I realize this is an incredibly old post, hoping you can answer regardless. We're actually testing my purebred golden for the MDR1 mutation as well as he's reacted to several of the drugs they list. Did your golden come back with the mutation? I can't seem to find any research that would indicate retrievers have ever been pegged with it.

SM:
Fingers & toes crossed that this will be good news for Missy Morgan and her Momma too.
take care
Bill

I have been wondering the same thing. I'm still keeping my fingers crossed for the sweet girl

Vicki