BCCNSW

Hip Dysplasia (HD) & Elbow Dysplasia

 

Canine Hip Dysplasia

This article was prepared by Dr Marilyn A Gill BVSc MVM

Hip Dysplasia in dogs is a disease that is characterised by instability of the hip joint (laxity), pain and eventually degenerative joint disease. It is considered to be inherited as a polygenic character (that is many genes are involved) and may be modified by many nongenitic factors. These non genetic factors are diet, rate of growth, body weight and exercise. In one report, rapid weight gain in the first 60 days of life and the ultimate above average weight of the dogs was associated with a higher level of hip dysphasia than the control group.

The Important Facts About Hip Dysplasia

Hip dysplasia occurs in all breeds of dogs, without radiographic proof, no breeder can state that his or her dogs are free of hip dysplasia. Considering the total number and popularity of Border Collies in Australia, the numbers that have been radiographed and results published are appallingly low.

Selection pressure on the breed has changed. As a working breed, the Border Collie was selected for its working instinct and ability to work all day. This meant that soundness was one of the two most important criteria selected for and as a consequence good hips. Now our selection criteria includes coat, breed standard conformation, temperament, soundness, CL status and collie eye. Show and pet soundness does not equate with working soundness. We can not assume good hips because the dog appears sound in the ring or backyard.

Because of modern transport, chilled and frozen semen, a single stud dog can have a profound influence on the breed. It is possible for a fault to become established in a breed very quickly. (You only have to look at the Bull Terrier breed and the devastation caused by polycystic kidneys to appreciate how significant this risk is)

Current results in the Border Collie indicate that the incidence and severity of hip dysplasia is low, however severe cases have been seen.

As responsible breeders, for both the good of the breed and to meet our legal obligations of producing sound pups for sale, it is imperative that breeding stock be radiographed.

 

Breed Averages

Country

Number of dogs Radiographed

Best

Worst

Average

Australia

389

0

89

9.58

New Zealand

126

0

19

7.12

England

3704

0

89

13.59

Because there is no compulsion to present bad hips for scoring then these averages may be lower than the true average

The current method of scoring is based on an extended view of the hips. The AVA has tried to address the discrepancies that occur between readers and have instigated a review panel. A newer method, the Pen Hip Score, measures the laxity of the hip. Currently the radiographs for the Penn Hip System can only be done by veterinarians trained and licensed by the American Company that devised this system. In addition the scoring is done in America. Time and peer review will probably validate this as a more accurate method of assessing dogs for hip dysphasia.

Undoubtedly there is a risk associated with a general anaesthetic, which is required for both the AVA and Penn Hip System. This is true in both human and veterinary medicine. No veterinarian can give you a 100% safety guarantee. We all love our dogs and would hate anything to go wrong. However young dogs with severe hip dysphasia being euthanased for a disease that we can help to prevent is more devastating.

 


 

Canine Elbow Dysplasia

This article was prepared by Dr R S Wyburn BVMS, DVR, PhD, FACVSc, MRCVS

Elbow dysplasia is a disease with a high inherited component, which primarily affects intermediate and large breed dogs. The incidence in Border Collies is low. Typically, both elbows are affected. However, unilateral elbow dysplasia is not uncommon.

DEVELOPMENT The elbow joint is formed by three bones (radius, ulna, and humerus) which must all grow synchronously and fit perfectly. The radius and ulna are paired bones with the radius being the main weight bearing bone. The normal elbow joint is characterized by a smooth transition from the ulnar articular surface to the radial surface. In a dysplastic elbow the edge of the ulnar surface lies above the level of the adjoining radius, creating a step between the radius and ulna and causing incongruity of the joint. The height of the step may vary from barely noticeable to 4 mm or more. When this occurs the weight bearing force on the ulna is increased, resulting in excessive pressure on the medial coronoid process. This leads to fragmentation of the coronoid process. The typical age for this to occur is between 5 and 7 months of age. A superficial to deeply grooved "kissing lesion" is often present on the humeral articular surface opposite the fragment. A cartilage flap or osteochondritis dissecans (OCD) lesion may also develop. Secondary arthritis becomes evident at 6-7 months. Compensatory adjustments during growth may occur in some dogs, tending to minimize unequal growth rates between the three bones and moving the ulna distally to better conform to the radius. . If the ulnar surface lies below the radial one, excessive force is then placed on the anconeal process at the top of the ulnar articular surface. This force will cause a failure of ossification, leading to an ununited anconeal process.

CLINICAL SIGNS

Affected dogs are frequently lame or have an abnormal gait. The gait is often characterized by excessive paddling or flipping of the front feet.

The animal may either hold the elbows out or tucked in and often stands with the feet rotated outward. Many sit or lie down much of the time, or play for shorter periods of time than other dogs of comparable age. They are often described as quiet or even lazy. Frequently, they are stiff when rising and tire easily. Exercise typically makes the lameness worse. In dogs with bilateral elbow dysphasia, the lameness may seem intermittent or shift from one front leg to the other. When both front legs hurt, dogs do not limp constantly. Rather, they shift weight off their elbows by altering their gait and stance. These dogs will only "limp" when one elbow is more painful than the other. On examination, manipulation of the elbow is often resisted. Swelling and crepitus (grating) may be palpated. The swelling may be worse after exercise. In some cases, the joint will be thickened. Muscle atrophy may also be present.

DIAGNOSIS

The routine monitoring for the presence of elbow dysplasia is carried out from a lateral x-ray of the flexed elbow joint taken when the dog is over 12 months of age. Correct radiographic technique is critical for making the diagnosis. The grade is derived by measuring the amount of new bone that has developed as a result of arthritis. Unlike the grading systems for hip dysplasia the system for elbow dysplasia is used internationally.

ADVICE

It is generally considered that dogs with grade 3 elbow dysplasia should not be used for breeding and that dogs with grade 2 should be considered a serious risk.

 

Reference: World Small Animal Veterinary Association web site

The information regarding OCD has been copied with permission from the NBCC website that was very kindly written by R S Wyburn BVMS, DVR, PhD, FACVSc, MRCVS.


Contact Details

 

President:                    Lauren Somers

                                     nahrof@iinet.net.au

Secretary:                    Ann Moy          

                                      secretary@bccnsw.com       

                                      (02) 6337 3393

Treasurer:                    Julia Lawrie    treasurer@bccnsw.com

Publicity Officer:         Ann Lenehan   publicity@bccnsw.com

Puppy Sales:               Ann Moy     puppysales@bccnsw.com

BC Rescue:                 Julie Gray  

                                      email: bcrescueaustralia@gmail.com 

                                      or check out www.bcra.org.au

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