Feline cytauxzoonosis

Abstract

Cytauxzoon felis is a protozoan hemoparasite of wild and domestic cats. In domestic cats, it causes severe clinical disease with high mortality.

Neuropathology of Natural Cytauxzoon felis Infection in Domestic Cats

“…17 The antemortem diagnosis of cytauxzoonosis can be suspected on the basis of clinical signs and confirmed by the detection of parasitized erythrocytes on peripheral blood smears, but this method has not been regarded as sensitive, since piroplasms may be absent in up to 50% of samples. 4,17 Thus, infection may be also confirmed by detection of circulating schizont-laden macrophages on blood smears or by polymerase chain reaction. 4 Postmortem diagnosis is usually based on the pathologic changes and identification of intravascular schizont-laden macrophages.…”

“…2,3,8,9,11,12,16,17,23 While the erythrocytic phase of infection is typically associated with anemia, the macrophagic phase leads to systemic circulatory compromise due to partial or complete vascular obstruction by schizont-laden macrophages. 17 Affected cats may have subclinical infection or develop acute, systemic, frequently fatal disease characterized by a range of clinical signs, including anorexia, dehydration, depression, fever, icterus, anemia, and dyspnea. 1 Common gross pathologic changes consist of icterus, pulmonary hemorrhages, splenomegaly, lymphadenomegaly, and disseminated hemorrhages in multiple organs.…”

“…Swollen schizont-laden macrophages have been regarded as a substantial mechanism of vascular occlusion and impaired blood flow in multiple organs during C. felis infection in cats. 17,23 Death has been attributed to shock with respiratory failure due to decreased pulmonary perfusion and gas exchange from vascular obstruction and interstitial pneumonia. 4,21 Furthermore, the marked systemic inflammatory response in these cases is thought to be important in the pathogenesis of the disease.…”

“…1 Common gross pathologic changes consist of icterus, pulmonary hemorrhages, splenomegaly, lymphadenomegaly, and disseminated hemorrhages in multiple organs. 2,4,11,17 Major histologic changes include the presence of swollen schizont-laden macrophages that adhere to the vascular endothelial surface and partially or completely occlude the lumen of blood vessels.…”

“…1,2,4,8,9,11,12,17,21 Five had a suspected diagnosis of C. felis infection before death that was based on the clinical signs. Swollen schizont-laden macrophages have been regarded as a substantial mechanism of vascular occlusion and impaired blood flow in multiple organs during C. felis infection in cats.…”