I have never witnessed coyotes here attacking a perfectly healthy large animal. I have seen them chase, but they are testing, not attacking. They are looking for weakness. Coyotes are opportunists. They are out after an easy meal that isn't much of a threat to them. Healthy animals put up too much fight, and the coyotes risk injury. They prefer the young, old, and sick animals that tire easily and are incapable of resisting an attack for long periods of time.

That said, I have seen coyotes chase perfectly healthy animals to try and cause an injury. The other day, I watch a couple of coyotes chase a herd of does back and forth across a barbed-wire fence. They were trying to make one hang on the wire. I have seen several deer carcasses over the years with front or back legs hung in the fence. The skeletons were still in one piece, but the carcass was picked clean to the bone with the cartilage still holding everything in place.