Evaluation of the Risks of Shedding Salmonellae and Other Potential Pathogens by Therapy Dogs Fed Raw Diets in Ontario and Alberta

Abstract

Dogs that participate in animal-assisted interventions (AAIs), often called 'therapy dogs', commonly interact with humans whose immune systems are not functioning optimally. The advisability of feeding raw meat (including poultry) to these animals remains a highly contentious issue, in spite of increasing evidence that raw meat is frequently contaminated with Salmonella. We set out to determine if consuming raw meat influences the risk of therapy dogs shedding Salmonella and other pathogens. Two hundred healthy therapy dogs from Ontario and Alberta were enrolled. Between May 2005 and November 2006, fecal specimens were collected from each dog every 2 months for 1 year, along with a log of places visited, antimicrobial use within the home, dog health status and diet. Specimens were cultured for Salmonella, methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), extended-spectrum cephalosporinase (ESC) Escherichia coli and Clostridium difficile. Forty (20%) of the dogs were reported to have been fed raw meat at some point during the year. The incidence rate of Salmonella shedding in the raw meat-fed dogs was 0.61 cases/dog-year, compared with 0.08 cases/dog-year in dogs that were not fed raw meat (P<0.001). Controlling for therapy dog group, the repeated measures, and pig ear consumption and diarrhoea in the 2 months prior to specimen submission, dogs that consumed raw meat were significantly more likely to test positive for Salmonella at least once during the year than dogs that did not eat raw meat [odds ratio (OR) 22.7; 95% confidence interval (CI) 3.1-58.8; P<0.001]. Specific Salmonella serovars were more common among dogs that consumed raw meat versus those that did not include S. Typhimurium, S. Heidelberg and S. Kentucky. Raw meat consumption was also significantly associated with shedding ESC E. coli (OR 17.2; 95% CI 9.4-32.3). No associations between C. difficile, MRSA or VRE and consumption of raw meat were detected. We recommend that dogs fed raw meat should be excluded from AAI programmes, particularly when the programmes involve interaction with humans at high risk of infection or adverse sequelae attributable to infection. Furthermore, although AAI dogs may not be representative of the general population of dogs, we also recommend that feeding of raw meat to dogs is to be avoided in homes where immunocompromised people live.

Clostridium difficilein Food and Domestic Animals: A New Foodborne Pathogen?

“…C. difficile has also been isolated from household pets, including cats and dogs, and their environment [23,35,38,39].…”

Gastroenteritis and Food‐Borne Disease in Elderly People Living in Long‐Term Care

“…LTCF residents may be infected after consuming contaminated drinking water during community-wide outbreaks [73] or from dedicated water supplies [74]. Infected pets in facilities are a possible source of enteric infections, such as Salmonella and Campylobacter infections [75]. In a survey of dogs visiting Canadian hospitals, toxigenic C. difficile was isolated from 41 (40%) of 102 fecal samples [76].…”

Acceptance, Benefits, and Challenges of Public Health–Oriented Pet Business Regulations in King County, Washington

“…[21][22][23] Other concerning bacterial pathogens, such as extended-spectrum cephalosporinase E coli, have also been shed in feces from dogs fed raw meat diets. 20 Furthermore, many Salmonella isolates from feces of dogs fed raw meat diets have been found to be resistant to multiple antimicrobials. 18,20 The US Centers for Disease Control and Prevention has documented an increase in the extent of outbreaks of human salmonellosis linked to contact with live baby poultry sold for the purpose of backyardraising, often in urban locations, for eggs and meat and as pets.…”

“…14 Studies have repeatedly shown that pets fed raw meat diets have significantly increased shedding of enteric bacterial pathogens, primarily Salmonella, compared with those not fed raw meat diets. [15][16][17][18][19][20] Evaluation of raw meat foods fed to dogs and cats has shown a prevalence of Salmonella contamination between 6% and 80%. [21][22][23] Other concerning bacterial pathogens, such as extended-spectrum cephalosporinase E coli, have also been shed in feces from dogs fed raw meat diets.…”