Parasitic infection and environmental contamination by endoparasites of dogs on the border between Brazil and Argentina: challenges for public health and biodiversity conservation

Abstract

In developing countries, zoonotic disease outbreaks are often aggravated by complex interactions between ecological, socioeconomic, and demographic factors. In border regions, environmental degradation and social inequalities increase contact between humans and wild animals, intensifying the transmission of zoonotic diseases. This study investigated the prevalence of gastrointestinal parasites in dogs (Canis lupus familiaris) in a rural region near the border between Brazil and Argentina, in the extreme west of the state of Santa Catarina. We analyzed 50 fecal samples collected directly from the soil on rural properties with a high occurrence of stray dogs. The results indicate Ancylostoma spp. as the most prevalent parasite, detected in 82% of the dogs, followed by Trichuris vulpis (30%), Toxocara canis (12%), and Isospora spp. (12%). The statistical analysis revealed significant differences in the infection frequency between the parasite species investigated (χ² = 48.35; p < 0.05). The high prevalence of parasitic infections highlights the importance of integrated public health and veterinary strategies for parasite control and zoonosis prevention. The results reinforce that dogs in rural border areas, especially near large forest areas, are potential reservoirs and sentinels for zoonotic infections. The possible interaction between dogs and wildlife and the complexity of forest landscapes highlights the need for robust epidemiological surveillance and integrated preventive measures. Environmental education programs focused on animal health management and the reduction of direct contact with wild animals are crucial to mitigate the transmission of zoonotic diseases in border regions with high biodiversity and animal mobility.