Currently, traditional ethnoveterinary practices are rare in European Union countries and the herbal remedies used previously have been mainly replaced by the modern drugs promoted by national veterinary services. However, in some rural areas of the Mediterranean basin, these traditional practices persist. Here we present the vascular plant resources still used, or that have been used until the last decades, in the health care and comfort of domestic animals in Spain. The veterinary use of 711 plant species, belonging to 108 botanical families, has been documented in the development and implementation of the Spanish Inventory of Traditional Knowledge (IECT). We present a series of examples of the great diversity of remedies traditionally used in the treatment and/or prevention of many diseases or conditions of domestic animals, and we also discuss the importance of several plants used as fodder or bedding for livestock. In the context of current European agricultural policies, this biocultural heritage could constitute a fundamental step for the discovery and isolation of natural extracts from plants in the search for new and low-cost drugs, promoting the use of phytotherapeutic products, and favouring a cultural change and a mentality oriented to new ways of understanding extensive farms, transhumance and the relationship with the animal world, consistent with prophylactic veterinary medicine.