Green’s Dictionary of Slang

(orig. US) a small scoop used by dog owners to remove a dog’s excreta from urban pavements or parks.

1978		Time 14 Aug. 73: Retailers reported brisk sales of sanitary devices ranging from 15c disposable cardboard shovels to $11, long-handled pooper scoopers equipped with a flashlight for nocturnal emitters.
1993		K. Lette Foetal Attraction (1994) 145: What you object to is all the shit. Well, if you hate the pooper-scoopers, you’ll need a pooper-bulldozer with a baby.
1997–2002		Alt. Eng. Dict. 🌐 pooper-scooper (noun, count) small shovel for picking up dog feces.