HIP DYSPLASIA

Hip Dysplasia is a genetic disease that affects the hip joints of dogs. (It is also known as degenerative joint disease, arthrosis and osteoarthrosis) and can lead to pain and debilitation in your Labrador. When canine hip dysplasia (CHD) was first described in the 1930s, it was thought to be a rare condition. Dysplasia literally means abnormal, so hip dysplasia literally translates as abnormal formation of the hip socket.Despite years of research and the combined efforts of breeders to have their dogs x-rayed, it has been impossible to eliminate hip dysplasia from labradors.Hip dysplasia can be seen in dogs as young as five or six months of age. In others, symptoms do not develop until after the dog has matured.

What causes it?Hip dysplasia is a multifactorial trait, which means that a number of different factors can contribute to it. However, hip dysplasia is basically a genetic trait and will not develop if the hereditary factor is not there to begin with. Many factors work together to cause this disease, which is a combination of a dog genetically inclined to get this disease interacting with environmental factors that bring about the symptoms. These environmental factors can be not feeding the correct diet of puppy food for large breed dogs, along with obesity, high protein and calorie diets as well as environmental factors. All the programs invented to eliminate a genetic defect like canine hd didn�t lead to the FACT the we are now able to guarantee the production of Labrador Retrievers without hip dysplasia, or will in the near future. Even breeding with parents that are genotypically unaffected this can still occur as hd is a resessive gene and not determined by DNA testing. Thus it is possible that generations and generations of Labradors will be produced who are free from hd and ed while other Labradors from the same parents, but raised under less optimal environmental circumstances, will develop hd or ed.

There are many diseases which display the same symptoms as hip dysplasia, therefore the only true way to diagnose hip dysplasia is by a complete physical and neurological examination, and then x-ray of the hips.

Hip Scoring System

FCI GRADE OLD RSA GRADE DESCRIPTION

A1 0 Excellent Hips

A2 0 Good Hips

B1 0 Fair Hips

B2 1 Marginal Dysplasia

C1 1 Mild Dysplasia

C2 1 Mild to Moderate dysplasia

D1 2 Moderate dysplasia

D2 2 Moderate to severe dysplasia

E1 3 Severe dysplasia

E2 4 Very severe dysplasia

 

 

 

Incidence of Canine Elbow Dysplasia in South Africa

(Extracts of article by Prof. R. M Kirberger Dr. N Stander paper published in the Journal of the South African Veterinary Association, 2007)
Elbow dysplasia (ED) is the abnormal development of the elbow joint. It is an all-encompassing term that covers a range of conditions including fragmented medial coronoid process (FMCP), osteochondrosis (OC) and osteochondritis dissecans (OCD); these conditions may occur on their own or in combination with each other.
Elbow dysplasia is inherited as multi-factorial polygenic traits. Within the Rottweiler breed the existence of a major gene has recently been suggested. Heritability varies from 0.10�0.77 and males may have a higher heritability than females. While a hereditary linkage has been demonstrated, environmental factors also play a role in the development of ED and the subsequent arthrosis. These factors include overfeeding (i.e. high bodymass), high fat intake, excessive calcium and short bursts of exercise up to the age of 24 months.
Although diagnosis of this condition was recognised back in the 1970s in the USA, it was only in 1998 that radiological testing was introduced in South Africa. The Kennel Union of South Africa (KUSA) and South African radiologists have adopted the guidelines established by the IEWG for an elbow dysplasia grading scheme to help combat the effects of this often crippling condition on South African dogs. Regrettably Labradors are amongst the breeds that commonly suffer from this condition.
These guidelines are as follows:

Dogs to be a minimum of 12 months old and should preferably be done at this age.

Radiographs to be made simultaneously with the hip dysplasia certification radiographs to save on costs.

Radiographs only to be interpreted by qualified veterinary radiologists

Only a single maximally flexed good quality ML radiograph of each elbow to be made. It was decided to evaluate only a single view in order to limit costs and thus encourage greater participation in the scheme by dog breeders.

Osteophyte (bone spur) formation at very specific locations within the elbow joints are evaluated for size and graded as follows
Grade 1 (mild arthrosis): osteophytes <2 mm in size.
Grade 2 (moderate arthrosis): osteophytes 2�5 mm in size.
Grade 3 (severe arthrosis): osteophytes >5 mm in size.
In South Africa, results for 340 dogs tested indicated a 20.6% prevalence of elbow dysplasia

The benefit of breeding ED-free dogs is illustrated by the following mating probability results for 13,151 breeding pairs of dogs (primarily Labrador retrievers, Golden retrievers, Rottweilers and German shepherd dogs) with known elbow status of the Orthopaedic Foundation of America

Normal elbows × Normal elbows =12.2 % offspring affected with ED.

Normal elbows × Dysplastic elbows = 26.1 � 31.3 % offspring affected with ED.

Dysplastic elbows × Dysplastic elbows = 41.5 % offspring affected with ED

Statistics in South Africa are only now emerging as the awareness of the condition increases and more breeders are screening dogs. As of 2007, the Labrador ranked No. 12 of larger breeds in terms of incidence of elbow dysplasia screened through the Ondeerstepoort system. The total number of dogs tested was 340, the second highest of all breeds in the country.

Progressive Retinal Atrophy (PRA)
Labs are also at risk for several eye problems including: PRA, cataracts, and retinal dysplasia.

PRA is a progressive deterioration of the light-receptive area (retina) of the eye, and will result in blindness. Symptoms are subtle, often starting with night blindness and eye dilation. Typically the age of onset is between four to six years which makes it difficult to identify carriers and remove them from the breeding pool.

This disease is caused by a simple recessive gene. For the dog to be affected he must have two copies of this recessive gene. A dog that has only one copy of the gene is a carrier and will show no clinical symptoms, but can pass the recessive gene on to his descendants

Possible breeding outcomes when mating a normal dog to dogs with other statuses

Parent 1 genotype

Parent 2 genotype

NORMAL

CARRIER

AFFECTED

NORMAL

All normal

50% Normal

50% Carrier

All Carriers

 
 
 
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