This study aimed to describe and compare the role of veterinarians and feed-store vendors in the use of antibiotics on small dairy farms in Cajamarca, Peru, a major dairy-producing center characterized by small, rural farms with poor, mostly uneducated farmers. We used a purposive sampling strategy to recruit 12 veterinarians into 2 focus group discussions and supplemented these data with 8 semi-structured interviews with feed-store vendors. Participants reported that inappropriate antibiotic usage was widespread among their clients, which may prevent the efficient use of drugs on farms where animal disease can be devastating to the livelihood of the farmer. Participants also identified many barriers to appropriate prescribing and use, including availability of drugs, competition from other prescribers, economic constraints and habits of farmers, and limited farmer knowledge of drugs and disease. Veterinarians expressed mistrust toward nonprofessional prescribers, whereas feed-store vendors felt that veterinarians were important partners in promoting the health of their clients' animals. © 2013 American Dairy Science Association.