Although M. haemofelis is generally the least prevalent of the three known feline Haemoplasmas, it causes the majority of FIA cases in the United States. Blood-sucking Arthropod vectors including fleas, mosquitoes, and ticks are thought to be the primary mode of dissemination of M. haemofelis.[1] Transmission from queen to kitten has also been observed, however it is unclear if this takes place in utero, during birth, or through nursing.