Haemotropic mycoplasmosis in cats: current aspects regarding prevalence, clinical signs, diagnosis, therapy and prognosis

Feline haemotropic mycoplasmosis (haemoplasmosis) is caused by the species Mycoplasma haemofelis (Mhf), Candidatus Mycoplasma haemominutum (CMhm), and Candidatus Mycoplasma turicensis (CMt). The route of transmission has not been confirmed, but fleas and other arthropods are probably involved. Important factors determining the course of the disease include the host's immune system and the haemoplasma species. Haemoplasms attach to the erythrocyte surface and induce haemolysis. Most cats that recover from an acute infection become lifelong carriers after sequestration of the organism in different tissues (especially the liver and spleen). Mhf has the lowest tendency for sequestration and is the most pathogenic species, followed by CMt and CMhm. PCR testing is the test of choice for diagnosing haemoplasma infections. Serology is not routinely performed, but might be useful to differentiate an acute from a carrier status. In most cases, antibiotic treatment (doxycycline, fluoroquinolones) for 14 days lowers the blood organism load. Depending on the clinical signs, supportive care (e.g. blood transfusions) may be required. An infection may reactivate after many months to years in the presence of immunocompromisation or a concurrent disease. Treatment rarely eliminates the haemoplasms completely.