These two Tom and Jerry episodes were consecutive: The Bodyguard was released on July 22, 1944. Puttin' On the Dog was released about 3 months later on October 28, 1944. The plots are also related.
From the IMDB website for Puttin' On the Dog:
This cartoon is often considered to be a sequel to the previous Tom & Jerry cartoon, "The Bodyguard", since it was released after it and also because at the end of "The Bodyguard", Spike the bulldog is captured by a dog catcher while in this episode he is seen in a dog pound.
In the start scene of The Bodyguard Jerry rescues Spike from the dog catcher's truck and he promises Jerry to help him if he whistles for help. But at the end he is again captured by the dog catcher.
My question: Why doesn't Spike know Jerry in Puttin' On the Dog? He had helped him in the prior show.