My 14-year-old border collie was so crippled with arthritis that I had to lift him out of the car and gently set him on the pavement. One last hug, and full of trust, he struggled across the parking lot to the stranger standing beside an open door.
It was the last time I saw him. Constant pain had taken the joy from his life. Yet until the end, he was my constant companion, in some ways my closest friend, and I wondered if I had done the right thing.
Was I being selfish, having him put down because I could not stand his pain anymore? Could a different vet have given him another year or two? Was killing him really necessary? Doubts. Grief. Guilt.
Nearly all of us have gone through that process, trying to decide if the time has come to let go. It's one of the hardest decisions we ever have to make. Pets are not just other animals. They become members of our family, soul brothers, devoted companions.
It can be a very lonely decision, but researchers at Michigan State University in East Lansing are developing the tools we need to help us make the right choice. They have teamed veterinarians with pet owners to find out which symptoms observed by the owners are supported by the science observed by the vets.
"The owner knows the pet, and the clinician knows the science," veterinarian Maria Iliopoulou of MSU said in releasing a study.
The study, published in the Journal of the American Veterinary Association, followed 29 dogs from six months prior to a diagnosis of cancer and through weeks of chemotherapy to see which signs of distress, as observed by the owners, were clear indicators of the seriousness of the pet's condition. They found three areas in which the clinicians and the owners were in close agreement.
The first, and least surprising, is the clinical diagnosis. Owners would have to have some level of confidence in the quality of the vets to pay the substantial bills that would inevitably follow, so the science informed both sides.
Two other areas of agreement are likely to be equally useful in helping the owner reach the right decision. They are:
Does the pet still like to play?
Does it still seem happy?
Only dogs were used in the study, chiefly because the clinic sees far more dogs than any other animals. And only cancer was studied because changes in the dog's health can be measured over a relatively brief period of time.
"Those were the practical reasons for using only dogs and cancer," Iliopoulou said in a telephone interview. But the findings probably apply to a wide range of pets, she added.
One of the main reasons we pick pets is we want them to play with us, so "play behavior," Iliopoulou said, "is easily identified. If the animal doesn't play, something is wrong. If play behavior comes back, the dog is getting better."
So whether or not the pet wants to play should be obvious to the owner, and both the vets and the owners who participated in the study agreed that playing is a key symptom.
But happiness? How do you know if your dog is really happy?
This sounds a little tricky, because as Iliopoulou conceded, "it is practically impossible to define happiness for humans," so how can we define it for dogs? That isn't necessary, she added. You can easily tell whether your pet, or a close friend, is happy, even if you can't define it.
"It might be something totally different for me than it is for you," she said. "However, people who know me know when I am happy or sad. I know when my dogs are happy or sad, even if I can't define happiness for my dog."
Happiness, it seems, is like that old definition of pornography. You may not know how to define it, but you know it when you see it.
The study involved 29 dogs, or patients, as the vets call them, that were diagnosed with cancer. The owners filled out two surveys. One asked the owners to describe what their animal had been like six months before the diagnosis, and the second evaluated the pet's "quality of life" at the time of the diagnosis.
Additional surveys, of both the owners and the vets, were conducted three weeks and six weeks after the initiation of chemo.
Play behavior, and the perception of happiness, as well as the clinical findings, surfaced as the strongest indicators of how the animal was progressing.
Perhaps surprisingly, only one of the 29 dogs had to be euthanized during the study period. Two thirds of the dogs responded favorably to the treatment, although one third did not. Iliopoulou is planning a follow-study to see how the dogs fared over a period of several months, and she plans to continue her research on the human-animal bond.
This is a small study, involving only dogs, and only cancer, so it's hard to make broad conclusions. But the researchers believe that the study clearly shows that teaming vets with owners to continually evaluate the pet's "quality of life" can make that dreadful decision a little easier.
Of course, that's a difficult course for many to follow, because long-term medical care for a pet can rival human health care costs.
But the basic findings of the questions that need to be answered might be helpful for many owners.
Does the pet still like to play? Does it seem happy?