During the 1980s, buildings owned by Related Cos. limited residents to a single dog weighing about 50 pounds.

WSJ: Where Dogs Rule the Roost

In the streets of the city, he saw not a single cat or dog.

NEWYORKER: The Autobiography of J.G.B.

At the time, he said he was single and had a dog named Snoopy.

NPR: 'Charlie Brown' Actor To Serve Sentence In Rehab

He says many developers are using gyms, dog-walking services and even larger mailrooms to create a more social environment to lure single people.

WSJ: Looking Out for No. 1 - WSJ Mansion

More single-person households and more married women at work means that fewer households are able to give a dog the walks and other attention it needs.

ECONOMIST: Cats and dogs fight it out for prime pet position

Instead, a private school in Scotland has given sleek new iPads to every single one of its pupils to use in class and to even take home, nixing the excuse that the dog ate their homework.

FORBES: The School That Gives Kids Their Own iPads