Ethnoveterinary medicinal plants in Aseko District, Arsi Zone, southeastern Ethiopia.

Ethnoveterinary medicine remains a key component of livestock healthcare in rural Ethiopia, particularly in areas with limited access to modern veterinary services. This study documented ethnoveterinary medicinal plants, associated indigenous knowledge systems, and conservation challenges in Aseko District, Arsi Zone, southeastern Ethiopia, using a bilingual (English-Afaan Oromo) disease classification framework to improve diagnostic clarity and strengthen veterinary relevance. Data were collected from 182 informants across seven purposively selected kebeles representing highland, midland, and lowland agroecological zones. Semi-structured interviews, focus group discussions, guided field walks, preference ranking, direct matrix ranking, and local market surveys were employed following established ethnobotanical methods. Voucher specimens were collected, taxonomically authenticated, and deposited at the Ethiopian Biodiversity Institute (EBI) National Herbarium. A total of 66 ethnoveterinary medicinal plant species belonging to 49 families were documented. Herbs constituted the dominant growth form (42.4%), and most remedies were prepared from fresh plant materials harvested from wild habitats (66.7%). Leaves were the most frequently used plant part (46.5%), followed by roots and bark, while oral administration was the predominant route (67.5%). Gastrointestinal disorders, ecto-/endoparasitic infections, and dermatological diseases together accounted for 68.2% of total use reports. Informant Consensus Factor values ranged from 0.25 to 0.67, with the highest agreement observed for reproductive disorders, indicating relatively strong consensus among informants for specific ailment categories. Preference ranking identified Hagenia abyssinica, Zingiber officinale, and Embelia schimperi as the most preferred species for treating livestock diarrhoea. Despite high plant diversity, dependence on wild habitats combined with agricultural expansion and biomass extraction was identified as a major threat to long-term resource sustainability. The study demonstrates both the resilience and vulnerability of ethnoveterinary knowledge in a biodiverse but increasingly pressured landscape. Strengthening community-based conservation, systematic documentation of indigenous knowledge, and integration of validated ethnoveterinary practices into local livestock healthcare systems are strongly recommended.