The medicinal use of plants for animal health purposes is a tradition found worldwide. Nowadays, the idea of using the medicinal properties of plants in animals may be focused on two different perspectives: (1) the increasing concern with environmental issues and the growing popularity of organic farming as means of diminishing impacts on environment and public health; and (2) the need to find low cost solutions that allow the development of food production and cattle raising in underdeveloped countries. The present work aims to survey traditional medicinal uses of plants in animal health, namely on Equidae, in the Alentejo region, south Portugal. Being the first study regarding this subject, our first concern was to review ethnoveterinary studies in regions that presented similar soil and weather conditions, as well as common cultural background. A preliminary survey was carried out in Alentejo, during 2011 and the beginning of 2012. Forty semi-structured interviews were carried out with local individuals, mainly farmers, animal breeders and animal handlers, scattered throughout Alentejo. Data on plant taxa, medicinal uses and preparations for the different domestic animal groups (Bovinae, Caprinae – Capra, Caprinae – Ovis, Equidae, Suidae, Galliformes, Canidae and Felidae) were collected. Additionally, human utilization of medicinal plants was registered. A total of 626 citations of plant/application/animal or human were collected. The animal citations correspond to 75% of total. Among these, 19% mentioned the medicinal use of plants in Equidae (horses, donkeys and mules). The most frequently mentioned plants for Equidae were mallow (Malva spp./Lavatera spp.) and wooly St. John’s wort (Hypericum tomentosum). The most frequently mentioned use was the treatment of trauma, followed by gastrointestinal conditions. These results agree with those referred by other authors of ethnoveterinary studies in Mediterranean countries. Further studies should therefore be conducted, to allow common knowledge registration and problem resolution in Mediterranean areas, and to scientifically test the pharmacological application of these plants.