Canine subvalvular aortic stenosis (SAS) is an abnormal, congenital heart murmur caused by subaortic stenosis (SAS). There is a high incidence of this condition among Rottweilers.
There is also very good evidence that it is also heritable, passed on from generation to generation genetically. This genetic trait is what is called polygenic, so that the inheritance is complex. An animal might have the genes for SAS, yet have no actual sign of SAS. Also, an animal might have signs of Subaortic stenosis, and yet offspring with signs of SAS may not be seen for a couple of generations. Any animal that has Subaortic stenosis should not be bred, because they can definitely pass the defect on to future offspring. There is some controversy as to whether the parents of an animal with SAS should be bred again.
Heart murmurs are graded on a scale of 1 to 6, with one being very mild and six being very serious, with some animals passing away before they reach this high end due to a sudden leap in the grade or through long-termed slowing down. Murmurs can exist due to a large number of heart problems ( infection, trauma, anemia, etc.) and some murmurs are innocent, meaning that no cardiac pathology exists. Tests such as chest X-rays, echocardiography, and electro-cardiography can be performed to evaluate the severity of the situation
Aortic stenosis in the Rottweiler appears to be true subvalvular aortic stenosis (SAS) (similar to that in the Newfoundland dog) as opposed to the valvular form (seen more in boxer dogs) or the supravalvular form sometimes seen in people.
The condition is usually detected during puppy visits to the veterinarian by hearing a heart murmur during physical examination. A heart murmur is the abnormal sound of blood rushing through one of the heart valves. Instead of just the heart beat, a whistle of blood flow through a narrowed opening is heard. The puppy will most likely appear normal in all other respects. There is a possibility that the murmur may come and go, or it may develop slowly; therefore, it is important to have a veterinarian check a puppy's heart often during the first few months of age. This is a very frustrating condition to be identified in your pet because the future is bleak and the chance for long term survival is low.
Puppies and dogs diagnosed with Subaortic stenosis can suffer from heart failure and sudden death. If your dog with SAS develops heart failure, medications can be prescribed to alleviate the clinical signs (sudden/strong lethargicism, heavy panting continuously, rise in temperature etc.) it is experiencing.
The OFA has established a Congenital Heart Registry whose guidelines were established by veterinary cardiologists. A dog at 12 months of age, which auscultates normally is considered to be free of congenital heart disease Upon confirmation of this, the OFA will issue a certificate.
http://rottweilerhealth.org/rott_healthissues.html
http://rottweilerhealth.org/pdfs/grant2620_SAS_findings.pdf
http://www.adoptagolden.com/k9stuff/vetcorner/stenosis.htm
http://www.rottclub.ca/subarotic.html