The Canine Health Schemes serve to provide dog breeders with the option of testing for certain inherited diseases, to enable them to breed only from dogs which have fewer or no signs of inherited disease and thus help to reduce the incidence of these diseases.
CANINE HIP DYSPLASIA (CHD)
The Labrador like most medium / large breeds the labrador has a predisposition to Canine Hip Dysplasia (CHD).
Currently the average hip score in Labradors is around 16.
This is achieved by an x-ray of the hips after which the film is sent to the BVA for examination. A point is added for each fault seen so the lower the number the better the hip score. A score of 0:0 is rare and remember 16 is an average so scores slightly higher than this are still acceptable.
Hip dysplasia literally means an abnormality in the development of the hip joint. It is characterized by a shallow acetabulum (the "cup" of the hip joint) and changes in the shape of the femoral head (the "ball" of the hip joint). These changes may occur due to excessive laxity in the hip joint. Hip dysplasia can exist with or without clinical signs.
Hip dysplasia is a developmental condition and is not considered a congenital anomaly. Dogs with hip dysplasia appear to be born with normal hips and then to develop the disease later. This has led to a lot of speculation as to the contributing factors which may be involved with this disease. This is an inherited condition, but not all dogs with the genetic tendency will develop clinical signs and the degree of hip dysplasia which develops does not always seem to correlate well with expectations based on the parent's condition. Unlike many other genetic disorders, however, the occurrence of hip dysplasia cannot be traced to a single gene; it is polygenic (caused by many genes). As with other polygenic disorders, external environmental factors play over a 60% role in the expression and degree of hip dysplasia. In other words how the dogs are looked after during the crucial growth period.
In recent studies it has been observed that 2 out of 10 puppies born of so called HD-free parents will develop hip dysplasia. The risk increases to 5 out of 10 if one of the parents does in fact have hip dysplasia; 8 out of 10 will risk developing hip dysplasia if both parents are afflicted.
At present, the strongest link to contributing factors other than genetic predisposition appears to be to rapid growth and weight gain. In a recent study done in Labrador Retrievers a significant reduction in the development of clinical hip dysplasia occurred in a group of puppies fed 25% less than a control group which was allowed to eat free choice. It is likely that the laxity in the hip joints is aggravated by the rapid weight gain.
The good news about Canine Hip Dysplasia is that most cases can be treated to help eliminate or decrease pain, allowing fairly normal levels of activity. Very few dogs today have to be put to sleep to alleviate suffering. There are always choices to be made, but the vast majority of affected animals can live quite comfortable lives.
For now, the best chance of avoiding the disease is still to select puppies from parents who both have normal hip joints, but this doesn't guarantee the puppy won't have dysplasia. Normal puppies may also be born to parents who have hip dysplasia. Like all of life, it still pays to get the best odds you can.
CANINE ELBOW DYSPLASIA (ED)
Elbow dysplasia is a common and often debilitating joint disease affecting many larger breed (usually pedigree) dogs. Affected dogs have a genetic tendency to develop the disease but the severity of the disease can be influenced by other factors. The Kennel Club (KC) introduced the elbow dysplasia scoring scheme to identify affected dogs at an early stage so that they could be prevented from breeding and passing the condition to their puppies. The scheme has been widely adopted by several breed societies.
X-rays of both elbows are examined by veterinary specialists for signs of disease. Points are awarded for changes seen in the elbows and these points are added together to produce the score.
Four grades are possible for each elbow:
- 0 = unaffected
- 1 = mild changes
- 2 = moderate changes
- 3 = severe changes
The overall grade of the dog is that of the higher graded elbow.
LABRADOR CENTRONUCLEAR MYOPATHY (CNM)
Centronuclear Myopathy (CNM) is a disease that has been of concern in Labrador Retrievers since the 1970’s. CNM is found in both field and conformation (showline) Labradors in the United States, Canada and the United Kingdom as well as many other countries globally. Research has confirmed that the disease is identical in all countries.
Centronuclear Myopathy (Muscular Myopathy of the Labrador) is a disabling disease affecting Labrador Retrievers that has been described for 30 years. The number of affected dogs varies and depends upon which studs and dams have been used for breeding. Often a popular Labrador might be a carrier, but it is only discovered after many litters of pups have already been produced. Recently the numbers of affected litters appear to be increasing.
CNM clear Labradors are placed on an International Registry – (White List). It is continuously updated with names of newly tested and cleared dogs. This positive information should provide a tool to help safely breed dogs. Safe breedings will protect us from pups being affected by this debilitating disease.
Exercise Induced Collapse (Eic)
Exercise Induced Collapse is an inherited condition that affects Labrador Retriever and related breeds. Affected dogs can endure mild to moderate exercise but after 5 to 20 minutes of heavy exercise with extreme excitement, the dog shows weakness and then collapse. Severely affected dogs may collapse whenever they are exercised to this extend – other dogs only exhibit collapse episodes sporadically.
Signs of EIC are not typically seen until the dog begin intense training. First symptoms are usually noted between 5 months and 3 years of age. However, it is confirmed that some affected dogs did not have collapse episodes until as late as age 10.