Cytauxzoon felis is a protozoal organism transmitted to domestic cats by tick bites, and whose natural reservoir host is the bobcat.

[2][3][4][5] C. felis has been found in other wild felid species such as the cougar, as well as a white tiger in captivity.

[citation needed] The first case of C. felis was documented in Missouri in 1976, and in the past it was believed to be limited to south central and southeastern United States.

In studies it is unclear if the sex predilection is due to the increased roaming of intact animals or another reason.

[2] The most common seasons for the disease to become apparent are spring and summer and appear to affect outdoor cats the most often.

Bobcats become persistent carriers of the organism after they develop mild or subclinical infection and then serve as the reservoir host.

[4] Now there have been documented cases of cats that get sick and survive the infection and even those that never show clinical signs at all.

The organism goes through asexual reproduction phase that is called schizogony which occurs in the mononuclear phagocytic cells.

In the tissue phase, the macrophage cells that are infected often clog venules in organs such as the liver, spleen, lungs, and lymph nodes.

[2][11][12] There is not enough information to prove any of these theories, but cats in the same household or same regions can have drastically different clinical presentations.

[4] Because it causes similar signs in outdoor cats during the spring and summer, tularemia is another disease the veterinarian may want to rule out.

[citation needed] The most often used treatments for cytauxzoonosis are imidocarb dipropionate and a combination of atovaquone and azithromycin.

60% of sick cats treated with supportive care and the combination of the anti-malarial drug atovaquone and the antibiotic azithromycin survived infection.