standard hip and elbow scoring as recorded for the Dogs Australia/ANKC Canine Hip and Elbow Dysplasia Scheme (CHEDS) where x-rays are taken of ventro-dorsal flexed hips and lateral flexed elbows and assessed by a registered specialist radiologist, however many breeders also choose to have their dogs screened using the PennHIP system, which uses the same standard x-rays but also compression and distraction views to assess hip joint laxity. PennHIP x-rays may only be performed by accredited veterinarians and are all sent to the USA where they are assessed by a specialist radiologist and given a Distraction Index (DI) score between 0 and 1. A DI near 0 indicates little joint laxity (very tight hips) and a DI closer to 1 indicates a high degree of laxity (very loose hips). Dogs with tighter hips are less likely to develop hip dysplasia.
DI <0.3: No risk of hip dysplasia or arthritis and unlikely to ever have hip problems (except via accident) and are good candidates for breeding.
DI 0.3 - 0.7: Mild to moderate risk of hip dysplasia and arthritis. Dogs with a score above 0.3 should be carefully considered before breeding. Puppies under 20 weeks of age within this range are considered good candidates for a relatively minor, cost effective early intervention juvenile pubic symphysiodesis procedure to prevent the progression of hip dysplasia and avoid more costly surgical interventions or treatments such as hip replacements later in life.
DI >0.7: Arthritis is inevitable and discussion with your veterinarian regarding preventative management is strongly recommended.
PennHIP x-rays can be taken from 16 weeks of age and are considered the most accurate hip screening method available, whilst for the standard hip and elbow scoring dogs must be 12 months or over, and since all hips deteriorate to some extent over time, they are generally done between 1-3 years of age. X-rays of the joints are taken under sedation or general anaesthetic, with the films sent to a CHEDS panel radiologist for screening of any abnormalities (irregularities or poorly formed joints) and then allocated a score for each joint. Understanding these scores can be difficult for those unfamiliar with these reports and there is no guarantee that puppies will not develop hip or elbow dysplasia, however it is valuable information not only for breeders but also anybody looking to compete in the more high-impact dog sports such as agility, endurance and tracking, and buyers wanting to confirm that their puppy will hopefully start their growth with minimal genetic impact on their joints.
Elbows
The higher the number, the worse the joint. A grade is given for each elbow based on the millimetres of change, and the overall grade is determined by the higher of the two.
Grade 0: Radiographically normal
Grade 1: Mild osteoarthritis
Grade 2: Moderate osteoarthritis or a primary lesion with no osteoarthritis
Grade 3: Severe osteoarthritis or primary lesion with arthritis
It is recommended to only breed from dogs with an elbow score of 0.
Hips
Each hip joint is scored on 9 parameters, generating a total score representing the severity of the condition. The parameters and maximum score for each are as follows:
Each hip joint is scored on 9 parameters, generating a total score representing the severity of the condition. The parameters and maximum score for each are as follows:
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Primary Changes
Assesses the conformation of the hip joint - the poorer the fit of the femoral head (ball) to the acetabulum (socket), the more dysplastic the hip.
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Secondary Changes
Assesses the arthritic response to the underlying dysplasia in various parts of the joint. Likely to increase as the dog ages and the arthritis progresses.
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Normal Hips - Veterinary Information Network
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Hip Dysplasia - Veterinary Information Network
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The minimum score for each hip is therefore 0 and the maximum is 53. Hip scores should be balanced (similar on both sides), and the total score (both hips together) should be at or under the Breed Median Score (BMS), which for Border Collies in Australia is currently 7 as at November 2024. Traditionally, for breeding purposes ideally the total score should be 10 or under. When scores are markedly unbalanced, the worse score should be considered more indicative of the state of the dog's hips, and to achieve a realistic total for the purposes of breeding you should double the other side score before adding them up for a total.
Total Score 0 - 4: Perfect/near perfect hips
Total Score 5 - 10: Borderline changes that are unlikely to worsen with age
Total Score 11 - 20: Mild changes that may worsen with age, sometimes developing into osteoarthritis
Total Score 21 - 50: Moderate to marked hip dysplasia in which osteoarthritis is already a prominent feature, or severe hip dysplasia before an arthritic change
Total Score 51+: Severe to very severe osteoarthritis secondary to hip dysplasia
Total Score 0 - 4: Perfect/near perfect hips
Total Score 5 - 10: Borderline changes that are unlikely to worsen with age
Total Score 11 - 20: Mild changes that may worsen with age, sometimes developing into osteoarthritis
Total Score 21 - 50: Moderate to marked hip dysplasia in which osteoarthritis is already a prominent feature, or severe hip dysplasia before an arthritic change
Total Score 51+: Severe to very severe osteoarthritis secondary to hip dysplasia
Example: CHED (Canine Hip & Elbow Dysplasia) Scheme Certificate as reported by one of the radiologists on the panel who has viewed this dog's X-rays. The scores for both sides (4:3) are added together for the final score (7), and the current average and median scores are also shown for the breed as a point of comparison. This is a fairly balanced score with not much variation between each hip. A dog could also score a total of 7 with 1:6 hips, which would be considered more unbalanced and perhaps inform potential breeding or competitive decisions with the 6 becoming the most likely indication of the hips, with the 1 doubled for a total score of 8 instead. This is a mild example and needs to also take into consideration external factors such as any injury history.
Osteochondritis Dissecans (OCD) is an inflammatory joint condition causing mild to severe pain, reduced weight bearing, limping or lameness in the affected leg(s). Symptoms may only present after exercise depending on the severity of the case. During normal bone growth, cartilage is formed before being replaced by bone in a process called endochondral ossification. A dog with this condition will have abnormal cartilage growth in the joint (osteochondritis), with excessive, thickened cartilage which loses its blood supply, making it soft and weak which may cause it to crack, form a flap, or separate from the bone completely (dissecans). In Border Collies this most often occurs in the shoulders, however it may also affect the stifle (knee), hip, hock or elbow. If one of these other joints is affected, it is recommended to also investigate hip or elbow dysplasia and patellar luxation.
Often seen in rapidly growing large or giant breed dogs between the ages of 6 to 9 months (although it can present in dogs as young as 3 months old) and occurring more often in males, it is thought to have a hereditary component however this is as yet unproven. Known environmental factors are rapid growth causing inadequate blood supply during development creating lesions which contribute to a lack of proper bone formation in the area, and injury/trauma. Some studies have indicated that high calcium and protein in early nutrition may be a factor (linked to rapid growth). As with many other joint issues it is likely that multiple factors play a role in the development of the condition.
OCD is investigated and diagnosed via x-ray imaging under sedation or general anaesthetic, and in some cases an ultrasound of the joint or arthroscopic examination may be required. It is strongly recommended by our club that all breeding dogs are screened for OCD at the same time as they have their standard hip and elbow scoring x-rays performed and informed decisions made to continue efforts towards limiting unwanted hereditary conditions being passed on wherever possible. Avoiding environmental risk throughout any dog's growth and development is vital, such as jumping, too much exercise, exercising on hard surfaces and high-impact games such as fetch. Aim for a diet that does not promote unnecessarily rapid growth (high in calories/calcium), as periods of fast growth are typically when this condition usually occurs.
Often seen in rapidly growing large or giant breed dogs between the ages of 6 to 9 months (although it can present in dogs as young as 3 months old) and occurring more often in males, it is thought to have a hereditary component however this is as yet unproven. Known environmental factors are rapid growth causing inadequate blood supply during development creating lesions which contribute to a lack of proper bone formation in the area, and injury/trauma. Some studies have indicated that high calcium and protein in early nutrition may be a factor (linked to rapid growth). As with many other joint issues it is likely that multiple factors play a role in the development of the condition.
OCD is investigated and diagnosed via x-ray imaging under sedation or general anaesthetic, and in some cases an ultrasound of the joint or arthroscopic examination may be required. It is strongly recommended by our club that all breeding dogs are screened for OCD at the same time as they have their standard hip and elbow scoring x-rays performed and informed decisions made to continue efforts towards limiting unwanted hereditary conditions being passed on wherever possible. Avoiding environmental risk throughout any dog's growth and development is vital, such as jumping, too much exercise, exercising on hard surfaces and high-impact games such as fetch. Aim for a diet that does not promote unnecessarily rapid growth (high in calories/calcium), as periods of fast growth are typically when this condition usually occurs.
Main Joints Affected by Osteochondritis Dissecans. Joy of Pets (Jope)
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Diagram showing 'Dissecans', a fragment of bone separated from the shoulder joint as a result of Osteochondritis. VCA Animal Hospitals
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