Many Americans love their dogs and cats, but almost three million companion animals are killed in shelters every year. If more people adopted cats and dogs, that number would be smaller, just as it would if more people spayed and neutered their dogs and cats. Perhaps if people knew the benefits they would get by saving the life of a shelter animal, more would do so.

In “Mutual Rescue: How Adopting a Homeless Animal Can Save You, Too,” author and animal advocate Carol Novello explains why saving the life of a dog or cat might just save your life, too. This book is filled with stories that will touch the heart of every reader and help animal lovers understand why we are so smitten with our four-legged companions.

Actually, to be more accurate, it might help explain to non-animal lovers why we animal lovers are so smitten with our dogs and cats (and birds and other animals). Why we consider them part of our family and mourn them grievously when they die. Why we often are willing to spend our last dollar for them and why some people who lose their home would rather live in their car than a homeless shelter because then they can keep their dog or cat. Many homeless people take better care of their animals than people who have large estates and plenty of money.

Novello explains why she first fell in love with animals and what her animals have meant to her during her life. She writes about leaving a high tech job in Silicon Valley to work with an animal shelter and how rewarding that work has been. And Novello shares stories with the reader — wonderful, important stories about how companion animals that were rescued from shelters or other situations changed the lives of the rescuers.

As Novello writes, “… the joy one person generates from adopting an animal can be contagious.” Harvard researchers showed that happiness is, indeed, contagious. Dogs have given people in abusive relationships the courage to leave; they have a remarkable capacity for love. When we lose someone close, often people don’t know what to say, or they say the wrong thing like, “At least he’s not suffering now,” or “It was meant to be.” Novello quotes Cori Bussolari, a psychologist who specializes in bereavement: “Animals never say the wrong thing.” New studies show that pets are actually part of our social support system, something that is indispensable in helping us deal with trauma or loss.

Something fascinating that Novello shares is that two studies found that humans’ and animals’ hearts begin to beat in synchrony when they spend a lot of time together, “a phenomenon known as heart coherence — providing preliminary evidence that rescue pets don’t just change our behavior; their life-affirming influence burrows deep into our body’s biorhythms, giving both animals and humans a respite from worry and providing physical renewal and relief.” In fact, one of the terrible things about loving a dog or cat is that they will probably die before their human companion does. Children often learn about death from experiencing the passing of a dog or cat or hamster. We mourn the passing of an animal companion much as we mourn the passing of a close relative or friend.

One study Novello mentions was done at the Central Missouri Humane Society. It shows that walking a dog can change the life of a person. This humane society has a special place in my heart. This was where, in 2010, my daughter adopted a senior herding dog who, during an adoption event, lay in his cage looking at her with his big brown eyes.

Bentley, a senior rescued dog

They told her that he would be euthanized soon, that no one wanted to adopt a seven-year-old dog. She did. And because of his terrible and destructive anxiety, she left him with me. Until his “retirement” last December, he came to school with me, helping students deal with their anxiety and their sadness and their need for unconditional love. But at 15 or 16, his body shakes too much for the stress of working at school. He is the smartest dog I have ever rescued. Bentley lived a whole life after his abandonment in Missouri. We were told that he was found in a field, shaking and covered with fleas and ticks. Never again. He herds the other three dogs when they run in our large backyard. And although his eyes are getting cloudy, and he sleeps a lot more than he used to, he leaps into the car for trips to the vet. I will always think of Bentley when I hear about the Central Missouri Humane Society, and thank them for saving him.

Like many dedicated pet parents, I firmly believe that all children should grow up with a dog or cat, or two or three. My own grandson has two dogs and two cats, and he has learned to be very careful around them. He walks around them, pets them gently, and helps feed them — and he’s only two and a half. When dog lovers see Facebook posts with a child sitting on a nervous-looking dog, we cringe, knowing that at some point, that dog will snap from the abuse. But responsible parents should know that having a pet for children is one of the best things parents can do. Novello writes, “Studies have shown that animals can ease children’s anxiety, provide them with a sense of responsibility, and give them a safe outlet for sharing their fears, worries, and challenges. Pets might even bolster children’s health. A number of recent studies have pointed toward the hopeful idea that youngsters raised with dogs or cats have a reduced risk of allergies, asthma, and ear and upper respiratory infections…pets can serve as a stabilizing influence and offer valuable lessons about responsibility, nurturing. loyalty, and love.”

For animal lovers like me, who have fostered countless dogs and cats, whose house is filled with animals, and whose daughter once commented on her childhood home, “it was great because no matter what room I’d go into, there was an animal,” Novello’s stories and conclusions are obvious. We know how our animals have changed our lives. We know the feeling of being loved by a creature who asks nothing in return. But for those who don’t know, this book will be eye-opening. It will share revelations that are like secrets — you only know them if you’ve experienced the love of an animal.

If enough people buy this book for someone who doesn’t have a pet, maybe, just maybe, this book could help ease the crisis in shelters across the country where there are too many dogs and cats and not enough homes. After reading this book, you might just be tempted to adopt (another) dog or cat. Or just foster. You will be saving a life, and it might just be yours.

Once you adopt your dog, or if you already have one, read “Unleashing Your Dog: A Field Guide to Giving Your Canine Companion the Best Life Possible” by animal guru Marc Bekoff and Jessica Pierce. That way the dog that saves your life will, in turn, have the best life ever.

Please note: This review is based on the final, hardcover book provided by the publisher, Grand Central Publishing, for review purposes.