Which stage of Cytauxzoon felis is associated with vascular obstruction?

The stage of Cytauxzoon felis associated with vascular obstruction is the schizont stage, which is found in macrophages. During this stage, the parasite undergoes a process of asexual reproduction, leading to the formation of numerous schizonts within the macrophages. As the infection progresses, these schizonts can cause significant cellular damage and inflammation, which can result in vascular obstruction.

This obstruction arises because the infected macrophages can infiltrate the blood vessels, leading to blockage and reduced blood flow. This phenomenon is significant in the clinical manifestations of Cytauxzoon felis infection, as it contributes to the severe clinical signs observed in affected cats, including lethargy, fever, and potential organ dysfunction due to impaired blood circulation.

Other stages of the parasite, such as tachyzoites, oocysts, and sporozoites, have different roles in the life cycle and pathogenicity of Cytauxzoon felis. For instance, tachyzoites are responsible for infecting red blood cells, but they do not cause vascular obstruction in the same manner as schizonts. Oocysts are environmental stages that do not interact with the host's vascular system, and sporozoites are the initial infective forms that enter the host through the