Abstract: Infectious diseases caused by Ehrlichia canis (E.canis) have a serious threat to the health of dogs or human.E.canis can invade the body through wounds on the skin surface or bites of arthropods,triggering a series of reactions in the body and leading to E.canis-related diseases.In addition,the clinical symptoms of diseases caused by E.canis are similar to other diseases,which brings difficulties in ways of rapid diagnosis.E.canis is a strict intracellular parasitic pathogen,and is negative stained by Gram staining and is purple stained by Gimsa staining.It is possible to isolate this pathogen successfully and realize culture in vitro.E.canis is able to induce autophagy of host cells,remaining their own survival and proliferation through capturing nutrients from the host,and can induce the body to have an immune responses.Through producing a large number of inflammatory factors,E.canis causes fever and brings damage to tissues and organs.E.canis has a special mechanism of immune escape to avoid being eliminated by lysosomes or other immune factors of hosts.E.canis can grow and reproduce in macrophages and destroy the anti-inflammatory factors in the host cell in order to destroy the host immune function.However,how E.canis capturing or destroying nutrients and survival of hosts remains unclear,and evading the 'tracking’ of immune system of hosts are still further investigated.In terms of treatment,E.canis related diseases are only sensitive to some antibiotics such as doxycycline.However,the best way to prevent this disease is to remove regularly ectoparasite.Consequently,the aim of the article is to summarize the pathogenesis,epidemiology and pathogenic mechanism of E.canis,including advanced research status between partial pathogens and host cells.

Key words: canis; Ehrlichia canis; monocyte-macrophage; pathogenic mechanism