THE MAD DOCTOR (1933)

Mickey is jarred from sleep his pet, Pluto is dognapped by a weird cloaked figure and dragged to a mysterious castle. In pursuit, Mickey enters the keep and is skeletons and other horrors. Meanwhile, Pluto is taken to an abominable laboratory where the cloaked one is revealed to be a deranged scientist who wants to conduct morbid experiments.
Mickey, Pluto, and a chicken are the guinea pigs. The terror reaches a crescendo when Mickey is wakened from what was a nightmare and is reunited with his Pluto, safe and sound.