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Familial Subvalvular Aortic Stenosis in the Rottweiler
Kathryn M Meurs, DVM, PhD, ACVIM (Cardiology)Joshua A Stern, DVM
Veterinary Cardiac Genetics LaboratoryNorth Carolina State University College of Veterinary Medicine
SAS in Rottweilers
• Devastating disease
• Mild forms of disease can go unrecognized
• Rottweilers over represented
• Appears familial
Background: Subvalvular Aortic Stenosis
• Commonly reported congenital heart disease
• Characterized by aortic subvalvular ridge
• Most common in large breed dogs
• Familial link demonstrated in Newfoundlands & golden retrievers
Physiologic Consequences of SAS
• Aortic stenosis increases pressure in the left side of the heart
• Left ventricular heart muscle thickens in response to pressure
• Aorta can dilate after the stenosis
Consequences of SAS Continued
• Aortic valve may leak
• Thick heart muscle does not oxygenate well
• The thick muscle with less oxygen can lead to rhythm disturbances
Diagnosis:• Gold Standard – Necropsy
demonstration of subvalvular ridge, ring, band or nodules
• Antemortem test – Echocardiography : elevated
aortic velocities – Auscultation: not specific for
SAS– Angiography: presence of
subvalvular stenosis
Auscultation Screening
• Auscultation screening is a good first step– Dogs that pass are unlikely to have SAS– Dogs that fail may or may not have SAS– Echocardiography can help differentiate dogs with
functional murmurs from those with SAS
Aortic Velocities
• ARCH Recommendations– <1.9 m/s normal (clear for breeding)
– 1.9-2.4 m/s equivocal (breeding assumes a certain risk level)
– > 2.4 affected (breeding not recommended)
*ARCH = ACVIM Registry of Cardiac Health(guidelines established by veterinary cardiologists)
Prognosis for dogs with SAS
• Highly variable– No clinical
consequences– Sudden Death– Congestive Heart
Failure– Potential to pass on
more severe form to offspring
Prognosis
• Based on echocardiographic analysis of severity as Mild
– Typically have normal lifespan– Increased risk of bacterial endocarditis– May produce puppies with disease more severe than
their own
Prognosis
• Based on echocardiographic analysis of severity as Moderate
– Increased risk of sudden death, heart failure– May live normal lifespan– Increased risk of bacterial endocarditis
Prognosis
• Based on echocardiographic analysis of severity as Severe
– High risk of sudden death, heart failure– Few live normal lifespan (19-45 months)– Increased risk of bacterial endocarditis
Breeding Considerations
• SAS appears familial in Rottweiler
• Removing dogs from breeding pool should be done with caution– Small gene pool– Equivocal category is
still uncertain– Aortic velocity is not a
static measure
Our Study
• Enroll affected and normal Rottweilers
• Use SNParray to analyze entire genome
• Identify regions that are different between normal and affected
Our Study Continued
• Focus search in regions of interest for a mutation
• Identification of a mutation or mutations that cause SAS (a potential screening tool)
• Participation is confidential
We Are Still Enrolling
• Normal or affected Rottweilers of variable lineage
• Echocardiography results from cardiologist
• 3 generation pedigree
• Blood sample (3ccs purple top tube)
Conclusion
• SAS is a life threatening disease
• Appears to be inherited in the Rottweiler
• Pattern of inheritance is still unclear
• Screening is important in reducing prevalence
• Genetic studies are underway to identify possible mutations
Contact Us
Kathryn M Meurs DVM, PhD, ACVIM (Cardiology)
Joshua A Stern, DVM
North Caroline State University College of Veterinary Medicine
Veterinary Cardiac Genetics Laboratory
Research Bldg. 460
1060 William Moore Dr
Raleigh, NC 27607
(919) 513.8279
www.cvm.ncsu.edu/vhc/csds/vcgl/