whether i was giving him the best life possible. i said i need to go on a road trip with my dog and bond with him. >> reporter: that's how ben decided to take his labrador mix casey on a road trip. but this wasn't your average road trip. it was a 13,000-mile, 32-state, four-month motor home adventure across america. and it's all in the new book "travels with casey." the author, a "new york times" magazine writer, wanted to better understand his relationship with casey. but he also wanted to explore what makes america dog crazy, just how crazy? there's one canine for every four humans in the u.s. more than 50 million households have a dog. that's the highest dog ownership rate on earth. and americans now spend roughly $40 billion on dog products and services each year. >> we do spoil our pets in ways we didn't really used to and, you know, dogs are now considered family members and a lot of people consider them their children.