Fourth human case of "rabbit fever" confirmed on Long Island amid decade-high tick activity. Here's what veterinarians should know

Suffolk County, New York, health officials confirmed a 4th case of tularemia, commonly called "rabbit fever, "on Long Island this week. Tularemia is a rare but potentially serious zoonotic disease caused by the bacterium Francisella tularensis, spread most often through the bites of infected ticks and deer flies and through contact with infected animals.³ The cluster comes as human emergency-department visits for tick bites run at their highest level in nearly a decade, with the Northeast and Midwest hit hardest.⁴

Gregson Pigott, MD, MPH, commissioner of the Suffolk County Department of Health Services (SCDHS), confirmed the latest case to ABC News, as shared in an August 6 report. Earlier in the week, the department had reported 3 probable cases for the year.² Although tularemia is rare, the county has recorded cases in several recent years, including 3 in 2023, 4 in 2024, and 6 in 2025, according to Pigott.¹

What is tularemia?

Tularemia is caused by F. tularensis, a gram-negative coccobacillus that is highly infectious. It takes only a very small number of organisms to cause disease, which is part of why it is handled so cautiously in the laboratory.³ The bacterium is inactivated by heat and by disinfectants routinely used for clinic infection control, but it can survive for weeks to months in a moist environment.⁵

The disease affects more than 250 species of wild and domestic mammals, birds, reptiles, and fish.⁵ In North America, it is most often found in wild rabbits, hares, and rodents, which are highly susceptible and can die in large numbers during outbreaks.³ Among domestic animals, sheep are most commonly affected, though infection has also been reported in cats, dogs, pigs, and horses.⁶ Cats, in particular, pose a special concern in small-animal practice, as they can acquire the organism by hunting infected prey. Dogs, meanwhile, are relatively resistant and infection in them is rare.⁷

People and animals are infected through the same main routes, which include bites from infected ticks or deer flies, contact with or ingestion of infected animals, inhalation of contaminated aerosols, and drinking contaminated water.³ In the United States, most cases trace to the bites of infected ticks, including dog ticks, wood ticks, and lone star ticks.⁸ The disease does not spread from person to person.³

"It's often called rabbit fever because hunters who shoot rabbits and then skin and eviscerate them can become contaminated by that close contact with their tissues," William Schaffner, MD, a professor of preventive medicine at Vanderbilt University Medical Center in Nashville, said in an ABC News report.¹

Clinical signs in animals

Clinical signs depend on the host species, bacterial subspecies, and route of infection.⁵ In cats and dogs, presentation varies and may include fever, lethargy, lymphadenomegaly, loss of appetite, vomiting, diarrhea, coughing, nasal discharge, and oral ulcers.⁵ Across affected species, signs also include pneumonia and hepatosplenomegaly.⁵ In cats, the disease can range from inapparent infection to severe disease, and presentation is often peracute, meaning an affected cat may be found dead.⁶

In wild animals, tularemia is usually diagnosed on postmortem examination. In domestic animals, the diagnosis rests on clinical signs and ruling out other causes.⁸

Diagnosis and treatment

Diagnosis in animals is confirmed by bacterial culture, serologic testing, or PCR assay.⁵ F. tularensis can be cultured on cysteine-supplemented blood, and isolation from necropsy specimens requires a laboratory equipped for biosafety level 3 procedures.⁵ The laboratory should be alerted whenever tularemia is on the differential. When handling or sampling a suspected case, staff should wear personal protective equipment, and at minimum, gloves, gown, mask, and eye protection to prevent zoonotic transmission.⁶ Because tularemia can spread to people, animal infections are reportable to public health authorities in some jurisdictions.⁶ Antimicrobial treatment can be effective when started early.⁵ There is no tularemia vaccine generally available in the US.¹

Tularemia cases come amid high tick season

The cases arrive during an unusually heavy tick season. The CDC reported this spring that weekly emergency-department visits for tick bites reached their highest level for the time of year since 2017, with the Northeast and Midwest hit hardest.⁴ According to the agency, activity began ramping up earlier than usual, pointing toward a longer season.⁴ Cases of tularemia typically peak from May through September.³

Veterinary teams can share the CDC's prevention advice with clients, such as using EPA-registered insect repellent, wearing long sleeves and pants, removing attached ticks promptly, avoiding mowing over dead animals, and wearing gloves when handling sick or wild animals.¹

Keeping cats indoors and maintaining year-round tick control also reduce the chance a companion animal brings the organism home.

References

1. Kekatos M. 4th case of 'rabbit fever' reported in New York. Here's what to know. ABC News. August 6, 2026. Accessed August 6, 2026. https://abcnews.com/Health/rabbit-fever-amid-3-probable-cases-reported-new/story?id=135321741
2. Scribner H. "Rabbit fever" suspected in New York as rare illness resurfaces. Axios. August 4, 2026. Accessed August 6, 2026. https://www.axios.com/2026/08/04/tularemia-rabbit-fever-new-york-tick-illness
3. Centers for Disease Control and Prevention. About tularemia. Accessed August 6, 2026. https://www.cdc.gov/tularemia/about/index.html
4. CDC data show weekly ER visits for tick bites higher than usual. CDC Newsroom. Accessed August 6, 2026. https://www.cdc.gov/media/releases/2026/2026-cdc-data-show-weekly-er-visits-for-tick-bites-higher-than-usual.html
5. Tularemia in animals. Merck Veterinary Manual. Accessed August 6, 2026. https://www.merckvetmanual.com/generalized-conditions/tularemia/tularemia-in-animals
6. Tularemia in cats. Merck Veterinary Manual. Accessed August 6, 2026. https://www.merckvetmanual.com/cat-owners/disorders-affecting-multiple-body-systems-of-cats/tularemia-in-cats
7. Tularemia (rabbit fever) in dogs. Merck Veterinary Manual. Accessed August 6, 2026. https://www.merckvetmanual.com/dog-owners/disorders-affecting-multiple-body-systems-of-dogs/tularemia-rabbit-fever-in-dogs
8. Tularemia in animals. American Veterinary Medical Association. Accessed August 6, 2026. https://www.avma.org/resources-tools/animal-health-and-welfare/animal-health/tularemia-animals