ATTENTION ALL KUVASZ BREEDERS AND OWNERS!

 IMPORTANT HEALTH NEWS ! GENETIC PRA TESTING FOR KUVASZ!!!!

Some of you may or may not be aware, there is a health threat lurking in our breed: it is called Progressive Retinal Atrophy (PRA). PRA is a genetic, inherited condition of the retina (the "film" in the camera), which can eventually lead to blindness. The severity of this problem became apparent in Europe, where as of 2007, more than 50% of all Kuvasz evaluated for the PRA mutant gene (carriers + affected combined) have been identified. Out of this 50% population, approximately 10% of the Kuvasz tested were classified as ‘Affected’ (see below regarding ‘Affected’).

The good news is that PRA does not result in death. The better news is that there is a simple genetic test that can be performed to determine your dog’s genetic PRA status. Below are some common questions regarding PRA and answers to those questions.

Q: What exactly is Progressive Retinal Atrophy (PRA)?

A: PRA is a genetically inherited disease that causes the retina of the eye to degenerate slowly over time. The form of PRA that afflicts the Kuvasz is prcd-PRA; prcd is an acronym for progressive rod-cone degeneration. Rods and cones are cells in the retina whose functions are to provide vision in low light levels and full light conditions respectively. Per OptiGen: “In the case of PRA, also keep in mind that not all reginal disease is PRA and not all PRA is the form currently detectable in your breed. Accurate diagnosis is essential. A dog can test as normal or carrier, yet be affected by a different type of PRA. Although more than one type of retinal degeneration probably occurs in every breed, by far the most common type of PRA for your breed is the type current beingly tested by OptiGen.”

Q: How does a dog become afflicted with prcd-PRA and eventually become blind?

A: Generally speaking, in order for any gene to be active, there needs to be 2 copies present. Because PRA is a recessive trait, blind dogs must have inherited the ‘prcd’ carrier gene from each parent in order to cause blindness in an offspring. This condition is known as an ‘Affected’ dog.

Q: What happens if the dog has one normal gene and one “prcd” carrier gene?

A: Since prcd-PRA is a recessive condition, the normal gene is the dominant gene and the dog will not develop the disease. The dog will be identified as a ‘Carrier”. It is important to understand that a dog with a “carrier” gene is a healthy dog and it will not develop the disease.

Q: As a ‘Carrier’, does that mean that this carrier dog can infect other dogs in the kennel or household?

A: No, it is not like a virus or bacteria that can be communicated and contracted by other animals. To pass along this condition, the gene would need to be propagated. That can only happen through breeding.

Q: Can you breed two dogs that are carriers?

A: It is not recommended, because of the likelihood of producing affected dogs. 

Q: Can PRA carriers ever be bred?

A: Yes, as long as they are bred to dogs that have a non-carrier, or clear status, as confirmed by a DNA marker test with results reported in an open Database (ie OFA, CHIC). (See questions on DNA Marker test by Optigen below). If carriers are bred and their carrier status is not reported in an open Database, unsuspecting breeders in the future could be in the same position that we find ourselves now. Only by having accurate information on carriers and affected dogs can we truly impact the future of the breed for everyone.

Breeding carriers to non-carriers will NOT produce "affected" dogs who have the potential to go blind from prcd-PRA. The only time prcd-PRA blindness can occur is if two carriers are bred together. A carrier bred to a non-carrier will produce all offspring who will NEVER develop prcd-PRA, though a percentage of the offspring may be carriers themselves.

Q: Can the offspring of carrier-to-non-carrier matings be bred?

A: Yes, certainly, with the proper testing. Breeders will have to perform the OptiGen prcd-PRA marker test on any breeding stock resulting from the carrier-to-clear breeding. If the offspring is clear, it can be bred to any other dog, including a carrier. If the offspring is a carrier, then, like its parent, it should only be bred to a clear dog.

Q: What is the OptiGen prcd-PRA test?

A: The OptiGen prcd-PRA test is a DNA-based test performed by OptiGen, LLC (www.optigen.com ), to test for the prcd form of Progressive Retinal Atrophy (PRA) that has been identified in the Kuvasz. Any other type of prcd-PRA test that is used for other breeds is highly NOT recommended and will most likely not work.

Q: How do I get DNA from my dog?

A: There are 2 ways to get DNA samples from your dog: by drawing blood or by performing a swab of the inside cheek of the dog.

Q: Are there pros and cons for either the blood or swab samples?

A: The advantage of the interior cheek swab is that you can do it yourself at home, and that your dog doesn’t have to be poked with a needle. The disadvantage of the swab is that if it is not performed properly, there could be contamination that would affect the DNA test.

The advantage of the blood sample is that the DNA would be abundant and when isolated, fairly pure. The disadvantage is that unless you are a phlebotomist or vet tech, this procedure would have to be performed at your vet. In addition, your dog would have to be stuck with a needle!

Q: What is the cost to perform the Kuvasz-specific Optigen prcd-PRA test?

A: As of January 14, 2008, Optigen charges $195 US for the test. It is another $15 to report the result to the Orthopedic Foundation for Animals (OFA), a public canine health database. Optigen also offers discount days (refer to www.optigen.com). During these "Discount Days", tests may be ordered with a code that will discount each order by 15%; if the request is entered through the website, it will be discounted an additional 5%. The next Discount Days are set for January 28 through February 8, 2008.  You may enter your request through the Optigen website with the code OGWIN8.

Q: What is the Kuvasz Club of America (KCA) doing to promote the awareness of this disease?

A: In addition to this Q & A information notice, the KCA Health Committee has negotiated a discount for Optigen to automatically report ALL open PRA testing results to OFA. Instead of the $15\dog fee, the fee has been reduced to $7.50\dog. In addition, the KCA is working on providing a rebate to owners to cover the costs of the OFA reporting. Furthermore, the Health Committee is under negotiations to hold an Optigen 20/20 clinic at this year’s National Specialty in Bloomington, IL. This would result in an automatic 20% reduction in the test fee. If the request to test is made on-line, then an additional 5% discount will be applied.

Q: As a breeder, what should I do to make sure that I can help eventually reduce or eliminate prcd-PRA in the Kuvasz?

A: The ultimate purpose of using genetic marker tests is for breeders to eventually replace carrier breeding stock with non-carriers. But if the best, soundest, most typey dog in a litter is a carrier, then it is certainly ethical to keep that dog and breed it, provided that any dog that it is bred to is a non-carrier, as confirmed by the prcd-PRA test. Not using the prcd-PRA test would be unethical and irresponsible.

The breeder who breeds a carrier to a normal dog will not produce the disease in any of the resulting puppies, and may be making this decision to help preserve the long term genetic health of their line and the breed as a whole. In fact, Dr Jerold Bell of Tufts University argues against quickly eliminating animals that are carriers of a genetic disease. There are reports that document that such quick action to cull carrier dogs from the breeding program reduces the genetic diversity of the breed and increases the incidence of other diseases. Breeders utilize genetic tests as one factor in making well informed breeding decisions and puppy buyers can also utilize them to become well educated consumers in their effort to find a healthy new addition to their family. Dogs (and people) are made up of thousands of gene pairs. At this time we only have one genetic test to help us in our common long-term goal for healthy Kuvasz. The use of genetic testing in making breeding decisions is a tool we can use to keep our genetic diversity without producing the disease. As more genetic tests are developed, the use these tests will hopefully help us to eliminate serious diseases, such as cancer, in people and in dogs.

Q: As a puppy buyer\ owner, what should I be looking for when buying a dog from a breeder?

A:  With respect to PRA concerns, the puppy buyer should inquire if the sire and dam have been DNA tested for prcd-PRA by the breeder.  If the litter is a result of a mating between normal \clear and carrier, some of the puppies may be clear and some may be carriers -but none of them will be affected, and as such cannot go blind with PRA. It is important to remember that PRA is only one health issue. In selecting a breeder it is important to evaluate all health testing that a breeder is doing.

The KCA Health Committee strongly encourages OPEN reporting of ALL results of health testing at the following sites:

Orthopedic Foundation For Animals at: www.offa.org

Canine Health Information Center at: www.caninehealthinfo.org

For more information about buying a Kuvasz, see: http://www.kuvasz.com/kuvasz/buying.htm

Q: Lastly, as a pet owner, do I need to test my dog for prcd-PRA?

A: The ultimate purpose of using genetic marker tests is for breeders to make responsible and appropriate breeding decisions. However, even as a non-breeding pet owner whose dog(s) will not reproduce, it may be appropriate for you in certain circumstances to DNA test to determine your dog’s genetic status. But remember, your dog can ONLY go blind from prcd-PRA if it is DNA tested as "Affected". A dog can only have "Affected" status if BOTH of its parents are carriers (see above). Check with your breeder first for their advice before testing- it may be your dog’s parents have already been tested and your breeder might have that information. After all, it is their ethical responsibility to do so. You should also check the OFA database at www.offa.org to see if the parents of your dog are listed in the database for all their health clearances including their PRA status. Companion animals resulting from parents who are either both clear or one clear and one carrier, would not need to be tested unless the owner simply wishes to do so. If you are unable to communicate with your breeder, or cannot find the information in the OFA database www.offa.org, contact the KCA Health Committee (see below) and we’ll attempt to obtain that information for you

For more information on PRA, please contact the KCA Health Committee at health@kuvasz.com

The Kuvasz is essentially a very healthy breed. A normal life expectancy would be more than 10 years with many reaching the age of 14 years.

Because of the breed's rapid growth and large size it is predisposed (prone) to developmental bone problems. Improper nutrition and trauma can contribute to the expression of clinical signs. Osteochondritis dissecans (OCD) is such a disease. OCD is seen most commonly in the shoulder but can also occur in the elbow, hock or stifle joints. With OCD of the shoulder, lameness generally first occurs between 4 and 9 months and may be associated with a fall or accident playing with another dog. Lateral radiographs of the shoulder will reveal a flattening of the humeral head. Since many affected dogs (50%) have OCD in both shoulders, lameness is not always obvious. Bilaterally affected Kuvasz may only have a shortened anterior stride or "lack of reach". Treatment for OCD of the shoulder involves a surgical removal of the cartilage flap. Both shoulders can be operated on at the same time and recovery is rapid. The most common postoperative complication is the formation of a seroma (fluid buildup over the incision site). These are drained and are a short term problem and can be avoided or minimized by strict post-op cage rest.

Mild cases of OCD may respond to conservative treatment if diagnosed early. A series of injections of a drug called Adequan may help in cases which are diagnosed early. However, severe arthritis of the shoulder can occur before the age of two with untreated OCD.

The most common cause of hindleg lameness in the Kuvasz is anterior cruciate ligament injury of the stifle joint (knee). The lameness is usually of sudden onset with a characteristic holding up of the affected leg. The dog may marginally improve and toe touch the leg to the ground. The dog will sit with the affected leg off to the side. The damage to the ligament allows the femur and the tibia to slip when the dog puts his weight on the leg and this causes the characteristic gait. If the ligament is not replaced by surgery, arthritis will occur resulting in permanent lameness or pain.

Cruciate ligament damage is diagnosed by palpation of laxity (looseness) in the stifle joint. However, in dogs with long standing lameness the joint capsule will thicken and prevent the "drawer sign" thus frustrating diagnosis. Radiographs may help in the ruleout of other concurrent problems. A diagnosis of hip dysplasia does not rule out a stifle problem as many dogs with hip dysplasia are asymptomatic (not lame) until they injure their cruciates.

Hip dysplasia is seen in the Kuvasz breed. The more generations of hip dysplasia certified-free dogs in the pedigree the less chance that the offspring will be dysplastic. Breadth of pedigree is as important as depth for selection of breeding stock. A dog from a hip dysplasia-free litter is a better breeding candidate than one who has dysplastic siblings. Most dysplastic dogs have a bilateral hip dysplasia, less than one in five is dysplastic on one side. Dogs have variable clinical signs - some puppies may have severe gait problems between 4 and 6 months. They may have a very difficult time rising and may hop instead of gaiting smoothly. Other dysplastic dogs may have few if any clinical signs until they are geriatric and suffer from arthritis. Because of this, radiography of all breeding dogs is essential - a normal appearing gait does not rule out hip dysplasia.

Occasionally a young dog may have difficulty rising and start to shift weight onto the front legs causing straightening of the stifles and a characteristic "popping" of the hocks.

These dogs may have a normal hip radiograph but have a bilateral cruciate ligament problem. This has been seen in large rapidly growing dogs. Again, if the injured cruciates are not diagnosed in the initial stages, thickening of the stifle joint capsule due to inflammation and arthrosis will prevent the palpation of joint laxity. An exploratory arthrotomy may be necessary for diagnosis in these cases.

Hypertrophic osteodystrophy (H.O.D.) is a metabolic bone disease rarely seen in young Kuvasz. The typical age of onset would be 12-20 weeks. Puppies generally show swollen, painful ends of longbones and may have a fever as well as loss of appetite. If these puppies are not diagnosed early permanent damage may necessitate euthanasia. Research with Great Danes (the breed showing a relatively high incidence of H.O.D.) shows that a high energy, high protein diet or excess supplementation may predispose puppies to H.O.D. Treatment consists of putting the affected animal onto a high quality but more moderate diet as well as using analgesics to encourage the puppy to eat and stay mobile.

Panosteitis ("pano" or growing pains) is rarely seen in the Kuvasz but can cause acute lameness in the immature animals. The affected leg is very sore and the lameness occasionally shifts from leg to leg. The lame puppies generally show a severe pain response to palpation of the area around the blood vessel (nutrient foramen) in the affected longbone. The distal humerus and proximal radius are most commonly involved but panosteitis can affect any longbone in the body. Diagnosis is by palpation and radiography. Treatment is primarily rest and analgesics if necessary.

In summary, it is important that the Kuvasz owner seek experienced veterinary attention when their dog is lame. Diagnosis is quicker in the early stage and if surgical intervention is required the prognosis is better. Surgery on an acute cruciate ligament injury will minimize future arthritis and return the dog more quickly to normal function than on a dog with a long-standing arthritic changes and a grossly thickened joint capsule.

-Dr. Carol Graham, studied at OVC with Dr. Paul Pennock, Canada's foremost authority on skeleton disorders. Dr. Graham and Dr. Pennock have spent many hours assisting breeders and owners of Kuvaszok.

 

 Originally published in the Kuvasz Quarterly, Spring 1995 edition.