Well...this is interesting. I can't find the blasted thing! I saw it on TV and I can see the reviews about it but no video footage is online
The episode is Comedy Cowboys. A horse sneezes multiple times thanks to a bad hayfever allergy. It actually purposefully dives its nose into hay to sneeze.
Another few episodes of Hong Kong Phooey have pepper sneezes from the two main characters, the cat and Hong Kong Phooey himself.