Impression smears of affected tissues are usually diagnostic. Despite the severity of infection, very few signs of inflammation are evident histologically. Large macrophage with innumerable Cytauxzoon felis merozoites . View of hepatic parenchyma demonstrating macrophages with schizonts of Cytauxzoon felis. Closer view of hepatic blood vessel showing partial blockage of lumen by parasite-laden macrophages.
Schizogony is present within macrophages in the splenic parenchyma.
Historically, diagnosis with cytauxzoonosis has a very poor prognosis. A current study has suggested that treatment with certain antiprotozal drugs may control or eliminate cytauxzoonosis in cats. This small clinical study suggests that effective treatment may be possible for a disease that has been refractory to treatment for decades. In previous decades, most cases of cytauxzoonosis occurred in the Brunswick, Georgia area. More recently, cats with the disease have been observed within the greater Atlanta metropolitan area.