Excerpt: 'Through a Dog's Eyes,' by Jennifer Arnold

Aug. 17, 2010— -- Jennifer Arnold, who has trained service dogs for the past 20 years for people with physical disabilities, offers a window into the world of "man's best friend."

Arnold, who believes that dogs are attuned to their owner's needs and emotions, shares tips she thinks every dog owner should know.

Read an excerpt of the book below, and then head to the "Good Morning America" Library to find more good reads.

The request to see Dr. Nick, as the children called him, came early on a Monday. An eight-year-old boy in Phoenix had fallen off his skateboard and was clinging to life. Dr. Nick, with his old black medical bag, was on the next flight from Atlanta to Phoenix. It was my privilege to accompany him on this trip, as I had on many trips in the past. It was an experience that profoundly changed the way I understood the emotional life of dogs.

Because Nick had been trained as a service dog, he had legal access to places other dogs could not go. So, while the child's own dog was not permitted in the Phoenix hospital, Nick was welcomed. He was there on a mission so tragic it still hurts to this day. He was there to help this precious little boy die.

The child had no brain function. His stricken parents knew it was time to allow the life- sustaining machines to be turned off. The boy loved his parents mightily, but his best friend on earth was his dog. Because his dog was not allowed to be with him as he died, his parents had asked for Nick.

As soon as Nick entered the hospital room, he dropped his bag, carefully maneuvered himself around the tubes and wires, and jumped gently up onto the bed to lie quietly against the boy's side. I never gave him any direction; Nick just did what he instinctively knew to do. He stayed on the bed without moving for more than two and a half hours. Sometime during that afternoon, the boy's mother asked those of us in the room if we had put her son's arm around Nick. We toldher that we had not, but indeed the child's left arm was now draped loosely across Nick's big neck. Nick had nuzzled himself there. When the child was pronounced dead, his devastated mother broke. Her wail was unlike any noise I had ever heard. Without even seeming to displace the sweet little arm across him, Nick managed in one move to fling himself into the mother's arms. Together they stayed huddled, as if on a life raft, until the mother was led into an empty room nearby.

The nurses thanked Nick and me for coming and told us we were free to leave. In something much like shock, I stumbled to the elevator with Nick walking proudly beside me. I can remember being relieved to see that he had made it through the ordeal without too much visible trauma. But as soon as the elevator doors closed and the two of us were alone, Nick collapsed to the floor with a moan. He remained there as the elevator doors opened into the lobby. No amount of encouragement or bribery made him move. He did not look at me but rather through me, with glassy, vacanteyes. I started to worry.

With the help of a hospital intern, we carried Nick to my rental car and placed him gently on the backseat. In my heart, I felt like his reaction was one of grief, but my brain kept reminding me that he was a dog and I shouldn't anthropomorphize his response. How could he understand what had happened? If dogs are motivated only by seeking pleasure and having their own needs met, then why would Nick be so overwhelmingly sad? That little boy and his familymeant nothing in terms of Nick's life.

Fearing he had suffered a stroke, I phoned a nearby veterinary clinic. A young vet helped me get Nick into a clinic exam room and, as I relayed the events of the afternoon to her, she proceeded to examine him. She found nothing wrong with him physically. He even stood up for her and finally walked with me back to the car. As the veterinarian followed us, she explained that Nick was perhaps upset because he knew I had been distressed. That would fit right in with the concept that dogs worry only about what might affect them, I thought. She explained that there really was no way to tell if a dogwas truly feeling emotion. We could only describe the dog's behavior but could not speculate as to any inner feelings that might be causing the behavior.

I started to leave, not completely persuaded by her explanation but at least confident that Nick wasn't physically ill. I could see by the look on her face that she wasn't convinced by her textbook answers either. So I wasn't surprised to see her raised arm as I began to drive off, signaling me to stop. She leaned in and looked again at Nick in the backseat. Then she confided that her gut instinct was that Nick was experiencing grief for the child, the family, or both, and his behavior wasn't about his concern for me, at least not exclusively. She went on to say that I should be careful about putting him in such emotion- laden situations in the future, since he seemed to feel things so deeply. At least, she said -- ever the scientist -- his behavior indicated as much.

Trying to be a "true professional" when I started Canine Assistants, I was very careful not to credit dogs with any abilities or capacities not scientifically proven. I was so afraid of being perceived as an overly emotional dog person that I refused to open my mind. Well, as usual, Nick and the other dogs opened it for me. I began to realize that many things I know to be true haven't yet been proven scientifically. Of course Nick had been sad. I knew that in my heart all along. He had looked sad. His body literally sagged under the weight of his grief. He may have been concerned about me too, but he was undoubtedly experiencing his own intense emotions.

Time has taught me that dogs, like humans, are emotional creatures. Just watch a dog whose beloved owner returns home from a trip -- the dog jumps for joy.

Will it ever be possible for us believers to prove that dogs experience emotions? Well, yes and no. As Patricia McConnell says in her fabulous book, "For the Love of a Dog," "Emotions are slippery things." She is absolutely correct. Does your spouse have emotions? How do you know? Can you actually experience what he is experiencing internally? If not, then how can you know for certain that he has emotions?

Of course, it's simple: You ask him. Therein lies the problem with animal emotions. Not only can we not experience what they experience emotionally, we can't ask them what they're feeling. However, we can exercise a little common sense.