TORONTO - Dogs, cats, even miniature horses and alpacas occasionally can be found roaming the halls of hospitals and long-term care facilities, as part of animal visitation programs that provide affection, comfort and distraction for willing patients and residents.

But with increasing numbers of scientific studies suggesting furry visitors can pick up and perhaps spread pathogens like Clostridium difficile and Salmonella, experts think it's time for evidence-based recommendations on how animal visitation programs should be run.

Canadian and U.S. experts are meeting in Toronto on Tuesday to debate and hopefully approve detailed guidelines aimed at minimizing the infection risks to the patients, the pets and the owners of animals that visit hospitals and nursing homes.

One of the organizers, Dr. Sandra Lefebvre of the Ontario Veterinary College in Guelph, thinks this type of infection control guidance is overdue.

"Therapy dogs and other programs have spread really rapidly, because they are so popular and people love them. And the problem is that we haven't kept on top of the infection control practices,'' said Lefebvre, a veterinarian and scientist who has conducted key studies looking at what types of bacteria, parasites and other types of bugs therapy animals can pick up and perhaps transmit during their travels.

"We haven't said, `OK, just a minute here. What are the potential problems? And do we need to do something about that?'''

"We require people who are going into hospital to apply hand sanitizer before they go in, but animals get in without any kind of screening like that. So it makes common sense that we would have to take some preventive measure to help minimize the risks.''

A list of recommendations, drafted with help from the U.S. Centers for Disease Control among others, will be debated by participants, who include researchers, animal behaviour experts, representatives of Canadian and American infection control associations and groups that run animal therapy programs.

Meeting organizers support animal visitation programs and are not recommending they be scrapped.

But they said issues up for discussion include restricting the programs to healthy animals that have been tested to see that they have the right temperament to visit hospitals, where they could be subjected to loud noises and approaches from a large number of strangers.

"That's something that may be overlooked when it comes to health risks, that bites and scratches might actually be the biggest risk,'' said Dr. Scott Weese, a colleague of Lefebvre's and a leading researcher in the study of antibiotic resistant bacteria in companion and farm animals.

Lefebvre has been bitten several times by therapy dogs, including one she was testing for pathogens.

Other areas the guidelines are expected to cover include the recommendation that anyone handling therapy animals sanitize their hands before and after contact, and that animals which are fed a raw meat diet -- which carries a high risk of Salmonella infection -- be excluded from visitation programs, Lefebvre said.

As well, the meeting is expected to make recommendations on which animals are appropriate for hospital visitations and which are not.

"Farm animals you can be fairly sure will be excluded,'' said Weese, referring to alpacas and miniature horses. He said it is likely the recommendations will suggest limiting access to dogs and cats and perhaps some other small animals.

The intention is to come up with consensus guidelines for hospitals and long-term care facilities aimed at minimizing the risk that animals will bring pathogens into or pick pathogens up in hospitals, potentially spreading them from patient to patient or from hospital to home or even becoming ill themselves.

Studies Lefebvre has done have shown therapy dogs can carry a variety of pathogens, from superbugs like methicillin-resistant Staphylococcus aureus (MRSA) ) and vancomycin-resistant Enterococci (VRE) to C. difficile and Salmonella.

Whether they spread the bugs to people is still under investigation. And an infection control expert who used to work at the CDC in Atlanta said Monday he's not convinced animals are playing a large role in spreading these pathogens in health-care facilities.

"To be perfectly honest there have been very few if any outbreaks recognized associated with such animals in recent years,'' said Dr. Bill Jarvis, who added the majority of hospital-acquired infections are spread on the hands of health-care workers.

But Weese countered that it isn't clear how big a role animal visits might be playing in spreading infections, because infection control teams haven't looked at visiting dogs and cats as a source of transmission for bugs like MRSA and VRE.

"It's possible these transmissions have been occurring below the radar, because they're not considered animal associated diseases,'' he said.

Visitation animals could also be taking bugs home with them, Weese noted.

"So a dog picks up MRSA, VRE, C. diff, whatever in a hospital it can then be a focus of community infection. It can pass it on to people in the household or to other dogs. It's potentially one more link between the human health-care system and the general population.''

The director of infection prevention and control at Toronto's Hospital for Sick Children -- which has a dog visitation program -- said guidelines would be very useful.

"I think definitely people would say the advantages (of the visitation programs) outweigh the disadvantages, especially in children and the elderly -- just somebody to snuggle and cuddle up to, in a very non-threatening way as the human-animal interaction can usually be,'' Dr. Anne Matlow said.

But Matlow said hospitals don't know if the animals are spreading pathogens, mainly because they haven't factored them into investigations of hospital spread.

"To be able to distinguish or differentiate whether it was acquired from the animal proper, because the dog came in with it, or because the dog was a vehicle carrying it from Room 1 to Room 5 ... we just don't know.''