He never talks, only appears to drop off new dogs at the pound, and is a parody of Wild West sheriffs. Because of his mysteriousness, not much is known about the dogcatcher. No other dogcatchers are ever seen dropping dogs off at Shelter 17. A western guitar chord sometimes accompanies his appearances.
Ketchum's first appearance was in "The Yipper Caper", becoming the first human to be seen on the show, dropping off Yipper at the Shelter 17 (McLeish and Olaf appear a couple of seconds after he arrives). Lucky describes the dogcatcher as "[...] kind of rough, but he's not so bad once you get him trained".
In "Lucky Has to Move", Ketchum showed actual emotion for once in his career- after McLeish told him to "stop bringing puppies" and to go "get a girlfriend or something", Ketchum smiled immensely and promptly drove off without a second thought.