Genetic Diseases in Golden Retrievers--
Updated 7/2010
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Despite this belief, we do seek to reduce the number of seriously affected dogs we produce. To do this, we:
- study the diseases affecting goldens and their underlying genetics,
- include our dogs in as many valid research programs as possible,
- are passionate and public supporters of open health registries for without them the breeders of purebred dogs will never control health problems,
- collect and release genetic data on all of our dogs and as many of their relatives and ancestors as we can, and
- rigorously screen our breeding stock, including DNA testing when appropriate and as it becomes available .
Health screenings are a critical part of our investigation into our breedings, both before and after. However, we acknowledge the inherent weakness of this process; most health screenings tell us only what the dog's health is at one period of time. They do NOT tell us the dog's lifetime risk OR its genetic makeup. DNA tests offer more potential but, at present, we have very few DNA tests available for golden retriever diseses.
As we make our breeding decisions, we keep in mind that there are no perfect dogs in the world. This point is so important, let me say it again...THERE ARE NO PERFECT DOGS! Breeding is a process of making tradeoffs and weighing risks. Therefore, we are avid students of genetics and seek to make our breeding decisions based on sound science not simply health clearances. We seek to manage risks since completely alleviating them is not possible. Therefore, there may be times that we won't breed to a dog with all of his clearances because we believe the risk of genetic disease is too great and there may be times when we do breed to a dog who lacks a clearance because we believe what he has to offer outweighs this gap.
You can be sure that we will discuss all of this thoroughly with you (probably more thoroughly than you would prefer :-)) and we will stand behind our decisions with our warranty. If you get one of our puppies, we will also ask you to support us in our program by submitting your pup to numerous genetic screening tests and providing us with the results.
We do a tremendous amount of work to reduce the risk of genetic defects but we don't want to mislead you--it is NOT possible to successfully avoid all genetic problems in a breeding program. To expect this of a breeder is foolhardy. Even with all of our efforts over the last three decades, we have experienced nearly every genetic problem on this list. (And we know that those we have no personal experience with are likely to show up in the future.) Breeding dogs, like any adventure in genetics, is a risky activity. At the present state of DNA testing, we cannot know the genetic makeup of our dogs thoroughly enough to avoid disease. But, we can study, test and discuss with the goal of limiting problems. We cannot promise you a perfectly healthy puppy but we can promise that we have used our experience and expertise to make sound judgements about genetic disease, that we have discussed the risks with you ahead of time, and that we will stand behind our puppies for their lifetime.
This first portion of this list identifies the diseases that we feel are of most concern to golden retriever breeders and owners, in order of our priority. Unfortunately, not all of these diseases have screening tests available but, where they are, we use them to guide our breeding decisions. We seek to select away from these diseases, if it is possible to know it ahead of time. We also seek, if possible, to breed dogs with a majority of relatives--siblings, parents, and ancestors--who are not affected. We will also honestly evaluate the potential for genetic problems in our breedings and provide that information to you.
In 2007, two eye diseases have roared onto the golden scene and are now a priority for us in our breeding program. They are progressive rod-cone degeneration Progressive Retinal Atrophy, known as prcd-PRA, and pigmentary uveitis. We are still developing our breeding strategy for these disease but we have added them into Part I below.
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, do not debilitate affected dogs or are easily treated.
- Cancer
- Idiopathic Epilepsy
- Inherited Heart Disease
- Canine Hip Dysplasia (CHD)
- Elbow Dysplasia
- Swallowing Disorders
- Pigmentary Uveitis (PU)
- prcd-PRA (eye disorder)
- Allergies, Hot Spots, Skin Problems
- Immune-related Problems
- Other Inherited Eye Disease
- Thyroid Abnormalities
- Shoulder Osteochondritis Dessicans (OCD)
- Canine von Willebrand's Disease (vWD)
- Other Genetic Problems
Part I
Cancer. Recent surveys show that cancer is the #1 cause of death in golden retrievers and that their cancer rates equal some of the breeds long thought to lead the way in incidents of cancer, such as Boxers. This may be the greatest tragedy of the golden retriever in the 1990s. Cancers such as hemangiosarcoma (cancer of the blood) and lymphosarcoma (cancer of the lymphatic system) lead the list of killers of goldens. The breed's average lifespan is now down to 10 1/2 years.
We strongly believe that goldens should be long-lived (12-16 years) and healthy and active during most of this time. However, there is no screening test for cancer so it is difficult to know if the dogs you are breeding to will live long and healthy lives. Our approach is to select bitches from lines where more than 75% of the dogs in the pedigree lived to at least 11 (longer than the golden average), to research the cause of death on as many dogs in the pedigree *and their siblings* as possible, and as often as possible to breed to older males who have already reached the average age. This means that it is unlikely that we will breed to today's top-winning dogs but we might be breeding to their sires if their pedigrees meet our other criteria.
We are also committed to raising our dogs with as few chemicals as possible while still maintaining their health. We feed Bravo Raw Diet, a raw, natural diet based on human-grade materials at a minimum, certified organic if possible. We supplement our dogs with ProBalance, salmon oil, Animal Essentials and Dynamite products. We also no longer vaccinate our dogs regularly, choosing instead to check their immune status with blood titers using Cornell University's VAX-test program. Our vaccination program includes keeping puppies longer (8-9 weeks) so their first vaccine is given to a relatively mature immune system. We encourage our buyers to follow this program, as well. We have also added cancer to our warranty, offering a 6-year warranty against all fatal cancers.
Out of the 200 dogs we have produced, we have lost seven to what we label early cancer, cancer before 9 years of age. Of those, three came from our Lunar litter so we are not breeding any dogs in or descendents from that litter. We also recognize that as the bulk of our puppies continue to age, this number is likely to go up. We continue to study this issue to keep our early losses as low as possible but recognize that we simply cannot avoid this scourge that has attacked our breed. There simply are no guarantees in goldens at the moment and all golden buyers and owners must accept that cancer is more likely than not to strike their dog.
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 and seek to avoid those with a family history of idiopathic epilepsy. There is presently no registry or certification for epilepsy-free dogs.
We have produced three dogs with seizures over the years, all of which were attributed to environmental sources. Two had seizures when exposed to acepromazine, a pre-anesthetic, when being neutered. One of these dogs died and one recovered and has never had another seizure. A third dog had seizures in response to pesticides and stopped seizing when the lawn treatment company was changed. He has never had another seizure since he was 4.
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.
More 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 ensure we are producing high percentages of cleared dogs and seek only to breed to dogs with similarly disease-free pedigrees and production rates.
Our breeding methods have been effective in accomplishing two goals: reducing our overall rate of dysplasia in our dogs AND, as importantly, reducing the symptoms experienced by those dogs we breed that are dysplastic. As of 2010, over 92% of the dogs that we have produced have normal hip conformation with 11.5% receiving Excellent ratings. Of the 8% of dysplastic dogs that we produce, most have no symptoms throughout their lifetime; the disease was discovered at their two-year screenings and was never evident again.
Inherited Heart Disease. Heart disease is prevalent in goldens although not as bad as many other breeds. The breed's primary heart problem is Subarterial Aortic Stenosis (SAS) but goldens also face Mitral Valve Dysplasia and other valve problems.
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 all genetic heart disease by a cardiologist. You can find a list of board-certified veterinary cardiologists at http://www.vetheart.com/bystate.htm.
The OFA has a heart registry so some breeders may provide you with OFA certification. These numbers will look like GR-CA2544/31F/C-T indicating the dog was a golden retriever (GR) who got the 2544th cardiac (CA) clearance when the dog was 31 months old (31). She is a bitch (F) and the clearance was done by a board-certified cardiologist (C). Other veterinians you might see listed are S for specialist and and P for practioner. Finally, the -T at the end indicates the dog is tatooed. This is being changed to PI for permanent identification.
Over 97% of Gaylan's dogs have clear hearts, though some do have athletic hearts that require Doppler examination for clearance. Of those that failed, one was equivocal, two had mitral valve abnormalities, one had tricuspid valve abnormalities and one was diagnosed with SAS.
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. In addition, the screening methods are still developing. All Gaylan's brood bitches will be screened at or after 2 years of age 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 grades in the number, e.g. GR-EL1121.
Over 97% of Gaylan's goldens have normal elbow conformation. We have produced five dogs with Grade 1 elbow dysplasia and one with Grade 3. This latter dog required surgical correction of his ED.
Pigmentary Uveitis. Recently, pigmentary uveitis (PU) has been found to affect golden retrievers, including some of ours. This progressive disease of the eye is not due to infection or systemic disease, but appears to be a hereditary, immune-mediated disorder. Researchers and ophthalmologists know little about this disease's cause, progression or treatments. This disorder affects older dogs (the average age of onset is 8 years old) of both sexes and is usually a bilateral condition.
Although 90% of our dogs have normal or "breeder option" CERF exams throughout their lifetimes, we now have eight dogs affected by pigmentary uveitis, one of which is severely affected. This has caused us to increase the focus we put on this disease in our breeding program. We are attempting to avoid doubling up on PU in pedigrees to reduce the risk of affected dogs. We are participating in Purdue University's Dr Wendy Townsend's research on PU in hopes of them developing a DNA test for this disease over the next few years. Once this test is developed, we will test all of our breeding stock.
Of all of the diseases goldens are facing today, this is the one that presents the greatest risk to Gaylan's dogs. We highly encourage all of our owners get their dogs' eyes examined by an expert veterinarian every year FOR THEIR LIFETIME. We encourage buyers of ANY American golden retriever to educate themselves about this disease, since most goldens appear to be at risk. The disease is cropping up primarily in conformation lines but has also been seen in field dogs. If you are going to buy an American golden, you must accept that PU is a possibility over your dog's lifetime.
Although we are trying to breed away from PU, none of us know enough about this disease to do so with total confidence.
prcd-PRA. In addition, goldens may suffer from a few forms of progressive retinal atrophy (PRA). This disease has been thought to be relatively rare in goldens, affecting only a few families. However, in 2007 a number of goldens from relatively mainstream families were identified as either affected or as carriers of prcd-PRA. Luckily, the golden retriever form of this disease can be identified using a DNA test developed by Optigen. While the golden retriever community assesses the impact of this disease, we have chosen to test all of our breeding stock who are not clear by parentage (the result of a breeding of two Optigen Normal parents). We have posted the results on www.k9data.com and have enrolled our dogs on the new website for golden retriever DNA testing www.goldendna.com.
Since prcd-PRA has been shown to be a simple recessive trait, we test our breeding stock, breeding according to the Optigen guidelines (clear to clear or clear to carrier). We will provide the results of the DNA test to our buyers and, if we breed to a carrier, will test the puppies before they go home. Thus far, we have not produced any PRA-affected dogs.
Here is some info about prcd-PRA from the Optigen website:
The genetic disorder, prcd-PRA, causes cells in the retina at the back of the eye to degenerate and die, even though the cells seem to develop normally early in life. The “rod” cells operate in low light levels and are the first to lose normal function. Night blindness results. Then the “cone” cells gradually lose their normal function in full light situations. Most affected dogs will eventually be blind. Typically, the clinical disease is recognized first in early adolescence or early adulthood. Since age at onset of disease varies among breeds, you should read specific information for your dog. Diagnosis of retinal disease can be difficult. Conditions that seem to be prcd-PRA might instead be another disease and might not be inherited. OptiGen’s genetic test assists in making the diagnosis. It’s important to remember that not all retinal disease is PRA and not all PRA is the prcd form of PRA. Annual eye exams by a veterinary ophthalmologist will build a history of eye health that will help to diagnose disease.There are also other forms of PRA that affect goldens but these forms are still very rare and have not shown up in the lines that we breed to.
Unfortunately, at this time there is no treatment or cure for PRA. If your dog is affected, you may find it helpful to read about other owners’ experiences living with blind dogs. (suggested links:www.eyevet.org and www.blinddogs.com)
Swallowing Disorders. In the last decade, some families of golden retrievers have experienced swallowing disorders that range from very mild to life-threatening. We are just learning about this disease and our intention is to avoid any dog who has or produced a swallowing disorder or who has siblings or parents with it. At this point, we have not produced any dogs with swallowing disorders. As we learn more, we will revise this section.
Allergies, Hot Spots, Skin Problems. We do not accept that allergies and hot spots are normal for a golden retriever. We seek lines that are allergy-free and that have hot spots only rarely, if ever. We also do not breed for an over-abundance of coat that may be the underlying cause of hot spots. We seek to breed only dogs that do not have chronic skin problems, itching or ear infections, as well as those that do not require constant bathing or grooming to maintain their health. We do not believe golden retrievers should have to be blown dry every time they swim.
A few dogs in a few of our litters have some skin allergies but they are in the minority and we will not breed any of these dogs.
Immune-related Problems. Goldens are increasingly falling prey to immune and autoimmune diseases, such as lupus and masticatory myositis. We maintain a husbandry program that has as its goal the strongest immune systems that we can produce in our dogs. We also seek to only breed dogs that have no chronic immune-related problems and have produced one dog with lupus and none with masticatory myositis.
Part II.This portion lists additional genetic diseases that affect goldens and for which we screen, if possible. However, these diseases are a lower priority for us since they do not debilitate affected dogs or are easily treatable.
Eye Problems. The most common eye problems of golden retrievers are bilateral, juvenile-onset cataracts, retinal dysplasia 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. We have produced four dogs with juvenile cataracts but none whose sight was affected. We have not yet used an affected dog for breeding but do not rule it out given the minor form this disease takes in goldens. Optigen is very close to having a DNA test for this form of cataracts and we look forward to using it to identify our breeding stocks' genetic status when it becomes available.
In addition, goldens may suffer from retinal dysplasia (RD). We have produced three dogs with retinal dysplasia, though none are seriously affected. Mild forms of RD are only visible very early in the dog's life, disappearing by 3 or 4 months of age. Thus, we screen all of our litters at 8 weeks. We will breed puppies with retinal folds that resolve by 2 years of age but we will not breed dogs diagnosed with retinal dysplasia any time in their lives.
Eyelid abnormalities in goldens include an inward rolling of the eyelid (entropion, ectropion) and the existence of extra eyelashes on the inside of the eyelid (distichiasis, trichiasis). We also do not breed dogs with entropion, ectropion or other serious eyelid disorder. We have produced a number of dogs with a few distichia so we note but do not base breeding decisions on this abnormality.
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.
Thyroid Abnormalities. Goldens are increasingly affected by autoimmune 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 have found thyroid testing to be inconclusive so test only those dogs who show symptoms of thyroid abnormalities. Thyroid testing is done at a number of laboratories across the United States The most common ones you will see are from Cornell and the University of Michigan. The OFA now provides a registry for thyroid screening. The OFA number will look like GR-TH226/24F-PI, indicating the dog is the 226th golden retriever (GR) to register for thyroid (TH). The dog was 24 months old (24) when the test was done and it was a bitch (F). The PI at the end indicates that this dog is permanently identified with a tatoo, microchip or other feature.
Shoulder Osteochondritis Dessicans. Osteochondritis dessicans (OCD) is a developmental disease of joint cartilage that can occur in the elbow (see Elbow Dysplasia section above), shoulder and hock in golden retrievers. Researchers do not know if OCD is inherited. We do not breed dogs with OCD, regardless of whether it required surgical treatment, and avoid lines with numbers of affected dogs. Thus far, we have produced three dogs with OCD, two littermates in the 1980s and one more recent.
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. We no longer screen our breeding stock although will avoid breeding dogs who have been diagnosed with the disease. Only a few U.S. labs provide vWD screening. We do not routinely test for vWD and have produced no dogs with this disease.
Other Genetic Problems. Goldens are affected by other diseases with undetermined or poorly investigated genetic bases. These include panosteitis, cryptorchidism, missing teeth, white or black spots, and poor bites. In their mild form, none of these issues are serious enough for us to do more than monitor in our breeding program. If you have specific questions about our production rate for these issues, we can discuss them via email.
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.
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