I have a good hunting friend in Spokane.He has had to put down two chessie bay retreivers previously.Great dogs.I went in with on a new pup last year.In a regular trip to the vet this spring he was informed of a strain of virus that was unique to the Palouse.An area that we hunt regular.He had the pup vacinated for this virus.The symtons of it were very similiar to what his last chessie died from. I hope this info helps to prevent someone elses heartache.