Antibiotic usage and the associated factors in the aquaculture farms of South-West Region of India

The fast-growing aquaculture industry has increased worldwide use of antibiotics, which lead to a global emergence of antimicrobial resistance, posing serious threats to aquatic life, humans, and the environment. This study aimed to investigate the patterns of antibiotic usage in both edible and ornamental fish farms in Kerala, a state in India, and the factors affecting these practices such as farming experience, training, education, disease prevalence, and expert recommendations for disease treatment. A cross-sectional spatial survey was conducted among 188 edible and ornamental fish farms across the state through structured questionnaires targeting antibiotic usage practices and associated risk factors. It was identified that farmers lack sufficient knowledge about aquatic pathogens, diagnostic methods, antimicrobial usage, dosages, and pharmacokinetics. Antibiotic use in ornamental fish farms was significantly higher (25.4%) than in edible fish farms. Tetracycline was found to be the most common antibiotic used in both the edible (4.3%) and ornamental (14.8%) fish farms and was most prevalent in the Central (55%) and Southern (30%) regions of Kerala, with lower usage in the Northern region (15%) likely due to fewer farming operations and lower urbanization. Moreover, the main risk factors influencing antibiotic usage were frequent disease outbreaks, lack of access to trained professionals, reliance on peer advice, over-the-counter antibiotic availability, and absence of strict regulations. The study recommends the development of an effective strategy that will minimize the use of antibiotics and the risks they pose and to promote better farming practices that will improve fish health. These findings can support the development of policies that will regulate antibiotic usage and curb antimicrobial resistance in aquaculture systems. • A survey was conducted on antibiotic usage in fish farms across Kerala. • Commonly used antibiotics: Tetracycline, Metrogyl, and Oxytetracycline. • Central Kerala recorded the highest levels of antibiotic application. • Ornamental farms used 25.4% more antibiotics compared to edible fish farms. • Key drivers: frequent disease outbreaks, lack of training, and limited experience.