Anaplasma phagocytophilum is an intracellular bacteria that causes several non-specific
symptoms (for instance, horse lying down), posing problems in differential diagnosis. Usually, symptoms appear few days after tick exposure.
The exact mechanism by which A. phagocytophilum induces rhabdomyolysis is unknown. Interferon g has been shown to be critical for the induction of histopathologic changes in mice, even in the absence of substantial bacterial load and despite its ability to avoid killing by innate immunity, A. phagocytophilum paradoxically induces some innate responses that have been documented to contribute to tissue injury.