This has been attributed to Bennett Cerf. Many variants exist.

Lowell, Massachusetts, is an old New England Mill town. Many of the Mills have been declared National Historical Sites and are included in a Federal Park (true!). The problem was what to do with the other mills, and how to attract more tourists to the area. One bright young marketeer pointed out that Germans like to travel with their dogs, and this was difficult in the U.S. Why not make the mills into canine hotels? he suggested. The plan was adopted on a trial basis, but not without some skepticism. Several months later, the skeptics approached the young man to ask how the experiement was going.

“Just listen!” he said. “The Mills are alive with the hounds of Munich!”