Breeders, scientists work to protect dogs

Advances in combating diseases, injuries


The 21st Century dawned with an explosion of scientific knowledge about causes and cures for diseases and injuries in humans and animals. In many cases, research in one species proved of tremendous benefit to other species and provided shortcuts to treatments for pets and people.

The biggest breakthroughs came with the mapping of the human and canine genetic codes. Scientists working to sort out hundreds of thousands of genes found that some sequences on canine chromosomes are similar to some sequences on human chromosomes and can therefore lead to the discovery of markers for some diseases or abnormalities in both species.


Breeders make the difference

The attention paid to canine well-being by breeders and other fanciers has focused millions of dollars on research into canine medicine. Breeders make their impact by providing pedigrees and genetic material for various studies and by voting to send dollar donations from their kennel clubs and specialty clubs. The result is an army of support in dollars and dogs for the frontline scientists who write the grants and labor in the trenches.

The outcome? Advances in identification, treatment, and prevention of diseases that affect single breeds, multiple breeds, and all dogs. For example, research in copper toxicosis helped breeders of Bedlington Terriers to weed out carriers of this disease in their breed; investigations into the genetic marker for epilepsy helped Belgian Tervurens, Belgian Sheepdogs, and about two dozen other breeds; and studies of hip dysplasia conducted in large-breed dogs resulted in preventive measures, information, surgeries, and treatment protocols that benefit all dogs.

Breeders donate dollars to this effort through the nonprofit AKC Canine Health Foundation(1), Morris Animal Foundation(2), American Veterinary Medical Foundation(3), and the Orthopedic Foundation for Animals(4), and through health funds managed by the breed clubs themselves. They donate genetic material by swabbing the inside of a dog's cheek or drawing blood and occasionally do test breedings to help determine mode of inheritance for some diseases. What goes around comes back around; when the studies are complete and screening tests become available, breeders complete the circle by screening dogs for diseases, enrolling dogs in health registries, and planning breedings based on health profiles.


Canine health registries

Canine health registries provide breeders with a nation-wide data base to help determine the health of an individual dog, assess the health trends in the breed, and assist in making breeding decisions.

Open registries report on every dog they test. Closed registries report only on dogs that pass the screening.

Founded in 1966 to help quantify the incidence of hip dysplasia and help breeders reduce its manifestation, the Orthopedic Foundation for Animals(5) reads radiographs (x-rays) and catalogs information about hip and elbow dysplasia (joint malformations), thyroid disease, congenital cardiac disease, and patellar luxation (loose kneecaps), and offers DNA testing for several diseases, including copper toxicosis, progressive retinal atrophy (an eye disease), Von Willebrand disease (a bleeding disorder) and renal dysplasia (a kidney abnormality).

A semi-open registry, OFA reports the results of all dogs that pass the screening tests and lists dogs that fail the tests only if the owner agrees.

Any veterinarian can do the joint radiographs for OFA reading, but many breeders prefer to use an orthopedic specialist for this purpose. OFA costs range from $15 for sebaceous adenitis tests to $40 for combined readings of hip and elbow radiographs and do not include the veterinary fee for taking the radiographs. All submitted radiographs and DNA samples must include the dog's DNA identification profile or microchip or tattoo number.

Puppy buyers can use the OFA statistics to build information about the breeds under consideration. The statistics are catalogued on the website (http://www.offa.org/stats.html) in two ways, by breed and by ranking among breeds that have been tested for each abnormality. Those who have chosen a breed and are looking at puppies from a particular litter can research the sire and dam of the litter by proving the name and breed in the form at http://www.offa.org/search.html.

The Canine Eye Registry Foundation is both a registry for dogs that are clear of known heritable eye disease and a research data base to help track the incidence of disease in a particular breed. The eye examinations are good for 12 months; the dogs must be permanently identified by microchip or tattoo.

CERF examinations are done by veterinarians who are diplomates of the American College of Veterinary Ophthalmologists. Fee for the exam varies with the clinic; cost of registering the dog with CERF is $10.50 for the initial enrollment and $8 for annual updates.

Developed at the University of Pennsylvania, PennHIP (Pennsylvania Hip Improvement Program) is a multi-faceted approach to diagnosis of hip dysplasia. Unlike the single-radiograph method used by OFA, PennHIP uses three radiographs to determine whether the dog has loose hips that predispose it to changes leading to osteoarthritis. PennHIP radiographs are submitted to both PennHIP and OFA. Veterinarians must be certified in the PennHIP method in order to x-ray dogs for its database. A list of certified veterinarians is available at http://www.pennhip.org/.


Planning breedings

It is easy to see that breeders face some serious decisions when planning to produce a litter. No longer is it fine to put one nice-looking dog together with another: ethical breeders and educated buyers want healthy dogs that do not carry or manifest genetic diseases that can be controlled by careful selection.

While there is no way to guarantee that puppies will be healthy, the owner of a female dog may conduct a nation-wide search for a male that is not only a good example of its breed, but also complements the female's physical traits and is free of those diseases for which screening tests are available.

Screening tests for breeding stock raise the cost of producing a litter and therefore figure in the prices for the puppies. Cost of hip x-rays (the most commonly-used screening test) varies according to the veterinarian who does the radiographs and the registry used. The total can be $250 or more, especially if the cost of permanent identification (DNA profile, tattoo, or microchip) is included. If the radiographs show hip abnormalities, the breeder must start over with a new dog.

If the breed is also susceptible to elbow dysplasia, slipping kneecaps, von Willebrand's disease, eye abnormalities, or other diseases that can be detected by screening tests, the costs obviously multiply before the breeding can be done.


Searching for a puppy

People searching for a puppy of a particular breed want a dog that is recognizable as that breed and is healthy. Although there are no guarantees, chances of getting a healthy puppy that looks like its breed are far greater when dealing with a breeder who takes advantage of the explosion in canine health research. Many responsible breeders are members of kennel or breed clubs and are listed in regional breeder directories. AKC also maintains a list of breed club contacts for information about its breeds and varieties on the AKC website at www.akc.org.

Dog shows are also a good place to meet responsible breeders. A list of local events is available on the AKC website at www.akc.org.

A prospective buyer should have a list of questions to ask to help determine whether a breeder is concerned about puppy health. Tops on the list should be "Is your breeding stock screened for hip dysplasia and eye problems?" followed by "Can I see the certification?" If a breeder says no, if he claims that hip dysplasia is not a problem in his breed, or if he alleges that breeders who screen for these abnormalities do so only so they can increase the cost of their puppies, a buyer should walk away.

Prospective buyers should also research the breed before approaching a breeder so they can ask breed-specific health questions. For example, poorly-bred Dalmatians can be unilaterally or bi-laterally deaf; Newfoundlands can have heart problems; Basenjis are susceptible to Fanconi syndrome, a kidney disease; Akitas and Poodles are among a handful of breeds susceptible to sebaceous adenitis, a skin disease; Collies may have Collie eye anomaly; toy breeds are susceptible to patellar luxation (slipping kneecaps); and some breeds have a higher frequency of particular types of cancer. [More on finding a responsible breeder]


Conclusion

The phrases "genetic disease" and "inherited defect" should not strike fear into the hearts of pet owners. Many heritable diseases or abnormalities are neither fatal nor debilitating. Hip dysplasia, probably the most common and certainly the most notorious genetic problem, can be mild, moderate, or severe and may generate few problems as the pet learns to compensate for his limitations. Severe hip dysplasia can be repaired by surgery, and the development of arthritis can sometimes be slowed with nutritional supplements such as glucosamine and chondroitin. However, a dysplastic dog should not be used for breeding or strenuous sport such as agility, hunting, sledding, lure coursing, or herding.

Underactive thyroid, another abnormality gaining in notice, can be easily controlled with low-cost medication, but dogs with very low thyroid values should not be bred.

When looking for a puppy, remember that all dogs (like all other animals and plants) carry genetic defects, that not all genetic defects cause painful disorders that require Herculean efforts to cure or control, and that chances of getting a pup with fewer serious defects are enhanced if you buy from a responsible breeder who uses the tools scientists have provided.

Notes

1. Founded in 1995, the American Kennel Club Canine Health Foundation is the new kid on the block. However, in five years, it has jump-started canine health research by providing breeders and clubs with an effective way to benefit the health of the dogs they love. AKC has donated more than $10 million to CHF since it created the health organization, and CHF has raised millions more through memberships, fundraisers, project donations, and bequests. The foundation surveys breed clubs to find out which diseases are considered most serious, considers grant proposals from scientists working at universities and veterinary colleges for funding each year and reports on the progress made, and hosts annual education meetings to acquaint breeders and breed clubs with the progress made in various areas.

2. The Morris Animal Foundation, the granddaddy of animal health organizations, has been funding research into animal diseases and nutrition since 1948. This foundation has awarded more than $21 million in grants, including $2.4 million for 2001, for studies to benefit dogs, cats, horses, and wildlife.

3. The American Veterinary Medical Foundation includes animal health research as one of three areas it covers. Established in 1943, AVMF has a low profile among dog owners.

4. OFA is a founder of the AKC CHF and also directly funds canine research. The Morris Animal Foundation provides grants through the CHF as well as accepting applications and funding projects on its own.

5. Until recently, OFA reported only those dogs that passed the screening tests. The policy has changed to allow dog owners to specify whether they want failing dogs to be listed as well.

Norma Bennett Woolf

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