TCVM is a very holistic approach to health and disease, meaning that the whole animal is taken into account when coming up with a diagnosis. Disease in TCVM is caused by an imbalance between yin and yang, or by invasion of external forces, that are termed "pathogens". Some examples of pathogens in TCVM are wind and cold (note: these are very different than the pathogens that we think of in western medicine, such as bacteria and viruses), and the pathogens invade the body and affect the flow of energy. While acupuncture is the most common form of therapy in TCVM, food can also be used to help bring a patient back into balance. For example, lamb is considered a very warm food in TCVM, so this would be a good choice of protein to feed a patient that has been invaded by "cold"; and many patients with food allergies have excess "heat" in their bodies (evident the red, warm skin), so these patients would benefit from being fed cooling foods, such as rabbit or duck. It is worthy to note, that while many kibbles contain these various types of protein, the more a food is processed, the more vital energy or "Qi" it loses, so TCVM food therapy often involves feeding fresh whole foods (raw or slow cooked), either formulated into a complete diet or added to commercial diets.