Genetic Diseases in Golden Retrievers

The second portion of the list includes additional genetic diseases that affect goldens and for which we screen. These diseases either have inconclusive screening methods or do not debilitate affected dogs.  Within the screening limitations, we attempt to breed only clear stock.

Part I

• Canine Hip Dysplasia (CHD)

• Idiopathic Epilepsy

• Subarterial Aortic Stenosis (SAS)

• Eye Problems

• Elbow Dysplasia

• Thyroid Abnormalities

• Canine von Willebrand's Disease (vWD)

• Other Genetic Problems

Part I

Canine Hip Dysplasia (CHD). CHD is a malformation or abnormal looseness of the hip joint.  Affected dogs may exhibit no symptoms or may be crippled from as young as eight weeks.  Dogs who are asymptomatic early in life often develop arthritis in the hip joints as they age. This disease is thought to be caused by a combination of genetic and environmental factors.  The mode of inheritance has not yet been determined but is thought to be polygenic (caused by the influences of many genes).

There are presently two methods of screening dogs for CHD, both of which require hip x- rays.  The most common screening is done through the Orthopedic Foundation for Animals (OFA) which issues clearances rating dogs EXCELLENT, GOOD, and FAIR.  It also grades degrees of dysplasia as MILD, MODERATE, and SEVERE.  Dogs with equivocal finds are considered BORDERLINE.  At Gaylan's, we breed only cleared dogs with ratings of excellent, good or fair.  OFA ratings are indicated by a number that looks like GR11111G24F.  This indicates the x-rayed dog is a golden retriever (GR) with a clearance number of 11111 and a rating of "Good" (G) who was x-rayed at 24 months (24) and is a female (F).  An excellent rating would be indicated by an E and a fair appears as an F after the rating number.

Recently, the University of Pennsylvania has introduced a procedure that provides information about a dog's hips but does not offer clearances. Instead, PennHip grades the dog's likelihood of developing CHD using a distraction index (DI).  We seek to breed dogs with a DI that puts them in the top 50 percentile for all golden retrievers.  Presently, the average golden DI is .55 so dogs with DIs of .54 and below are in this percentile.

Forty years of golden retriever history has also shown that breeding clear dogs is not enough to reduce the rate of hip dysplasia. Breeders must also seek to breed only dogs with pedigrees with both depth and breadth of clearances, and those who produce lower than average numbers of dysplastic puppies. Depth means that even dogs two, three, or four generations behind the sire and dam were shown to be free of dysplasia. Breadth of clearances means that many or most of the sire's and dam's siblings also had normal hip joint conformation. Gaylan's bitches have both depth and breadth of dysplasia-free pedigrees. We also monitor their production rates to insure we are producing high percentages of cleared dogs and seek only to breed to dogs with similarly disease-free pedigrees and production rates.

Idiopathic Epilepsy. Idiopathic epilepsy is difficult to diagnose but results in recurrent seizures which have no apparent environmental (e.g., poisoning or heat exhaustion) or physiological cause (e.g., brain tumor). Inherited epilepsy in goldens usually appears in dogs between one and three years of age but may occur as late as five. We will not breed any dog that has had seizures of an unexplained origin or who has a family history of idiopathic epilepsy. There is presently no registry or certification for epilepsy-free dogs.

Subarterial Aortic Stenosis (SAS) SAS is a restriction of the aorta, usually by a ring of fibrous tissue, just after it leaves the heart. This restriction results in a distinct murmur (due to backflow and turbulence), heart enlargement, and restricted blood flow.  As with CHD, affected dogs can be asymptomatic or severely crippled by this disease.  SAS can also lead to sudden death, even in very young dogs.  It is thought to be a genetic disease with a polygenic dominant mode of inheritance.  Since many goldens have innocent (non-SAS) murmurs as puppies, breeding adults must be cleared by a board-certified veterinary cardiologist.  We breed only dogs cleared of SAS. You can find a list of board-certified veterinary cardiologists at http://www.vetheart.com/bystate.htm.

Eye Problems. The most common eye problems of golden retrievers are bilateral, juvenile-onset cataracts and abnormalities of the eyelids/eyelashes.  Contrary to its name, juvenile cataracts may not appear until the dog is five or six years old. Thankfully, most golden retriever cataracts are quite small and have little or no effect on the dog. Eyelid abnormalities include an inward rolling of the eyelid (entropion, ectropion) and the existence of extra eyelashes on the inside of the eyelid (distichiasis, trichiasis). In addition, goldens may suffer from progressive retinal atrophy (PRA) and retinal dysplasia. The mode of inheritance for all of these diseases has not yet been determined. We breed only dogs who have been cleared annually by a board-certified canine opthamologist.

The Canine Eye Research Foundation (CERF) provides certifying numbers to dogs cleared annually.  CERF numbers are similar to OFA numbers except, since they must be repeated every year, they indicate the year and age of the cleared dog.  Thus, CERF GR1111/96-24 is a golden retriever (GR) with clearance number 1111 who was seen by an opthamologist in 1996 when he was 24 months old.

Part II.This portion lists additional genetic diseases that affect goldens and for which we screen. These diseases either have inconclusive screening methods or do not debilitate affected dogs. Within the screening limitations, we attempt to breed only clear stock.

Elbow Dysplasia..  In the past few years, goldens have also been identified as suffering from hereditary elbow dysplasia.  Similar to CHD, dogs affected with elbow dysplasia may be asymptomatic or may be so severely affected they need surgery. Since this is such a new disease, few older goldens have been screened. All Gaylans brood bitches will be screened but we may breed to sires without elbow clearances. The Orthopedic Foundation for Animals (OFA) provides clearance numbers for elbow dysplasia but does not provide ratings in the number, e.g. GR-EL1121.

Thyroid Abnormalities.  Goldens are increasingly affected by hypothyroidism (low thyroid). This disease can cause lethargy, weight gain, hair loss, and skin problems.  Less frequent but also problematic, hyperthyroidism (high thyroid) can cause dogs to be underweight and hyperactive.  Thyroid abnormalities are easily diagnosed using a blood test and can be controlled through daily, lifelong medication.  We screen all of our dogs for thyroid abnormalities.  Thyroid testing is done at a number of labs across the United States.  The most common ones you will see are from Cornell and the University of Michigan.

Canine von Willebrands Disease (vWD). vWD is a disease similar to hemophilia in humans.  Although fatal in some breeds, such as Doberman Pinschers, goldens are rarely seriously affected.  Screening for vWD in goldens remains inconclusive.  However, we screen all of our breeding stock and seek to breed only to goldens with NORMAL percentages for vWD (percentages greater than 70%). Only a few U.S. labs provide vWD screening.

Other Genetic Problems. Goldens are affected by other diseases with undetermined or poorly investigated genetic bases. These include osteochondritis dessicans (disease of the shoulder and elbow joints), panosteitis, allergies, cryptorchidism, missing teeth, and bad bites. In addition, temperament remains the top priority for good golden breeders. We make every attempt to breed only dogs free of the problems listed above and who possess the ideal golden temperament as outlined in the Standard of the Golden Retriever,

...possessing a personality that is eager, alert and self-confident. Friendly, reliable, and trustworthy.  Quarrelsomeness or hostility toward other dogs or people in normal situations or an unwarranted show of timidity or nervousness, is not in keeping with the Golden Retriever character.