Sub-aortic stenosis(SAS) What do we know about this heart ailment in labradors? As to is it more prevalent possibly than we think? The newfoundland deals with it quite readily. One parent would have to be affected for an offspring to be so.
With SAS do you feel this is a condition that you don't just check hearts and clear them one time?
Anyone with knowledge on SAS please post in. I've learned of yet another SAS affected labrador. Both parents were cleared for TVD screening through echo doppler. If they had SAS that would've been revealed. Unless one of them acquired it later and after their echo doppler to be cleared for TVD.
I've heard of it mostly in Goldens and Boxers, but SAS can appear in any breed and in people.The mode of inheritance is not really known, overall. The website link below indicates that, in dogs, a seemingly clear set of parents could have modifiers or modifying genes that mask the presence of the gene, in both people and dogs. A more recent (2010) reference on Goldens really had nothing new to say.
"The absence of affected parents in such cases could be due to incomplete penetrance. Locus heterogeneity and polygenic inheritance cannot be ruled out based on these data. A complex pathologic basis with a strong role of environment (hemodynamic factors) has also been proposed. The fact that 70% of cases had been given diagnoses by the age of 10 years favors a stronger genetic basis. Almost equal proportions of affected male and female patients make X-linked inheritance unlikely. Most reported pedigrees could fit into autosomal dominant or recessive inheritance with variable and incomplete penetrance. Inheritance of DSS in dogs suggests either polygenic or autosomal dominant inheritance with modifiers."
Yesterday, I received my Purina Today's Breeder magazine and there is an article on SAS. It mostly discusses diagnosis and treatment, but does speak about some genetics in Goldens, Newfies and Rotties. You mighy want to look at it.
Julia
