The word immunity, i.e. preventing epidemic disease, has the same basic meaning in both Traditional Chinese Veterinary Medicine (TCVM) and conventional western medicine. However, theories of how to prevent and treat disease vary between the two medical systems. Each has its own distinctive features, advantages and disadvantages. In TCVM Zheng Qi is the “anti-pathogenic Qi”, which is the body’s power to resist diseases, to adapt and to maintain homeostasis. Xie Qi is “pathogenic Qi”, which includes the various causes of disease. Many of the conventional immunomodulating drugs have negative side effects and may not address the ‘root cause” of the problem. Many Chinese herbs have immunostimulant, immune suppressive and immune-balancing effects, which may be useful alone or in combination with conventional drug therapy to improve the treatment response while reducing the negative side effects. Integrating TCVM and conventional western medicine to treat and prevent diseases and produce a healthier food animal supply may be the best way to ensure optimum human and animal health.