Self-Medication Practices for Companion Animals in Japan: A Descriptive Survey of Pet Owners’ Use of Over-the-Counter Drugs and Perspectives on Pharmaceutical Care

Owner-led self-medication for companion animals is a growing global practice; however, empirical data from Japan remain limited. Framing medication safety within a One Health perspective, this study aimed to characterize Japanese pet owners’ use of over-the-counter (OTC) drugs and identify possibilities for pharmacists to support rational self-medication. A cross-sectional 13-item online survey was administered to 500 owners in Japan between 30 May and 2 June 2025. Data on owner demographics, willingness to consult pharmacists, veterinary visit behavior, and OTC purchasing practices were summarized. Many owners were receptive to pharmacy support; 65% wished to consult a pharmacist, and 6.8% had already done so. Overall, 15.2% reported using OTCs drugs, primarily for treatment or prevention and prioritized perceived effectiveness and safety when selecting products. Some owners managed mild pet illnesses at home, citing perceived mildness and cost as reasons for not visiting a veterinary clinic. There is an unmet demand for accessible expert counseling at the point of purchase. Leveraging community pharmacies linked with pet specialty pharmacies as first-contact hubs could promote appropriate self-medication; doing so would require veterinary-specific training, establishing a formal credential for veterinary pharmacists, and defining pharmacist–veterinarian communication to ensure safe and effective use.