Who let the dogs In? An epidemiological study quantifying domestically sourced and imported dogs in Southern Ontario, Canada

Dogs are reservoirs for many zoonoses. In southern Ontario, Canada, minimal data exist on the sources from which domestic dogs are acquired (i.e., domestic or imported). The objectives of this study were to (1) describe the proportions of domestically sourced and imported dogs in southern Ontario, Canada, (2) describe the characteristics of newly acquired dogs including their province/country of origin, accompanying health documentation and respondent opinion regarding disease risks from different sources, and (3) determine whether a difference in the proportion of imported dogs exists between rural and urban households in southern Ontario, Canada. We conducted a cross-sectional observational study using an online questionnaire. A total of 2,006 respondents (1,002 rural and 1,004 urban), each representing one household, participated. Over the previous seven-year period, 731 (36.44%, (731/2,006)) respondents domestically sourced at least one dog, with 684 providing information regarding 962 dogs. Domestically sourced dogs were frequently puppies three to five-month-old (25.05%, (241/962)), male (51.87%, (499/962)), from a breeder (30.98%, (298/962)), and sourced from within Ontario (92.93%, (894/962)). As self-reported by respondents, 63.52% (484/762) of domestically sourced dogs greater than 3 months were vaccinated against rabies. Over the same period, individuals from 55 of 2,006 households (2.74%) imported at least one dog. Imported dogs were frequently under three months of age (29.09%, 16/55)), male (58.18%, (32/55)), and found via a breeder (32.73%, (18/55)). Most imported dogs originated from the USA (52.73%, (29/55)). Rabies vaccination in dogs three months and older is provincially required in Ontario and is also required for canine importation into Canada; however, some imported dogs over three months were unvaccinated (7.69%, (3/39)). The odds ratio for importing at least one dog in urban households compared with rural households was 1.93 (95% CI: 1.03-3.62) when controlling for number of household occupants and gross household income.

Automated summary

This study discovered that dogs are potential carriers of many zoonotic diseases. In southern Ontario, Canada, 36.44% of households acquired domestically sourced dogs, mostly from within Ontario. Imported dogs accounted for 2.74%, with most originating from the USA. Urban households were 1.93 times more likely to import dogs compared to rural households.