Health Problems in Labrador Retrievers

Although Labs are generally healthy, as a breed they are susceptible to a few genetic health problems: hip and elbow dysplasia, Progressive Retinal Atrophy, exercise induced collapse (EIC).

Hip Dysplasia
Canine hip dysplasia (CHD) results from poor development of the hip joint and affects dogs of many different breeds. It is inherited, but because of the polygenic ("multiple genes") mode of inheritance it has proven to be difficult to eradicate. For example, it is possible for two dogs with "good" hips to produce a puppy with CHD. Additionally, environmental factors, such as trauma or excessive growth, can contribute to the problem.
The severity of CHD can vary from mild with no symptoms to severe and crippling arthritis. The first signs generally appear before a dog's first birthday and may only appear as a slight irregularity in gait. Young, affected dogs can improve somewhat as they mature and develop a stronger musculature, but even these dogs will develop arthritis later in life.
Diagnosis can be made by x-ray as early as 4 or 5 months of age, although at this age there is a small chance of error. All dogs intended for breeding should be x-rayed once they have matured, but before being bred for the first time. Twenty-four months of age is considered the minimum age for an accurate determination and for certification. Bitches should not be x-rayed within about four weeks before or after her heat cycle because the additional hormones circulating in her system at this time may cause a false positive reading.
X-rays are sent to Prof. Kirberger or Wagner (veterinary radiologists) who will determine whether or not the dog is dysplastic and will also assign a rating. Non-dysplastic hips will receive a rating of Excellent, Good, or Fair. Dysplastic hips will receive a rating of Mild, Moderate, or Severe.
Although the Lab is ranked as the most popular breed in South Africa, it was ranked 67th in the number of dysplastic dogs. Breeders are slowly making headway toward eradicating this problem.
Breeding only unaffected dogs probably accounts for the majority of the improvement. However it is wise to do everything possible to prevent CHD, therefore we recommend the following: Only breed unaffected dogs and only buy puppies from unaffected parents. Line the whelping box with carpeting or towels instead of newspapers to provide better traction. Prevent excessive jumping (e.g. into the back of a pickup) or forced exercise (e.g. roadwork) until the dog is mature (at least 24 months). Keep dogs on the lean side, instead of obese. Provide a good quality diet.

Elbow Dysplasia
Elbow dysplasia (ED) is a general term for various inherited abnormalities of the elbow. These abnormalities are: fragmented coronoid process of the ulna (FCP), osteochondrosis dessicans (OCD), and ununited anconeal process (UAP). They can occur separately or in any combination. Both elbows are affected in about 20 to 35 percent of affected dogs.
A dog with ED will typically show foreleg lameness between five to 12 months of age, but some dogs may not appear lame until much later in life. Some dogs may have obvious pain, while other affected dogs have an abnormal gait. The lameness or abnormal gait may be sporadic. Additionally the problem may appear worse after increased exercise, jumping or sharp turns.
In addition to lameness, other signs of elbow dysplasia include front legs that are rotated inward with the elbows sticking out and a decrease in the range of motion. Less commonly seen are muscle atrophy and joint capsule thickening.
Most cases of elbow dysplasia can be confirmed with x-rays. Multiple views are taken, and generally both elbows should be checked. X-rays are sent to Prof. Kirberger or Wagner (veterinary radiologists) who will determine whether or not the dog is dysplastic and will also assign a rating.However some cases of FCP may be difficult to diagnose using x-rays because of the relatively small size of the coronoid process. In these cases a CT scan may be useful.
Treatment consists of surgery for some animals, in addition to pain medication. Unfortunately only about half of the dogs that are treated medically and/or surgically will have a satisfactory long-term recovery because arthritic changes will continue throughout the dog's life. Early treatment seems to be the most successful. Swimming can help build muscles to improve joint stability without undue strain on the joint. Weight reduction may also help reduce strain. For young dogs, modifying food intake to keep the growth rate at a minimum may be helpful.
Although scientists are studying the causes of elbow dysplasia, results have been varied. Like hip dysplasia, it is believed to be polygenic ("multiple genes"), but environmental factors can also contribute. Some of these factors may include excess weight, consuming excess protein or calcium, rapid growth rate, excessive exercise, and trauma.

Progressive Retinal Atrophy (PRA) and other eye problems
Labs are also at risk for several eye problems including: PRA, cataracts, and retinal dysplasia. Eyes should be tested at the Animal Eye Hospital by Dr. Goodhead. The eye certificate is valid for 12 months and should be repeated before every Breeding/Mating.
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.
A genetic test is available for the prcd form of PRA (the only form found in Labradors). Your vet would need to draw a blood sample from your dog and submit it for the DNA test to Inqaba Biotechnical Industries.
Cataracts are relatively common in dogs. Most are hereditary, however haziness or cloudiness in the eyes of an older dog is often not caused by cataracts. Some cataracts are stable while others may progress in severity. Surgery can often help dogs with severely impaired vision.
Retinal dysplasia (RD) or "folds" In mild cases, sight is only slightly affected. In severe cases the dog may be blind and have skeletal abnormalities. Because RD may disappear with age, it is important to have puppies checked by a board-certified ophthalmologist, preferable between eight to ten weeks of age. At this time, folds are more easily detected. As the puppy grows the folds may straighten out and become almost impossible to diagnose. Dogs with any type of RD should not be bred.

Exercise Induced Collapse (EIC)
Labrador, Chesapeake Bay and Curly Coated Retrievers can be affected by a genetic problem causing collapse. Affected dogs are often described as extremely fit and muscular. Although they can tolerate mild to moderate exercise, strenuous exercise combined with extreme excitement can induce weakness followed by collapse.
Signs start with a rocking or forced gait, followed by weakness in the rear legs. Some dogs continue to run while dragging their rear legs. Some dogs also exhibit weakness in their front legs. Some dogs lose their balance and fall over. Most dogs remain conscious.
It is important to stop all exercise at the first sign of in coordination or wobbliness. A few dogs have died during exercise or while resting just after the episode.
In Labs, this condition is genetic and inherited as a recessive gene. A dog with one copy of the gene (a carrier) would not show any symptoms, however he can pass the gene to his offspring. A carrier should only be bred to a dog clear of this gene to avoid producing an affected dog. An affected dog can also be bred, but should only be bred to a clear dog to avoid producing an affected dog. All puppies of an affected dog will carry the gene.
A genetic test is available from the Inqaba Biotechnical Industries.