barking mad

A dog is wailing outside my office. Its high-pitched long barks and intermittent moaning is bothering me. Whoever is pulling its chains must have tugged suddenly--I just heard the dog choke a little, its moaning interrupted, only to resume with defiant vigor, as though insulted.

My office is adjacent to a vet clinic, where that complaining dog is probably being hauled to. It sounded indignant in the beginning, but just now, desperate, as though it was screaming its innocence, "You're making a mistake!" it seems to say, "I'm not really sick! I don't need to be brought here! No, no, this is wrong!"

Since I can't hear the owner verbally scold the dog, I'm thinking maybe the dog is sick.

"No, no, this is wrong!"

Or delusional.

Or maybe I am again attributing meaning, where there is none.