Well you could be referring to catching coyotes with greyhounds. It is a very common practice here in kansas guys with pickups will chase coyotes out of cover into open pastures where they can get somewhat close then they will let the dogs, greyhounds, out of a specialy made dog box on a flatbed pickup that has a rope coming into the cab to open the door. The dogs will catch and fight the coyote, some guys have a special kill dog that is usually a bigger dog mostly mutt breeds that will actually kill the coyote. This style is sometimes looked down on but can be very fun and there are enough yotes around here that there is no negative impact.