Super-Cali-Fragilistic Cytauxzoonosis

The sound of the word Cytauxzoonosis (pronounced Sight-Oh-zO-un-Osis) is not the only atrocious thing about it, as more North Carolina cat owners are discovering. That’s because this tick-borne illness, if untreated, can be fatal to cats.

Cytauxzoonosis is related to malaria and is caused by the parasite Cytauxzoon felis (C. felis), which is found in ticks carried by host bobcats. According to Dr. Adam Birkenheuer, associate professor of internal medicine at NC State, C. felis was first discovered in Missouri in the mid-1970s and for years was only documented in the south central region of the United States. Prior to the late 1990s, Cytauxzoonosis had never been reported in North Carolina. However, NC State’s Veterinary Teaching Hospital (VTH) has seen a recent “uptick” in cases of Cytauxzoonosis in recent years, going from about one per year in the late 90’s to a current rate of one-to-two cases per week during the peak of tick season, between the months of May and July.

“There are a couple of reasons we believe we are seeing this increase in Cytauxzoonosis,” Birkenheuer says. “One is the change in the distribution of the tick species that can transmit the infection to domestic cats. One of the tick species in particular, Amblyomma americanum, has a geographic distribution that is rapidly expanding north and east. The other reason we’re seeing the increase is that some cats survive the infection and can act as a reservoir leading to the infection of more cats.”

The symptoms of Cytauxzoonosis are lack of energy and appetite, usually accompanied by a profound fever. Some cats develop a yellow discoloration of the skin and the whites of the eyes. Veterinarians can diagnose the disease by examining a blood smear or cells from infected tissues like lymph nodes, liver or spleen. In some cases, a DNA test can be used to confirm infection.

The best protection against Cytauxzoonosis is to keep cats indoors and use a treatment that is approved to kill ticks on cats (some canine products can be toxic to cats); however, the use of anti-tick products alone may not guarantee the prevention of infection. Consult your veterinarian immediately if you detect any signs of the disease in your cat.