What does "gone to the dogs" mean — and why is it funny?

informal

Meaning

Said of something that has declined badly and fallen into a poor or ruined state.

Where it comes from

An old phrase. Scraps and spoiled food not considered fit for people were once simply thrown to the dogs.

Why it is funny

The mild humor is the slow slide the image captures. Something once respectable ends up as table scraps tossed to the dogs — a fall from grace measured entirely in leftovers.

Used in a sentence

"He says the old neighbourhood has completely gone to the dogs."