C-reactive protein (CRP) is an acute protein synthesized by liver cells in time after the animal body is stimulated by inflammation such as pathogenic microorganism infection or body tissue damage. The CRP content in normal dog and cat serum is extremely low, basically less than 10mg/L. Different types of diseases have different changes in CRP. Canine CRP is highly sensitive to diseases and can rise rapidly in the early stages of the disease to reflect the condition in time. Moreover, the concentration of CRP is not affected by antibiotics and immunosuppressants, and the development of the disease can be accurately monitored during treatment, so it has high value in clinical diagnosis and treatment.