I have had some choke issues in my sheep in recent years. It almost always is with grain though, not hay. There DOES seem to be some genetic component that I have noticed. One ewe, plus her daughter and granddaughter will all do it. I am not sure if it is a defect in the structure of their throat or if they are all just gluttonous hogs that eat too fast. I have have had a couple sheep over the years that would do it repeatedly on hay and then quit. I suspect in those cases it was caused by an injury to the throat. Maybe from swallowing something too big or sharp? Pipestone has suggested that the puking/cud spilling that can accompany choke may be a vagus nerve issue. I wish I had more answers for you! If they are bolting grain, you can slow them down by wet feeding, but ewes that choke on hay are harder to manage.
