Infrared thermography is a non-invasive imaging diagnostic modality used in veterinary medicine as a screening tool, especially in cases of musculoskeletal and neurological diseases. The infrared camera is able to measure the body's surface heat and produce a map with different shades of colors that represent the distribution of heat in the body. During the acquisition of images, it is important to consider several factors in the examination, such as the model of the equipment, pixel capacity, environmental and biological factors for each species to be analyzed. It is a complementary diagnostic tool of wide use in the most diverse specialties and conditions in veterinary medicine, such as oncological, dermatological, reproductive, ophthalmological, neurological, musculoskeletal, metabolic patterns, pre, trans and postoperative, in addition to being an important non-invasive complementary test for the evaluation of animal welfare. This review discusses the fundamentals of the technique, its main uses and applications, and the role of thermography as a complementary tool for diagnosis and follow-up of therapeutic evolution in veterinary medicine.