Jim Nelson and René Agredano dropped everything to travel with their dog, Jerry. To get Jerry's full story, NATURE spoke with René in February 2009.

Here are some recent dog photo entries to our "Why I Love Cats and Dogs Photo Contest." We want to see pics of YOUR charismatic canine too! Find out how to enter.

We asked our Twitter followers to weigh in on a very important question: Cats or dogs - and why? Here's what they had to say.

You've already bragged to friends and family that your dog or cat is the cutest in the world -- now prove it! Send us your photos.

What does the way we treat our pet dogs say about ourselves? Sarah Wilson came up with nine different behavior patterns seen in dog owners.

View additional resources for NATURE's "Why We Love Cats and Dogs."

Lessons in the guide use the programs as a starting point for discussions about the domestication of dogs, selective breeding, and the ways in which humans and dogs work and live together.

Download wallpaper from NATURE's "Dogs That Changed the World."

Students will use critical thinking to determine which breed of dog would best fit their personality and living situation, then write a short story from a dog's perspective.

See the production credits for NATURE's "Underdogs."