Smallholder Mexican farmers are embedded in an adverse context, due to neoliberal globalization policies, which threatens their livelihoods, and has caused an unprecedented surge of migration to the US. Keeping goats is one strategy to diversify livelihoods. Goat husbandry is dairy oriented and has a range of functions for farmers, like income, food, insurance, credit, and a reason for not having to migrate to the US. However, caprine brucellosis, a zoonosis endemic in Mexico caused by Brucella melitensis, has a negative impact on flock productivity. Although brucellosis is rarely a fatal disease in humans, it can be very debilitating and disabling due to complications such as arthritis and spondylitis. The main objectives of this thesis were to assess the impact of brucellosis on smallholder goat husbandry and to evaluate brucellosis control strategies in enhancing farmers' livelihoods. The research approach was that of a case study, incorporating methods from natural and social sciences, such as archival and secondary data review, surveys, ethnography and veterinary epidemiological modelling. The case study was conducted in two states within the Bajío region with high rates of migration: Michoacán and Jalisco. In Michoacán free cost vaccination and testing was applied whereas in Jalisco farmers had to bear part of those costs and there was a lack of veterinarians offering the service. Goat farmers considered that they were better off than farmers who did not keep goats: 'it is better to herd than to be herded'. Farmers' knowledge, labour and good social capital allowed them to maintain relatively large flocks given the amount of crop land owned. The prevalence of testing positive to brucellosis in goats was 38% in Jalisco and 11% in Michoacán. Access to communal land and crop residues were key for the pastoral management system prevalent in the study area, but grazing goats had higher risk of testing positive to brucellosis. Farmers avoided drinking goat milk, as it was seen as a cause of 'fever'. The milk price was low and controlled by the caramel industry. Vaccination and test-and-cull strategies are options to control brucellosis. Simulations showed that vaccination is economically feasible but will not bring the prevalence below to 10% within 5-years. Test-and-slaughter is not economically rewarding at the current milk price. At present, culling of seropositive goats to brucellosis does not happen because an adequate infrastructure for culling does not exist. Farmers perceived that brucellosis control measures cause losses such as abortion due to untimely vaccination and infections due to ear tagging. Moreover, farmers did not always know that brucellosis and Malta fever (human brucellosis) are synonyms, neither were they aware of all consequences of brucellosis infection. Brucellosis control is stagnant because of a two way lack of communication: farmers are not well informed about brucellosis and policies are formulated without knowledge of goat farming practices and of farmers' perceptions. Successful brucellosis control would enhance smallholder goat farmers' livelihoods but the control policy needs to be redesigned. Important factors to consider in the design of a new policy are: (1) a comprehensive compensation for losses when applying test-and-cull; (2) the integration of farmers' expertise and experience; (3) diffusion of knowledge about brucellosis control, its prevention and its impact on human health and livestock production; (4) a regional planning is a must to succeed.