1. Familial Subvalvular Aortic Stenosis in the Rottweiler
Kathryn M Meurs, DVM, PhD, ACVIM (Cardiology)
Joshua A Stern, DVM
Veterinary Cardiac Genetics Laboratory
North Carolina State University College of Veterinary Medicine

2. SAS in Rottweilers Devastating disease
Mild forms of disease can go unrecognized
Rottweilers over represented
Appears familial

3. 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

4. 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

5. 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

6. 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 6

7. 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

8. Aortic Velocities ARCH Recommendations
<1.9 m/s normal (clear for breeding)
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)

9. Prognosis for dogs with SAS
Highly variable
No clinical consequences
Sudden Death
Congestive Heart Failure
Potential to pass on more severe form to offspring

10. 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

11. 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

12. 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

13. 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

14. Our Study Enroll affected and normal Rottweilers
Use SNParray to analyze entire genome
Identify regions that are different between normal and affected

15. 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

16. We Are Still Enrolling
Normal or affected Rottweilers of variable lineage
Echocardiography results from cardiologist
3 generation pedigree
Blood sample (3ccs purple top tube)

17. 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

18. 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)