Season 6, Episode 23: "The Face Painter"

Mr. Kramer, thanks for coming.

So, what did you wanna see me about?

Well, Mr. Kramer, to get right to it...

...we're having a bit of a problem with Barry.

-Barry? -The chimpanzee.

Well, what's the problem?

Well, he's not functioning the way he normally does.

He seems depressed. He's lost his appetite.