Cracker, I'm in the same boat, if mine are just hunting and I blow this whistle, mine will come in but if they are on a hog, its takes a bit more than my whistle to get them off. I can usually call them off of cattle with it when catching cattle with these dogs though. I don't understand why they will call off cows and not off pigs with it, probably something to do with the pig squeeling, but not sure. Got mine from
www.bordercollie.com