Humans have been domesticating animals for milk and food or keeping them as pets since their evolution on the planet. Animals have become an intrinsic part of human lives, contributing to their growth and advancement. In recent years, rapid growth in various industrial sectors has led to the depletion of natural resources and climate change, resulting in the development of many diseases in animals. This poses a major threat to farmers and reduces livestock productivity. Notably, more than 60% of human diseases originate from animals. To meet the increasing demand for food sufficiency due to the constant increase in world population, it is crucial to incorporate advanced computational techniques to rapidly develop new veterinary medicines for livestock health and welfare, ensuring food security. Vetinformatics emerges as a new scientific approach that combines bioinformatics resources with veterinary science to transform animal welfare, involving the systematic study of operations of complex molecules in animal systems. This chapter underscores the role of quantitative structure–activity relationship (QSAR) studies predicting the biological activity of various compounds as veterinary drugs to enhance the well-being of animals against diseases. Additionally, the accumulation of residual veterinary drugs and the application of QSAR approaches to predict the ecotoxicity of these drugs in the environment are discussed.