This cartoon marks the debut of Spike and Chester, two dogs would chase Sylvester not once, but twice. Their second and last appearance would be in the 1954 short, "Dr. Jerkyl's Hide".
A black panther is actually a melanistic colour variant of both leopards and jaguars. The big cats show an excess of dark coloring, making them appear to be pure black, but their characteristic spots are also present in their coats.
Apart from singing a bit, Sylvester does not speak in this short.
The audience never does learn what happened to the escaped big cat.
The newspaper announcing the panther's escape is dated Monday, Feb. 2, 1951. (This short was released in 1952.)