Fasciola hepatica in alpine dairy farming: prevalence trends, risk factors and associations with Salmonella Dublin seropositivity.

Abstract

UNLABELLED: impairs animal health and productivity in ruminants and has been associated withDublin infection, a zoonotic pathogen in cattle that causes diarrhea, abortions, and pneumonia. This work reassessedseroprevalence in Tyrolean dairy herds and investigated associations with alpine pasturing, the breed,Dublin occurrence and milk performance. In late autumn/early winter 2023, bulk tank milk samples from 3645 farms were tested using a commercial ELISA test (IDEXX Fasciolosis Verification Test, Montpellier, France). Binary logistic regression and linear mixed models were used to evaluate risk factors and production effects. Overall, 86.1% of herds were positive forantibodies - an increase of 13.1% compared to 2005. Alpine pasturing was a significant risk factor (odds ratio [OR] 4.7), andDublin-positive farms had higher odds of-infection (OR = 9.0). In non-alpine grazing herds, all models showed that-infection was significantly associated with reduced milk yield, while no such associations were observed in the population with alpine pasture management. However, breed-specific analysis among alpine-pastured cows showed significant negative associations on milk yield in Simmental ( = 0.041) and Brown Swiss ( = 0.039). These results reveal an increasingprevalence in Tyrol and highlight alpine pasturing as a major risk factor. The observed production losses and the strong link withDublin emphasize the parasite`s broader economic and public health importance for dairy farms in the European Alps. From a practical perspective, there is a clear need for region-specificcontrol strategies in alpine dairy systems, with particular focus on pasture management and herd-level surveillance. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12917-026-05383-1.