Free-roaming dogs (Canis lupus familiaris) and cats (Felis catus) have a myriad of impacts on ecosystems around the world through predation, competition with native species, and spreading disease. Domestic dogs for example have been cited in a number of studies for transmitting canine parvovirus to native sympatric carnivores, and domestic cats have been responsible for Toxoplasma gondii infection in native, endangered wildlife worldwide. Additionally, zoonotic diseases from these animals, such as rabies, have the potential to impact human health. Given the dual lifestyle of free-roaming cats and dogs, where they interact both with humans and sympatric ecosystems, it is unclear whether parasitic infection would be more influenced by human-mediated socioeconomic factors, or ecological ones. To answer this question, we conducted a meta-analysis using parasite prevalence in dogs (313 studies) and cats (91 studies) to assess parasite prevalence in association with gross domestic product (GDP) , gini index (measure of income disparity), NBI (national biodiversity index) and latitude.
Results/Conclusions:
We find that parasite prevalence in dogs is significantly negatively associated with GDP and positively associated with income disparity for both zoonotic and non-zoonotic parasites. In cats, only zoonotic parasites are significantly negatively associated with GDP with no significant association for GDP of non-zoonotic parasites or GINI index. For parasite prevalence in both cats and dogs, there were no significant associations with NBI or latitude. These findings are the first to suggest that economic factors influence prevalence of parasites not only in humans, but their animal companions as well. Given that free-roaming cats and dogs are known to spread parasites, factors like income disparity and the GDP of a country has the potential to impact the health of wildlife as a result of transmission by domestic carnivores and is another example of the far-reaching impact humans can have on sympatric ecosystems.