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WSVA7-0466
DSAVA: HEALTHY BREEDING
GENETIC COUNSELLING BY PRACTICING VETERINARIANS
J. Bell1
1Cummings School of Veterinary Medicine at Tufts University, Dept. of Clinical Sciences, North Grafton. MA, USA
GENETIC COUNSELING BY PRACTICING VETERINARIANS
Jerold S Bell DVM
Cummings School of Veterinary Medicine at Tufts University, USA jerold.bell@tufts.edu
As practicing veterinarians we see genetic disease in our patients every day. The hallmark of genetic disease is
its predictability, and therefore we have the opportunity to intervene and lessen its impact for our patients. The predisposition to genetic disease is life-long. Therefore these must be treated as chronic diseases and not just with intermittent treatment during clinical episodes. The opportunity to genetically counsel our clients occurs throughout the pet’s life.
On a Client Acquiring a New Pet
If a client asks about adopting or purchasing a new dog or cat, we can discuss breed or mixed-breed phenotypic and behavioral expectations and whether they fit with the client’s lifestyle and home environment. Terrier and terrier-type dogs have very different behavioral characteristics than retrievers or shepherds. Long-haired versus short-haired cats and dogs have different grooming requirements.
If the client is purchasing a purebred dog or pedigreed cat, there are breed-specific pre-breeding health screening requirements for the parents. For dogs these can be found at the OFA Canine Health Information Center (http://www.ofa.org/breedtests.html). Common genetic disorders and tests for cat breeds can be found on the International Cat Care website (https://icatcare. org/advice/cat-breeds).
The WSAVA Canine and Feline Hereditary Disease (DNA) Test website, hosted by the University of Pennsylvania contains information on all DNA tests available in
dogs and cats. You can search by breed, disease, or laboratory. It contains links to the original published article on each disease test, as well as which laboratories run the tests: (http://research.vet.upenn.edu/WSAVA- LabSearch). This site lists all identified mutations, including rare mutations that may not be present in breeding populations.
Health-conscious breeders are happy to provide official
documentation of the results of health screening. In the US, the results of a puppy’s parents’ health screening can be looked up on the OFA website (www.ofa.org). Many other countries have searchable health testing databases; though there are more for dogs than cats.
Some breeds and mixed-breeds (designer or “bred-for- rescue” dogs) do not have specific pre-breeding health screening requirements. All parents of purposefully-bred litters should have pre-breeding health examinations (musculoskeletal, heart, eye, etc.) and history taken
for hereditary disease (allergies, seizures, etc.) to determine their suitability for breeding. Pre-breeding health evaluations should become as routine and commonplace as equine pre-purchase examinations.
In most instances, veterinarians will not be asked for advice by a client prior to a purchase or adoption. When being presented with a new purposefully-bred puppy or kitten for examination, the owner should be told to bring all paperwork provided by the breeder, pet store, broker or agent. If evidence of health screening on the parents has not been provided, health test results on the parents may be looked up in on-line health testing databases.
If health screening results are not available, you can print out the pre-breeding health screening requirements or testable diseases and have the owner ask the breeder for health testing information on the parents. This may be the only way to educate the owner AND breeder
on the ethical obligation of health screening and health conscious breeding. Selective pressure is the only way to reduce the frequency of genetic disorders in purposely- bred dogs and cats. Health screened parents produce healthier kittens and puppies.
Genetic Counseling in Owned Animals
Veterinarians should be knowledgeable about common disorders with genetic tests, and in what patients they should be run. If parental documentation of genetic testing is not available, certain breeds should undergo genetic testing early in life. For example, patients from breeds with an incidence of von Willebrand’s disease should be tested so that measures can be taken to prevent excessive hemorrhage during surgery or injury. Patients at risk of carrying the mdr-1 mutation should
be tested before drug treatment. We counsel owners of large-breed puppies to feed lower calorie “large breed growth or puppy” foods to provide for a more uniform growth rate and better joint development. Boxers should be tested while young for the dominant arrhythmogenic right ventricular cardiomyopathy (ARVC) gene. Carriers can be monitored for arrhythmias through life, and when they occur can be put on antiarrhythmic drugs to prevent heart failure.
An Urban Experience
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