I don't know. Something about a kiddie park.
4 seconds sound clip from the Mister Ed - Season 1, Ep. 4 - Kiddy park TV Series.
You can hear this line at 00:15:12 in the DVD version of the movie.
Quote context
[...]
- Hello.
- I've got some bad news. Your horse is missing.
- I think he's been stolen. Just before he disappeared, I heard a voice in his stall.
- I don't know. Something about a kiddie park.
- No, I didn't see anybody. That's what makes it peculiar.
- He told me he'd run off to a kiddie park.
- Have you seen my little black bag?
- I'm going to the kiddie park!
- Well, that's one way to settle the packing problem.
[...]