I also had a choking ferret. Eventually I scruffed her, pryed her mouth
open, and shoved my little finger down her throat until the stuck food went
down. That was my instinctive response, and I say - whatever works! She
recovered with no ill effects. I have also done the Heimlich on my dog who
"inhaled" a Milk Bone. It worked then, too.
[Posted in FML issue 1374]