Stan Wood, DVM, Diplomate ABVP

Specialist in Canine & Feline Practice

Cytauxzoonosis in Cats

Cytauxzoonosis is a serious, invariably fatal disease of the cat. It occurs when the cat is bitten by a tick; usually Dermacentor variabilis, or the American dog tick, is involved. A single tick bite can successfully transmit the organism to the cat. The domestic cat is thought to be an “accidental” host for this parasite. The natural reservoir for the organism is the bobcat; in this species, the organism may survive for long periods of time.

Clinical Signs

The signs are generally vague. Most owners first report affected cats to be depressed and have a decreased appetite. A very high fever (>106 F) is common. After a day or two, the cat will become anemic and jaundiced (develop a yellow color to the skin and in the mouth) with increasing lethargy.

Diagnosis

When this disease is suspected, a stained blood smear is examined in search of the organism. It can often be seen under the microscope with diligent searching. In other cases, the diagnosis may not be made until the cat is autopsied.

Risk Factors

Known risk factors for this disease include the following:

1. Warm weather

2. Access to a wooded outdoor environment

3. Exposure to ticks

Treatment

At this time, there is no known treatment for this disease. Therefore, this disease is generally considered to have a 100% fatality rate. Most cats are dead within 5 days from the first observed signs of illness.

Prevention

The best way to prevent this disease is to eliminate any potential exposure to ticks. The most reliable means for achieving this is keeping the cat indoors. If you have dogs, which have access to the outdoors, ticks may still be brought inside. Check your cat regularly and, should you see any ticks on the cat, remove them with tweezers. Strict tick control is essential. We recommend Frontline Top Spot as the most effective, safe, and practical means of tick control for cats.

Transmission to Humans

This parasite has not been diagnosed in humans. Therefore, to the best of our knowledge, there is no health risk to humans.