Puttin' on the Dog is a one-reel animated cartoon and is the 16th Tom and Jerry short.
Tom chases Jerry until they run into a dog pound. The dogs angrily chase Tom and the cat hides behind a tree. Jerry, however, is sitting on Spike's back, and he taunts Tom. Tom notices a fake dog with a head attached near a pet shop. Realizing he must disguise himself in order to reach Jerry, Tom sneaks off and steals the head. He now walks and crawls like a dog until he reaches a lamppost. He puts the head to the side so if dogs see him, they'll think it's a dog, and peeks at the dog pound. Seeing it's all clear, Tom sneaks in through the bars, but loses the head in the process. He attempts to pull it out when Spike notices him. Tom puts himself back under the head and barks. Convinced that the dog is new to the dog pound, Spike walks away.
Tom successfully frees the head and runs to the center of the dog pound to keep a lookout. Jerry sneaks up behind him and imitates barking. Tom is startled out of his wits and has dug through some of the wall when he figures out it's Jerry. Jerry continues imitating a dog and then runs away. Tom chases after him and looks under various dogs to find the mouse, and then spots him in a bone-hat. Tom bolts after the mouse and Jerry hides. Convinced that the end of the dog bone nearby is Jerry in disguise, Tom grabs it and is met by an angry Spike. As Spike chomps down, Tom causes Spike to swallow his bone and flees to underneath a St. Bernard. The big dog goes to sleep and Tom pops out from under the dog - but without the dog head. Tom digs back under the St. Bernard, waking it up. Tom is hanging from the collar without the dog head and if anyone notices him, he's doomed. Fortunately, the St. Bernard notices nothing. Tom then attaches the head to his rear and pops out again, waking the dog again. The St. Bernard sees Tom sans head, but Tom switches ends and leaves. Tom hides in a barrel to keep a lookout, but soon notices that Jerry is doing the same. He breaks open the barrel and chases Jerry until Jerry hides in the fur of another dog. Jerry taunts him by swimming in the fur and gets Tom to dive in too. This wakes up the dog and he shakes both cat and mouse out of his fur, apparently confused. As the chase resumes, Jerry holds back, trips Tom, and gains the dog head for himself. Spike comes around the corner and briefly sees Tom's real head, but Tom hides it fast. Jerry leaves and Tom, apparently with no head at all, waves and follows after him. Thinking he's seen a living headless dog, Spike emits a terrified girl-like shriek.
Tom waddles after his "head", but fails to spot the pole in his way and he bumps into it, returning to normal. Seeing dog ears like the ones on the dog head in a nearby barrel, Tom grabs them and is met with an angry yellow dog. Tom ties up his mouth with his own collar and in a panic, runs away. Tom sees Jerry/head follow the path close to him and prepares to seize him; unfortunately, Spike is also coming around the corner. Tom grabs Spike and tries to fit him over his head. When he can't move after a few steps, Tom realizes something is up and sees the dog chomping at him. Tom hides behind a wall and soon spots Jerry/head. In his path, though, is a long Dachshund dog akin to a train stop. The dog apparently has two heads....until Jerry reveals himself and sticks his tongue out at Tom only to run into the dog's house. Jerry dashes off and Tom traps him underneath the head, but soon realizes that's his means of disguise and sticks it over his head just as Spike arrives. Jerry raises the head and turns the head in an effort to expose Tom until Spike lifts the head himself, whereupon Tom covers all of himself with the head and waddles off.
Tom lifts the head and whacks himself in an effort to flatten Jerry, but only causes a bump on his head. Because of this, Tom can no longer hide himself when Spike comes around, and finally sees through Tom's disguise. Jerry holds up a note stating "YES STUPID IT'S A CAT". Spike lets out an angry massive buffalo roar and the jig is up. Tom panics and digs a hole, but Spike digs him up with his large jaws. The chase wakes up all the other dogs, who join the chase themselves, as they are now on the warpath against Tom. Tom is chased to the top of a very high pole, with all the dogs barking at him. Then Jerry, who has donned the dog head, starts barking at Tom, but stop barking as they now hear Jerry barking. He loses the head, but jumps down, retrieves it and continues barking at Tom while the cartoon ends.