qualifications. In ourstudy twoagencies level-1 wererunbyveterinarians that haveadoctorate in veterinary medicine and two were run by veterinary technicians. A third level was occasionally reported by participants, but as it differed betweeninterviews, it wasnot included in the figure. Private veterinarians in Vietnam are stakeholders called veterinarians by other participants or themselves, with a university, college degree, or without any degree but with someexperiences in veterinary medicine. The end users were identified as three types of farms with different input and output sources: integrated farms (contracts with integrators), family commercial farms (private farms), and household farms (backyard farms). VietGAHP (Vietnamese Good Animal Husbandry Practices) farms were certified under the same-named standards. We defined veterinarians as veterinarians who worked for an agency or independently that provided farmers with direct advice and drugs. Company veterinarians or technicians were stakeholders employed by a company (pharmaceutical, feed, alternative feed, or integrator) with a university degree in veterinary medicine or college degree in a technique (veterinary technician, feed technician, …) . Their roles are described in Supplementary Material 3. Interactions among the identified stakeholders varied. The agencies charge a fee for drugs, feed, and materials, but they also offer advice to farmers. These interactions can be facilitated through a contract between farmers, agencies, and distributors. In this case, these agencies receive preferential pricing and benefits if they purchase or sell a certain number of drugs. The interactions can also take place across a network of farms, in which a technician employed by an integrator provides the farm with drugs and advice. This chain is regulated by authorities at various territorial levels, as shown in Figure 2. The Department of Animal Health (DAH) regulates antibiotic importation, production, and distribution, as well as medicated feed mills. The department is also responsible for delivering practice certificates to veterinarians. The Department of Livestock Production (DLP) regulates feed companies.TheDAHoverseestheprovincialSub-DepartmentofAnimalHealth(Sub-DAH), which merged with the Sub-Department of Livestock Production (Sub-DLP) to form the Sub- Department of Animal Health and Livestock Production (Sub-DAHLP). The DAH provide Sub- DAHLPwithinformation and guidelines for implementing legislation. In exchange, they receive reports on the situation in each province. The two last administrative levels are veterinary district stations and communal veterinarians, which operate on the district and communal levels, respectively. In Vietnam, communal veterinarians are stakeholders mandated by the government and are responsible for the sanitary situation, disease control and vaccination campaign. Of the two communal veterinarians interviewed, one did not hold a university or college degreeinveterinary medicine.They bothhad aside-job: private veterinarian or working in another field. Finally, international organizations, international collaborators, and national and foreign research centers work together with government authorities to provide evidence for the development of new policies and technical guidance.