The Painter and the Pointer (1944)

Andy Panda is the painter and his dog, Butch, is the pointer, and Andy is trying to paint a portrait of Butch doing what a bird-dog is supposed to do...standing still and pointing to the game-bird. But Butch won't stand still. Andy's solution is to rig a gun to go off if Butch moves a muscle. Butch gamely resists all temptations to move but a couple of spiders carry him off in their web, with the gun going off repeatedly and peppering Butch's posterior.