Although trained therapy dogs can help patients physically and mentally, there is a risk the animals could be colonized with MSRA or other pathogens and become vectors for transmission.
While most patients can enjoy the benefits of pet therapy without risk of infection, those with cancer and other immune deficiency disorders are less protected. Researchers have pilot-tested a protocol that would make this activity safe for oncology patients, with plans now to test it in larger clinical settings.
“We really wanted to explore the risk of the therapy dog serving as a vector for spread of HAIs such as MRSA to these pediatric oncology patients,” lead author Kathryn Dalton, VMD, MPH, of the Johns Hopkins Bloomberg School of Public Health, said recently in San Francisco at an IDWeek 2018 press conference.
However, the study was not just observational, as Dalton and colleagues also tested an intervention that proved effective.
“We found that our intervention, which used antiseptic shampoo as well as antiseptic wipes during these visits, lowered the risk for children to become colonized with MRSA,” she said.
The therapy program in the study involved trained dogs who visit with patients receiving outpatient cancer treatment at Johns Hopkins Children’s Center in Baltimore. The dogs participate in frequent individual and group visits, raising the concern by one clinician that the animals could become vectors for spreading pathogens between patients or via the environment, Dalton explained. That sparked the study.
“In our study, the handlers reported an average of five other programs that they were involved with — other departments, other hospitals — as frequently as four times a week,” she said. “So, they are at high risk of being [colonized] with these hospital pathogens.”
Others May Follow
If the findings are borne out in the larger follow-up study, other facilities may follow suit. That is the hope of the moderator of the press conference, Chris Nyquist, MD, MPH/MSPH, medical director of infection prevention and control in Children’s Hospital Colorado in Denver.
“This study really speaks to me in an important way because we have had a longstanding specially trained pet therapy program,” Nyquist said. “One of my concerns and questions is how to balance the safety of the patient and the dogs who come in for visits. This study really gives us a beginning to start that conversation.”
Her program limits interaction between the dogs and oncology patients, which Nyquist hopes to now change based on Dalton and colleagues’ research.
“It’s really sad because our oncology patients are in the hospital the longest,” Nyquist said. “This study really brings us the opportunity to expand the use of pet therapy dogs to areas that have not been permitted to go in many of the hospitals.”
There have been cases of owners and patients being infected by their pets. And this study showed genetic evidence of MRSA colonization and transmission, although no infections were identified. But in most healthcare surveillance systems, infections rarely would be traced back to dog therapy. It is more likely that they would be ascribed to other patients or environmental sources. Still, concern about dog therapy makes intuitive sense, especially if the patient population in question is immune-compromised.
“The challenging part comes with these pediatric oncology patients who have a lower immune system,” Dalton said. “They are more susceptible to actually having an infection because of this direct contamination. We see issues with skin infections. There is the possibility of these patients undergoing procedures that could potentially result in problems from [MRSA colonization].”
Taking Dog Out of Equation
While there remains the risk for patients to spread MRSA among themselves or to become colonized by the environment, Dalton said the intervention “essentially removed the dog from the equation, which improved the overall safety of the visit.”
In the study, therapy dog handlers performed normal previsit practices for two control visits. They then transitioned to a decolonization protocol for two intervention visits.
This included bathing the dogs with chlorhexidine-based shampoo and using the same antiseptic in wipes applied to the animals’ fur periodically during the visits. The study included 13 visits overall that involved 45 patients and four therapy dogs.1
“In our intervention, we found a six-times higher risk to the patients who interacted closely with the dogs within our control visits,” Dalton said.
“Overall, regardless of the level of the interaction, our intervention had a 90% decreased risk of MRSA colonization in patients.”
After a pet therapy visit, patients had lower blood pressure and heart rate and reported improved mental health scores, Dalton reported.
“We saw benefits through our study both in decreased stress levels and reports of anxiety and pain,” she said.
“These positive benefits were not diminished by using the intervention,” she said.
“I’m happy to announce that because of the positive results of this pilot study, we were able to receive additional funding to do a larger study looking at multiple hospitals.”
Although the intervention with the antiseptics does not focus solely on the dogs’ paws, there is a logical correlation with hand hygiene, Nyquist said.
“This intervention of cleaning the dogs so they don’t become a vector for infection to humans is really important,” she said.
“For humans, it’s washing our hands. This is a way of washing the dogs.”
- Dalton K, Ruble K, DeLone A, et al. Abstract 160. Reduction in the Spread of Hospital-Associated Infections Among Pediatric Oncology Patients in an Animal-Assisted Intervention Program from a Canine Decolonization Procedure. IDWeek 2018. San Francisco, Oct. 3-7.
