Randy-dog ethics

I only knew my great-aunt a little when I was pretty young. One of the expfressions she used a lot in her conversations with my mother and grand mother was "of course he had Randy Dog ethics". She said it almost every time they visited.

Wh or what was Randy Dog? I have often suspected he was a cartoon character.

So what did she mean? And are there other expressions that say the same thing in other words?

There is no cartoon. What she was referring to was a person, as the definition suggests, having a coarse manner,ie lustful,lecherous

The adjective "randy" means "lascivious, bawdy" (American Heritage Dictionary). A similar expression is "So-and-so has the morals of an alley cat."