Neither Robert Clampett nor Chuck Jones cared much for this short, not because they thought it was bad, but because it used an iron lung as a gag prop at a time when polio deaths were on the rise.
Daffy breaks the fourth wall when claiming to the audience that he has a sheepskin (university degrees were originally hand lettered onto animal parchment) and a license (in this case, a license plate and not the medical variety).
The hospital name is a pun on two popular sayings: a stitch in time saves nine, and as ye sow, so shall ye reap.
Both cartoons and films of the era used innovative editing techniques at times, such as the wipe, and the iris (seen here).