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A healthy toy poodle that regularly visited hospitals and long-term-care facilities in Ontario was found to be colonized with a virulent, epidemic strain of Clostridium difficile. This is the first report of a dog carrying this particular human pathogen.


C. difficile was isolated from a fecal sample collected as part of a study to evaluate pathogen carriage in pet therapy animals. Testing revealed that the poodle was carrying a strain that's been implicated in worldwide outbreaks of highly virulent C. difficile- associated disease (CDAD), according to the CDC.


No evidence links the dog to any human case of CDAD, although one facility that the dog visited reported an increase in CDAD around the time the dog's specimen was collected.


Researchers speculate that the dog became colonized from the health care environment or from being touched by contaminated human hands. They note that no studies have demonstrated interspecies transmission of CDAD, but recommend that those investigating "the dissemination of this virulent strain and its movement into the community consider the role of animals."




Epidemic Clostridium difficile strain in hospital visitation dog, Emerging Infectious Diseases, SL Lefebvre, et al., June 2006. Available at