What is "catch dog"

A catch dog is a specially trained dog that is used to catch large animals in hunting, working livestock, and baiting.

As hunters, catch dogs are contrasted with bay dogs who corner prey animals and alert their handler by howling, or baying. Catch dogs are typically outfitted with chest armor to prevent being speared by the boar's tusk, and neck armor to prevent neck injury.

As livestock dogs, catch dogs use their weight and teeth to immobilize live animals so that they can be captured, or literally hogtied, by the dog's handlers, who may be stockmen, hunters, butchers, or farmers.