The purpose of using nematophagous fungi as biological control agents of gastrointestinal nematodes of livestock is to reduce the build-up of infective larvae on pasture and thus avoid clinical and subclinical disease. As the interaction of fungus-larval stages takes place in the environment, it is crucial to know how useful the fungal agents are throughout the seasons in areas where livestock graze all year-round. This study was designed to determine the predatory ability of the nematophagous fungus Duddingtonia flagrans against gastrointestinal nematodes of cattle during four experiments set up in different seasons. In each experiment, faeces containing eggs of gastrointestinal nematodes were mixed with 11,000 chlamydospores/g and deposited on pasture plots. A comparison between fungal-added faeces and control faeces without fungus were made with regard to pasture infectivity, larval presence in faecal pats, faecal cultures, faecal pat weight, and temperature inside the faecal mass. In three of the four experiments, Duddingtonia flagrans significantly reduced the population of infective larvae in cultures (68 to 97%), on herbage (80 to 100%), and inside the faecal pats (70 to 95%). The study demonstrated the possibility of counting on a biological control tool throughout most of the year in cattle regions with extensive grazing seasons.

Nematophagous fungi are a biological control tool used against gastrointestinal nematodes in livestock. These fungi prey on free-living larvae in faeces and could be affected by active drugs excreted post-treatment. This study aimed to determine in vitro and under environmental conditions the effect of the following anthelmintics on the fungus Duddingtonia flagrans: ivermectin, levamisole, albendazole, fenbendazole and ricobendazole. The in vitro effect of anthelmintics on fungal growth and predatory capacity was assessed in corn meal agar and coprocultures, respectively. Ivermectin (1, 2 and 10 ppm), fenbendazole (0.027, 0.054 and 1 ppm) and albendazole (1 ppm) significantly affected fungal development. The fungal efficacy against L3 was high in the control and levamisole coprocultures but decreased significantly in the presence of albendazole, fenbendazole, ricobendazole and ivermectin. The impact of levamisole on D. flagrans was further assessed under environmental conditions in autumn and winter; the fungal efficacy measured in faecal pats and the surrounding herbage was not affected by levamisole at any time. This study shows that using albendazole, fenbendazole, ricobendazole or ivermectin may compromise fungal activity, as these drugs affect the free-living stages of nematodes in faeces, but levamisole can be safely considered in parasite control strategies involving D. flagrans and anthelmintic treatments.

Dogs harbour a wide range of endoparasites, many of which pose a significant risk to public health globally due to their zoonotic potential. Addressing the dynamics of zoonotic parasites comprehensively requires epidemiological studies under the One Health paradigm, incorporating multidisciplinary methodologies to explore the complex interactions among humans, animals and the environment. The present study aimed to investigate the presence of canine parasites in public green places (PGPs) in Tandil, Argentina, using epidemiological and geographical tools to enhance efforts towards the prevention and control of canine parasitic diseases impacting public health. Between August 2024 and January 2025, 893 canine faecal samples were collected through a randomised two-stage sampling process from 92 public green places. The overall prevalence of intestinal parasites was 29.9% and the identified parasites were Trichuris vulpis, Ancylostoma caninum, Eucoleus spp., Uncinaria stenocephala, Toxascaris leonina, and Cystoisospora sp. Risk factors identified included the presence of playgrounds and a higher dog density, while protective factors comprised sampling during spring vs. winter and presence of areas of bare soil on the public green places. Spatial analysis revealed clusters of high prevalence in areas with lower socioeconomic status, and clusters of low prevalence in higher socioeconomic areas. These findings emphasise the need for targeted preventive measures, including responsible pet ownership policies. Moreover, the methodological approach adopted could be replicated in other regions to enhance public health protection and mitigate the risks associated with zoonotic parasitic diseases.