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What are the symptoms?

The cat becomes depressed, withdrawn, relatively motionless, runs a very high fever (103 -107 F), & refuses to eat. The clinical description of “hemolytic crisis”, “tissue microphages with production of schizonts & invasive merozoites” & other academic jargon, basically means that while the cat burns with fever, becoming anemic & dehydrated, the disease rages through the body attacking blood vessels in all organs; heart, lungs, liver, kidney, spleen. Under such systematic attack the liver & kidneys quickly overload with damaged blood cells & the body becomes jaundiced. In the end phase, the cat begins to vocalize frequently & at greater & greater length, a heart-rending agonal cry, hemorrhages, & dies.

Is the disease in my area?

  One of the Oklahoma State University web pages calls cytauxzoon felis a “uniformly fatal” parasite affecting domestic felines in North America, & notes that similar genus infect a variety of African animals, but this protozoan occurs only in the US, predominately in the south eastern & south central states.
  Cases have been reported in Arkansas, Florida, Georgia, Illinois (southern),Kansas, Kentucky, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, South Carolina, Tennessee, Texas & Virginia. Actually all of the Southeastern & Midwestern US states are at risk. Interestingly enough, lab research pathologies show that the organisms are nearly identical in every region even though the infected cats are from different regions. Ask your vet about the predominance of cases in your area.

cytauxzoonosis resource

What is cytauxzoonosis?(Pronounced “Sy-toe-zo-ono-sis”.)

Cytauxzoon felis is a protozoan organism that causes a disease in cats called feline cytauxzoonosis ,or “bobcat fever"

Does it affect only cats?

Yes. Wild felis domesticus can be infected as well; it doesn’t just target pets. There has been one documented of infection in a captive-reared female white tiger (Garner, M.M. Lung, N.P, Homer, B.L. Veterinary Pathology, Jan 01, 1996.) The cat is what is known as a “dead-end host”, when the protozoan kills the cat, it dies, too.

How quickly does it progress?

Symptoms appear within 7-10 days of infection, i.e. the tick bite. It is rapidly fatal; death usually occurs within 3 - 6 days from the first symptoms of illness.

How is it diagnosed?

The only way to definitively diagnose cytauxzoonosis is to take your cat to the vet. The vet will take blood samples, which can then be screened for the presence of the organism. The cytauxzoon pattern is easily distinguished from other organisms. There is an early interim phase where the clinical symptoms are present but the pattern does not show up

How is it transmitted?

The disease is passed from bobcats to domestic cats by ticks, specifically dermacentor variabilis, the American Dog tick. The bobcat is an asymptomatic carrier; it is not affected by the disease. Ticks bite bobcats, pick up the cytaux protozoa while feeding, fall off, then feed on other animals. Hard-bodied ticks in general are classified as 1-, 2-, or 3-host ticks, depending on how many hosts the tick feeds on during its development. The American Dog tick is classified as a 3-host tick, which increases the potential for disease transmission due to the higher number of animals exposed. They eventually lay eggs and pass on the protozoan to their offspring, which may number in the thousands. After they hatch, the larvae crawl up a blade of grass or other object & wait for a suitable warm-blooded host to stroll by. It is looking for any warm-blooded host, but if what strolls by a cytauxzoon-carrying tick is felis domesticus, the common housecat, & the tick bites the cat & feeds for long enough to transmit the disease, the cat is in serious trouble.

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2006 Helios Project