A review of recent developments in essential oil-based alternatives in mastitis treatment in dairy cows

Mastitis remains a major challenge in dairy production due to economic impacts, decreased milk yield and quality, increased veterinary expenses, and the contribution to antimicrobial resistance through conventional antibiotic use. This narrative review with a structured literature search explores the potential of essential oils as alternative therapeutic agents against bovine mastitis. A comprehensive search of Web of Science and Scopus databases (2008–2024) yielded 71 eligible studies, of which 61 were in vitro, six in vivo, and four combined approaches. The majority of in vitro studies reported strong antibacterial effects of essential oils against major mastitis-causing pathogens, including Staphylococcus aureus, Escherichia coli, and Streptococcus agalactiae. In vivo studies, although limited in number, showed encouraging outcomes in terms of reduced somatic cell count and clinical improvement, but lacked consistency in dosage, formulation, and treatment duration. Commonly tested essential oils included Thymus vulgaris, Origanum vulgare, and Melaleuca alternifolia, often demonstrating minimum inhibitory concentrations ranging from 0.25 to 2.5%. Key limitations of the study include variability in essential oil composition, absence of standardized testing protocols, and insufficient clinical validation. Essential oils show promising antibacterial activity in vitro and potential for mastitis control in vivo, but clinical application is still limited by regulatory, methodological, and formulation challenges. Future studies should focus on standardizing preparations and conducting robust, large-scale in vivo trials to establish safety, efficacy, and practical application in dairy herds.