Could you provide an example of what you are referring to?

I don't think I've ever noticed dogs in early American political cartoons, but I do know that dogs both domesticated and semi-feral, were common fixtures of both urban and rural life in the 18th century. Dogs in art could imply both servility or loyalty, or both, depending on context. That said, the late 18th century was the time when, at least in English-speaking cultures, the idea of dogs as "household pets" (existing only as a luxury good) rather than "working animals" like hunting dogs or rat-catchers, began to appear. This article published by the Colonial Williamsburg Journal, discusses the place of domestic dogs in 18th century art and culture.