Page 26 - Chow LIfe - Spring 2020

Propranolol makes HSA susceptible to chemothera- German Shepherds and it causes cardiac hypertro-
py. phy (enlargement/weakening), leakage and regurgi-
tation. Again, each breed’s genetic marker is diverse.
Jaime F. Modiano, VMD, PhD presented two de- If left untreated, dogs live around 2 years but with
cades of advances in HSA (the light at the end of the beta blockers 3-5 years. Atrial fibrillation (better
tunnel is getting brighter and it’s not a train). With known as A-Fib) is very inheritable in Irish Wolf-
increased lifespan but without the corresponding hounds (69%) and is an autosomal dominant (any
evolutionary improvement, cancer has increased non-sex gene). Dilated cardiomyopathy (enlarged
by 25%. While breed predilection has been noticed, heart) is prevalent in Dobermans and large breeds
HSA can occur in any breed. They now believe HSA in general. There is a genetic component (PDK4,
derives from cells related to bone marrow nurse cells R9H, TTN Titin) as well as a nutritional component.
(i.e. cells that feed and assist other cells), which sup- Viagra works well for the pulmonary hypertension
port the formation of blood cells and blood vessels. associated with this disease. The OFA Cardiac data-
The signaling pathways that govern HSA cell behav- base is useful for tracking this disease.
ior promote many of the biological processes as-
sociated with the disease but there has been limited Jerold S. Bell, DVM presented his paper titled, “Dog
success using these signaling pathways for preven- Breeds as Populations” which appears later in this
tion. A drug developed by Dr. Modiano’s lab, which issue of Chow Life. He noted that allergies, hip
they call eBat has been shown to create an inhospi- dysplasia, cataracts, cancers, cruciate ligament/slip-
table microenvironment for tumors and eliminates ping patellas and cardiac issues are ancient diseases
sarcoma stem cells. throughout the entire gene pool of all breeds. Breed-
ing selection becomes too limited when too many
Jerold S. Bell, DVM led a genetic panel of veterinari- dogs are eliminated from the breeding pool for
ans to discuss practical insights on breeding. Genetic too many different reasons and with small popula-
testing should not eliminate a good dog from the tion breeds, proper selection is critical. Breed away
breeding pool but rather help manage breeding deci- from extreme phenotype because if causes diseases
sions, i.e. the tools should not become the goal. A and avoid the popular sire effect. If we don’t breed
critical point related to Chows was that many breeds for health we won't get it. Since outcrossing doesn’t
and dogs are homozygous for Degenerative Myelop- change the frequency of deleterious genes, a mixture
athy (similar to ALS) but only seven breeds actually of line breeding and outcrossing is recommended.
manifest symptoms, so there has to be other genes Don’t line breed on a dog beyond the 5th generation.
in play. This scientifically confirms that CCCI does Review the CHIC standards and database for a mate
not need to include DM testing in the Chow’s CHIC that matches your current breeding requirement and
requirement. The session ended with the cliché, “if performing genetic screening “or” phenotype testing
it’s not a problem, don’t make it one”.
is a must, depending on the availability of tests. It is
On Sunday the sessions were mostly on genetics and recommended that different breeders within a breed
breeding. select for different sports (i.e. conformation, obedi-
ence, rally, etc.) for breed diversity.
Brenda Bonnett, DVM, PhD discussed an online
database resource by the International Partnership Finally, Leigh Anne Clark, PhD presented Utiliza-
For Dogs (IPFD) to help with the “Harmonization tion of Genetic Risk Assessment for a Multifactorial
of Genetic Testing for Dogs (HFTD) as well as Breed Disease. This was a technical presentation, tailored
Specific Resources”. It is designed to assist the dog towards geneticists in the audience and concentrated
world with new genetic testing developments, to on a study done for Dermatomyositis’ genetic iden-
evaluate and prioritize recommendations, determine tification. This is a skin disease affecting Collies and
the best labs, standardization of lab’s tests and termi- Shetland Sheepdogs, where blood vessels manifest
nology and consideration of other conditions in the themselves as skin lesions. She said 65% of diseases
breed separate from genetic testing. The HFTD data- are autosomal recessive. For Dermatomyositis to
base (DogWellNet.com) assists with determining the manifest itself, one out of three particular chromo-
quality of labs who have shared details about their somes has to be homozygous. Merles rarely develop
quality of testing. The Health Strategies Database for Dermatomyositis and an environmental trigger is
Dogs (HSDD) includes tests recommended by breed needed.
clubs and is searchable by information source, breed, Last year the CHF set a goal to focus their grants on
condition or country.
genetic research. Their objective is for genetics to
Joshua A. Stern, DVM, PhD, DACVIM (Cardiol- make diagnoses earlier, improve and expand testing,
ogy) presented Cardiac Diseases of Purebred Dogs, create new treatments and/or cures. It appears to be
Genetics and Beyond. Subvalvular aortic stenosis succeeding.
(narrowing) in the left ventricle is prevalent in Bull
Mastiffs, Newfoundlands, Boxers, Goldens and
Rottweilers with each breed’s genetic marker on a
different chromosome. Beta blockers should be used
to reduce arrhythmias. Pulmonic stenosis in
the right ventricle is prevalent in Bulldogs,
French Bulldogs, Pit Bulls, Chihuahuas and
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