Bobcat fever: Veterinarians emphasize year-round tick control for cats as cases climb in Oklahoma

A rise in bobcat fever cases across Oklahoma—including a recent fatal case in the Oklahoma City area—has state veterinarians urging cat owners to keep pets on tick prevention and to watch for the early, easily missed signs of a disease that can kill within days.¹

Bobcat fever, known clinically as cytauxzoonosis, is caused by the protozoan parasite Cytauxzoon felis and is spread to domestic cats primarily through the bite of the lone star tick (Amblyomma americanum).^1,2 The disease is a veterinary emergency: even with prompt, aggressive care, only about 60% of treated cats survive, and untreated cats that develop clinical signs typically live just a few days.^2,3

For practitioners in enzootic regions, the Oklahoma reports are a timely reminder to keep cytauxzoonosis high on the differential list this time of year—and to reinforce prevention messaging with clients before a cat presents in crisis.

A narrow window from tick bite to collapse

Cats become infected when a feeding tick inoculates sporozoites into the bite wound. The organism first multiplies inside macrophages, producing large schizonts that obstruct blood flow—particularly in the lungs—before merozoites are released to invade circulating red blood cells.² That schizont phase, not the erythrocytic stage, drives the severe disease, disseminated intravascular coagulation, and shock that make the condition so often fatal.²

Clinical signs generally appear about 10 days after the tick bite and progress fast.² Early presentations can be nonspecific—lethargy, decreased appetite, hiding or unusual withdrawal, and fever—which is precisely why owners may not recognize the urgency.^1,3 From there, cats commonly develop high fever, dyspnea or tachypnea, dehydration, anemia, icterus, and enlarged lymph nodes, often deteriorating to hypothermia, recumbency, coma, and death within a week of onset.^2,3 Cats presenting with hypothermia or respiratory distress carry a particularly poor prognosis.²

Diagnosis and a treatment protocol that must start early

Definitive diagnosis rests on identifying piroplasms within erythrocytes on a stained blood smear, or large schizonts in splenic, lymph node, or bone marrow aspirates; whole-blood PCR is also available and is most reliable when samples are drawn early and before treatment begins.² Supporting clinicopathologic findings include nonregenerative anemia, leukopenia, thrombocytopenia, elevated liver enzymes, hyperbilirubinemia, and hypoalbuminemia.²

The currently recommended protocol pairs atovaquone (15 mg/kg PO q8h for 10 days) and azithromycin (10 mg/kg PO q24h for 10 days) with aggressive supportive care—intravenous fluids, nutritional support, and blood transfusions as needed.² Survival rates reach roughly 60% when combination therapy is started promptly, which underscores the value of early recognition and referral.² The older imidocarb dipropionate protocol has largely fallen out of favor because of reduced efficacy and inconsistent results.² There is no protocol to clear the organism from chronically infected cats, and survivors remain lifelong subclinical carriers.²

Prevention is the message for clients

No vaccine exists, so prevention hinges on tick avoidance.² The Companion Animal Parasite Council advises keeping cats indoors when possible, applying effective year-round acaricides, performing daily tick checks, and removing attached ticks promptly.² Practitioners can also counsel clients on habitat management—clearing debris and keeping grass and shrubbery trimmed to discourage both ticks and the wildlife that harbor them.²

Two points are worth emphasizing with owners. First, indoor cats are not automatically safe: households with dogs or other pets that go outdoors can still bring ticks inside.³ Second, while bobcats (Lynx rufus) are the traditional reservoir—with C. felis prevalence reported as high as 80% in some bobcat populations—recent research suggests feral domestic cats may play a larger role in maintaining the parasite than previously appreciated.² Cats that survive infection should be kept indoors permanently, both for their own protection and to limit the tick-mediated spread that a carrier cat can seed.^2,3

Most U.S. cases occur in the southeastern and south-central states between March and September, when tick vectors are active²—placing Oklahoma squarely in the seasonal and geographic crosshairs, and making now the moment to get prevention conversations in front of clients. Reassuringly for those conversations, C. felis is not known to infect people.²

References

1. Cox B. Bobcat fever cases rise in Oklahoma as veterinarians urge tick prevention for cats. News On 6. July 9, 2026. Accessed July 9, 2026. https://www.newson6.com/tulsa-oklahoma-news/bobcat-fever-oklahoma
2. Cytauxzoonosis. Companion Animal Parasite Council. Updated October 3, 2025. Accessed July 9, 2026. https://capcvet.org/guidelines/cytauxzoonosis/
3. Boldan M. Bobcat fever in cats: symptoms, treatment, and prevention. PetMD. March 1, 2026. Accessed July 9, 2026. https://www.petmd.com/cat/conditions/infectious-parasitic/bobcat-fever-in-cats