Simple Summary
The small freshwater snail Galba truncatula spreads parasites that harm livestock and wildlife, but data on its distribution and habitat preferences in Southeastern Europe are scarce. This study covers 191 water points in Bulgaria, focusing on animal-watering fountains, to map where the snail lives and to explore how factors as altitude, temperature, precipitation, shade and type of water body affect its occurrence. A logistic regression model was constructed to assess the importance of environmental factors in the occurrence of snail species. G. truncatula was found at 56 locations (29.3%), including in regions where it had never been recorded before. Preferred habitats were streams (60%) and banks on small rivers (50%), but presence in artificial fountains was up to 24%. Temperature, shade and type of water body were identified as important factors, determining the occurrence of G. truncatula. The results show that G. truncatula can adapt to many habitats, including those frequented by domestic animals, which increases the risk of parasite transmission. Mapping its spread helps predict and manage diseases such as liver and rumen fluke infections in livestock, supporting better animal health, reduced economic losses for farmers, and improved protection of wildlife in Bulgaria and the wider region.
Abstract
Galba truncatula acts as an intermediate host for several parasitic flukes of veterinary importance, but a targeted study on its spatial presence as well as the impact of environmental factors in Southeastern Europe has not been conducted. During the summer months of 2017 and 2018, a survey of 191 water bodies in 14 districts in Central, Southern and Western Bulgaria was conducted, with a focus on animal drinking fountains. Each site was assessed for snail presence and characterized by altitude, temperature, precipitation, shade and type of water body. Logistic regression modeling was used to identify the important factors related to the occurrence of snail species. The frequency of habitats found was 29.3%, with no differences observed between the studied districts (p > 0.05). Snails were present across a wide range of altitudes (78–1926 m), annual mean temperature (7.8–14.0 °C) and annual mean precipitation (523–796 mm). The high habitat frequencies were recorded in streams (60.0%) and on the banks on small rivers (50.0%). The presence of snails in the two studied types of fountains (without or with a concrete platform) was 24.1% and 17.2%, respectively, with no significant difference between them (p > 0.05). Regression analysis revealed temperature, shade, and type of water body as factors that could significantly influence the spatial presence of G. truncatula. The findings demonstrate the ecological adaptability of G. truncatula and highlight its presence in habitats with high potential for contact with domestic and wild ruminants. This information fills a regional knowledge gap and can support risk assessment and control measures for fluke-borne diseases in livestock and wildlife.