Document Type


Subject Area(s)

Anti-Bacterial Agents (administration & dosage); Cross-Sectional Studies; Drug Misuse (statistics & numerical data); Humans; Nonprescription Drugs (administration & dosage); Patient Medication Knowledge; Pharmaceutical Services, Online (statistics & numerical data); Search Engine (statistics & numerical data); Self Medication (statistics & numerical data); United States; Veterinary Drugs (administration & dosage)


Self-medication and antibiotic utilization without healthcare oversight may lead to delayed appropriate treatment, transmission of communicable infections, untoward adverse events, and contribute to antimicrobial resistance. Previous data suggest people obtain over-the-counter (OTC) animal antibiotics for their personal use. This study examined the availability of OTC fish antibiotics online and the documented intent for self-medication. The authors conducted a web-based cross-sectional study using Google search engine to identify vendor websites selling fish antibiotics in the United States. Vendor websites were included if product information, consumer reviews, and comments were publicly available. Nine fish antibiotics were chosen due to their possibility of having consequences to human misuse. The cost and availability of fish antibiotics was recorded. The proportion of reviews and comments related to human consumption was calculated. Consumer review traffic based on "likes" and "dislikes" received was compared between human- and non-human consumption-related reviews. Selected fish antibiotics were purchased and evaluated for physical appearance and compared to FDA-approved available equivalents. We found 24 website vendors with online ordering available for OTC fish antibiotics. Cost varied significantly by antibiotic and quantity ranging from USD $8.99 to $119.99. There were 2,288 reviews documented for the 9 selected antibiotics being sold. Among consumer reviews, 2.4% were potentially associated with human consumption. Human consumption-related reviews constituted 30.2% of all "likes" received and 37.5% of all "dislikes" received. Human consumption-related reviews received an average of 9.2 likes compared to 0.52 likes for non-human consumption-related reviews. The 8 fish antibiotics purchased were consistent with FDA-approved equivalents in physical appearance. Although infrequent, antibiotics intended for fish use are being purchased online without a prescription for self-medication to circumvent professional medical care. Reviews related to human consumption generate significant online traffic compared to reviews unrelated to human consumption.

Digital Object Identifier (DOI)

APA Citation

Zhang, W., Williams, A., Griffith, N., Gaskins, J., & Bookstaver, P. (2020). Online availability of fish antibiotics and documented intent for self-medication. PLOS ONE, 15(9), e0238538.