Gastrointestinal helminth infections in cattle and buffalo from small-scale farms in Phayao Province, Northern Thailand.

Gastrointestinal helminth infections remain a major constraint to ruminant health and productivity, particularly in small-scale farming systems where parasite control is often limited. This study investigated the prevalence and distribution of gastrointestinal helminth infections in cattle and buffalo raised in Phayao Province, Thailand. A cross-sectional survey was conducted between August and October 2025, during which 696 fecal samples were collected from cattle and buffalo across six subdistricts and examined using the formalin-ethyl acetate concentration technique. The overall prevalence of infection was 47.8% (333/696), with a higher prevalence observed in cattle (53.8%) than in buffalo (29.7%). Five helminth groups were detected, with strongyle-type nematodes being the most prevalent (28.3%), followed by rumen flukes (11.8%), liver flukes (11.2%), Strongyloides spp. (6.0%), and Trichuris spp. (1.6%). Single infections were more common (37.8%) than mixed infections (10.1%). Analysis of host-associated factors showed no significant association between infection status and age or sex in either host species, whereas cattle breed was significantly associated with infection. These findings indicate a widespread occurrence of gastrointestinal helminth infections among ruminants in the study area and emphasize the need for strengthened parasite control programs and regular monitoring to reduce infection risk and associated production losses.