Why DO we love cats and dogs so much? PBS documentary explains (VIDEO)

The Carrolls with their pets, Winston and Bubba. (Photo courtesy PBS)

How far would you go for a beloved cat or dog who is dying of cancer? Would you drop everything to take your pet on a last hurrah across the country? Sell your home and business to finance the treatment and travels?

That question is explored in a new PBS documentary that examines the love we humans have for the felines and canines in our lives.

Entitled, "Why We Love Cats and Dogs," the documentary uses interviews with scientists, animal experts, and every day people to explore the depth of the human-animal bond. 

We meet Jerry, a three-legged dog who lost a limb to cancer, and the human couple who loves him. Learning that Jerry only had a few months to live, his owners, Rene Agredano and Jim Nelson, decided to give up everything and spend their last days with Jerry showing him a good time on the road on a cross-country vacation.

"A lot of people thought we were nuts when we sold our house and our business and said we were going to travel for a while. How far do you go for a dog? He's not human, he's not a kid. But he means so much to us. I can't picture our lives without him.

--Jerry the cancer-stricken dog's owner

Sound crazy?

Americans own a staggering number of pets: 73 million dogs and 90 million cats, according to a new documentary by the NATURE series on PBS. 

"Dogs are some of the longest relationships we have," says Sarah Wilson, dog behaviorist, psychologist and author, pointing out that our pets often outlast marriages. If we're lucky, our dogs and cats can live up to 10, 15, 17 years, while the average marriage lasts a mere three and a half years.

Marc Bekoff, a renowned evolutionary biologist and author, has spent the last 38 years studying the social behavior of dogs and coyotes. By studying the scientific, physiological, neural and hormonal responses in humans and animals, Dr. Bekoff explains how it is that we become attached to our dogs, and are able to share their feelings and emotions.

While cats have gotten a bad rap for being independent and snooty, they can be taught to be "as responsive and trainable as dogs," says Dr. Nicholas Dodman of the Tufts Cummings School of Veterinary Medicine. 

An interview with one young man reveals how his cat saved him from a downward spiral of alcoholism. "I would drink all day and my cat would wait outside my bedroom door for eight hours. It was having to look him in the eye knowing what I was doing to myself that got me to seek help for that problem and not isolate myself."

Cats, many people in the documentary say, have a "soulfulness and depth of spirit." Yet, they are killed in larger numbers in the shelters.

Dr. Emily Weiss of the ASPCA in New York City estimates that five to seven million animals enter the shelter system every year. About 60% of the dogs, and 70% to 75% of the cats are killed each year. By using a system that studies the behavioral traits of cats--assessing their energy level, playfulness, persistence and motivation type--Dr. Weiss is able to match each cat with the most suitable owner, decreasing the number of felines that are killed each year in the shelter. 

"Why We Love Cats and Dogs" premieres on the PBS channel on Sunday, February 15 at 8 p.m. EST. Check local listings. 

Watch part of the documentary now...