SharonA, the horse in the Carol Burnett episode actually urinated - the wrangler stepped on camera with a bucket, and the flood obviously made its way to the front of the set, where Carol was standing. I did not consider that to be part of the “non-relieving” category, as it was live comedy, not an edited production.
It is, however, seriously hilarious. And while we’re in the variety show department, I remember Red Skelton in one of his Christmas episodes as Freddy the Freeloader (the street person in today’s parlance) who had only a blanket over his shoulders against the wintry cold. He saw a carriage horse (or meybe it had a sleigh) standing in the weather, and carefully draped his blanket over the horse’s back. Whoever wrote that scene was truly gifted, and obviously Red knew horses well enough to be able to put the blanket on without ruffling the hair or appearing frightened of the horse. Okay, back to the movies!