Matrons eyeglasses on the dog maybe? So then the joke is on matron?
Have it a big dog and dress it up in matrons uniform, then the filthy doctor who is always after pinching her bottom gets his hand bit at and the dog chases him barking?
Then at the end you see the nearsighted Janitor having a drink fest with dog matron?
Giving dog matron a bit of a cuddle.
Telling her her beauty regimens working a treat, why isn't she looking just like a young pup?
Maybe it was only that he dressed up the dog in matrons clothes?
He said he weren't meaning to upset the animal, but that head one went and kissed it...