I heard ivomec was first used on horses...they later found out it would protect dogs from heart worms.

Like I said a buddy that had a grey hound kennel used ivomec on all his dogs....if its good enough for a pure bred racer it's good enough for your mutt of a hunting dog.

Here's a tid bit of information on grey hound breeding my buddy told me...I remarked to him boy you'd be set if you had a champion pair a greyhounds to breed from...his reply was that they learned years ago to never breed the same dogs more than once.

He told me they'd reach to the Champions brother or sister but never repeat breeded.