What events from the black cat seem to prove the wife and superstition about cats to be correct?

In Edgar Allan Poe's "The Black Cat," the protagonist's descent into madness and violence seems to validate his wife’s superstitions about cats. The initial incident with the first cat, Pluto, where the protagonist gouges out its eye, leads to a series of ominous events, including the cat's return and the protagonist's escalating guilt and paranoia. Ultimately, the haunting presence of the second cat, which bears a striking resemblance to Pluto, culminates in the protagonist’s downfall, reinforcing the idea that his actions have invoked a curse and that the superstitions surrounding cats hold a sinister truth.