Dog and cat populations in rural, remote, and Indigenous communities have special issues regarding parasite fauna and management of parasites. While there are pets that live in the home and receive commercial pet food, others are free-roaming and may be exposed to a wide range of parasites transmitted through consumption of wildlife, fish, and scavenging human food waste. Helminth eggs rarely reported in urban dogs and cats are not uncommon in fecal flotations from dogs and cats in rural and remote regions, including taeniid-type eggs (Taenia or Echinococcus) spp. (from consumption of larval tapeworms in meat or organs of prey species such as cervids, rodents, and rabbits), Diphyllobothrium spp. (from consuming larval tapeworms in fish) and trematodes transmitted via consumption of aquatic vertebrates, such as Alaria spp. (frogs and other small paratenic hosts) and Metorchis conjunctus (suckerfish). There may also be dietary artifacts from consuming parasites shed in the feces of wildlife hosts. For example, dogs (and, rarely, cats) can shed eggs of Baylisascaris spp., for which they may serve as true definitive hosts (with adult nematodes in the intestine) or mechanical transport hosts (from consuming raccoon, bear, skunk or wolverine feces). For protozoans, it is not uncommon to find sporocysts of Sarcocystis spp. (from consumption of sarcocysts in bird and mammal intermediate hosts), Cryptosporidium spp. oocysts, and Giardia spp. cysts in feces of dogs in rural and remote regions. High prevalence of zoonotic genotypes (A and B) of Giardia have been reported in free-ranging dogs in northwestern Canada, in contrast with pet and kennel dog populations elsewhere (dominated by dog specific genotypes C and D). As well, dogs and cats in rural and remote regions may frequently harbor wildlife ectoparasites, such as fleas (Pulex simulans), or ticks such as Ixodes cookei, I. kingi, and Haemaphysalis leporispalustris. These should not be confused with significant veterinary and human ectoparasites such as Ctenocephalides spp., Pulex irritans, or Ixodes scapularis. However, rural and remote dogs are often excellent sentinels of vector borne diseases (such as Lyme disease, tularemia, or plague) because they are often outdoors, share their environments with wildlife, and may not be examined or treated as frequently as urban pets.
Because many rural and remote communities and owners are unable to access or afford veterinary services on a regular basis, many pets are not routinely tested or dewormed and there may be high prevalence and intensity of “normal” nematode fauna such as Toxocara spp., Toxascaris leonina, and Uncinaria stenocephala, especially in young animals. However, surveillance in dogs and wild canids suggests that Toxocara canis is rare at latitudes north of 60°N, which may reflect freeze susceptibility of the eggs; further work is needed to better define the geographic distribution and bioclimatic limits of this important zoonosis, especially in light of rapidly warming climate in northwestern Canada. It is important to note that dogs and cats can be sources of human exposure to zoonotic parasites such as Echinococcus, Baylisascaris, Toxocara, Toxoplasma, Giardia, and Cryptosporidium. However, pets themselves are not usually the direct source of infection for people, who are infected through shared contaminated environments, or, for Giardia and Cryptosporidium, from other infected people. As well, pets may serve as sentinels of circulating zoonoses such as Diphyllobothrium, Alaria, and Metorchis, infected by the same foodborne routes as people, but not a direct source of human infection. It is important to note that country foods (hunted game or fish) are healthy, nutritious and economical, and with appropriate preparation – e.g., cooking or freezing – need not increase exposure to parasites.
Special considerations for management of parasites in dogs and cats in remote, rural, and Indigenous communities include recognition of the need for better delivery of veterinary services to such regions, building local capacity to manage free-ranging pet populations (which may include surgical or other methods of sterilization, bylaws, etc), and supporting culturally sensitive wellness and education initiatives to improve animal and human health. There is an urgent need to coordinate, document, and critically evaluate the commendable efforts of a wide range of Non-Governmental Organizations, veterinary colleges, veterinary practices, and community groups involved in such work across Canada, as well as regulatory efforts to allow veterinary “Telehealth” and paraprofessionals to offer local wellness services in rural and remote regions. Also critically needed are programs to engage community members in the planning/execution/implementation of interventions, to build long term sustainable solutions. Until then, many of these animals will end up entering shelters or rescue organizations. Animals from a rescue or shelter in northern and western Canada should be screened and treated for the wider range of parasites that they may harbor, such as Echinococcus canadensis, which has been reported in shelter dogs in Canada.