Therapy Dogs in Pediatric Oncology: Measuring the Impact

Sandra Yin

May 14, 2014

A large clinical trial of therapy dogs in pediatric oncology is underway to determine how animals can help in the management of ill patients.

The randomized controlled Canines and Childhood Cancer study is examining the impact of animal-assisted therapy on children newly diagnosed with cancer, their families, and even the therapy dogs who visit them. The trial will involve about 30 dogs and more than 100 children from 5 pediatric hospitals in the United States.

"It really promises to be a landmark study," said John Payne, chair of the board at the American Humane Association, which is running the trial, with funding from the Pfizer Foundation and Zoetis.

Details of the study were discussed at a press briefing in Washington, DC.

One of the children who took part was Bryce, a 5-year-old boy with leukemia undergoing treatment at the pediatric outpatient clinic at Monroe Carell Jr. Children's Hospital at Vanderbilt in Nashville, Tennessee.

Swoosh, a Pomeranian therapy dog

For 16 weeks, Bryce and his mother would meet up with Swoosh, a Pomeranian therapy dog, and his handler Michelle Thompson for a 20-minute session before his appointment at the clinic.

Jenny Greenwell, Bryce's mother, told Medscape Medical News that those Thursdays could be stressful. She sometimes had to give Bryce lorazepam to relax him before leaving the house because he knew what lay ahead. Besides weekly chemotherapy, some weeks he would get a spinal tap, "because the doctor wanted to see if any leukemia cells were still hiding out in his spine. Some of the days at the clinic were long," his mother said.

Bryce looked forward to his weekly visits with Swoosh. "It definitely eased some of his anxieties," she said.

Thompson said that typically, Swoosh would recognize Bryce, pull at his leash, and run straight for the little boy. If Bryce didn't pet the dog right away, Swoosh would crawl into his lap. It was as if Swoosh was saying, "I'm here, I'm here," she told Medscape Medical News.

Thompson allowed Bryce to give the Swoosh treats or brush him. A lot of the time, Swoosh would just sit next to Bryce while he told the dog handler about his new toys or games. "It was a really pleasant experience," his mother said, noting that Thompson shows a lot of interest in what the kids talk about while, at the same time, trying to engage the dog with the children.

Bryce talking to Swoosh

In the beginning, Thompson didn't think Bryce cared for Swoosh, because he "wasn't all that demonstrative about his affection" for the dog. But as he got to know the dog, that changed. It became clear to Thompson that Bryce really liked Swoosh, and would sit next to him, pet him, and talk about him. "Really, everybody loves Swoosh," said Thompson. "He's such a sweet dog."

It's an experience Greenwell recommends. "It really helped Bryce," she said. For that 20 minutes, he wasn't thinking about his treatment. "He was talking about his toys, brushing Swoosh, and feeding Swoosh treats," she said.

The experience helps parents too. The dog therapy gives parents a chance to sit back, relax, and not worry about their child, because their child is content. "For a moment, their child is happy and stable," Thompson said. "Everybody gets a break from the treatment in that time period."

Psychological Effects Linger Long-term

Besides physical concerns, children with cancer and their caregivers and families are prone to psychological issues, such as stress, anxiety, loneliness, trauma, depression, and strain in their significant relationships. "Although the physical effects associated with this disease may greatly improve for these children over time, the psychological effects linger long term," said Amy McCullough, national director of humane research and therapy at the American Humane Association.

Studies have documented the benefits of animal-assisted therapy, which include relaxation, decreased blood pressure and heart rate, and reduced pain. But most have been anecdotal, and the field has consistently struggled to conduct and develop rigorous research.

"There are crucial research gaps that must be filled if animal-assisted therapy is to be considered a safe feasible treatment option for children with serious illnesses," said McCullough.

A tiny pilot study conducted to determine the feasibility and optimal design of a full clinical trial of animal-assisted therapy has already revealed some findings.

The therapy appears to help the entire family cope with the effects of cancer, McCullough reported. Findings from focus groups suggest that therapy dogs provide families with a sense of normalcy while they're in the hospital.

However, after 15 minutes, dogs tend to exhibit signs of stress, such as panting, lip licking, and looking to the handler for guidance, so that might be a better duration for sessions. In addition, 20 minutes might be too long for younger children.

In postsession surveys, distress scores for children and their parents were low (1.6 and 1.8, respectively, on a 5-point scale).

After the pilot study, the researchers updated the hypotheses for the full study. They expect that children and their parents or guardians will experience less stress and anxiety and will have a better health-related quality of life during chemotherapy sessions when they receive animal-assisted therapy than when they do not. The researchers also expect participating therapy dogs to exhibit minimal distress over the course of the study.

For the full trial, the blood pressure and pulse of the children will be measured, and anxiety and quality-of-life inventories will be administered to the children and their parents or guardians. Animal handlers will collect their dog's saliva at the beginning of the study to establish a baseline cortisol measurement, and then after each session with a child. Handlers will also complete self-report forms on the dog's behavior and recount what happened during each session with a child. The dogs will be videotaped at specific time points throughout the study so that salivary cortisol levels and behavior reports can be compared.

It is expected that the full clinical trial will take 12 to 15 months and that the findings will be released in 2015.

Allowing Children to Be Children

"With a therapy dog visiting, young cancer patients stop being patients and become children again," said Stephanie Cooper-Greenberg, another therapy dog handler. The dogs provide a much needed break from the crushing demands of treatments, tests, and infusions, she added.

"We've had amazing things happen," said Cooper-Greenberg, whose Dalmatian visits the pediatric oncology unit at The Johns Hopkins Hospital in Baltimore. "The reserved child or reserved older patient or psychiatric patient, or whoever, just comes alive when they see the dog," she said. "It breaks down social barriers and isolation."

Bryce and Swoosh

Janet Brake, a doghandler based in Laurel, Maryland, who works with her Italian Greyhound Peppe, noted that dogs can read human body language and react to people differently. When Peppe came upon a woman at an Alzheimer's facility who seemed unresponsive, he put his front paws on the wheelchair and started nudging his wet nose against her arm. The woman started laughing. Two assistants told Brake that they had not seen the woman react to anything in years. "I cried all the way home," said Brake.

Therapy dogs are trained to remain unflappable in the face of odd human behavior, said Cooper-Greenberg, who has helped train 13 dog therapy teams.

The experience with Swoosh and Thompson gave Bryce and his mother something to look forward to — even on clinic days, Greenwell noted. In fact, one day as they were rushing to their appointment, Bryce said, "I don't want to be late for Swoosh."


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