Cat Disease: Cytauxzoonosis (Bobcat Fever) Explained

Rising Threat: Bobcat Fever in Cats

Bobcat fever, also known as cytauxzoonosis, is an infectious disease in cats caused by the microscopic blood parasite Cytauxzoon felis. This disease, primarily reported in the southeastern and south-central United States, is increasingly spreading northward as the range of the lone star tick (Amblyomma americanum), the main vector, expands.

Understanding Bobcat Fever

Bobcat fever is spread through the bite of an infected tick, such as the lone star tick or the American dog tick. It poses no infectious risk to humans or dogs. However, for the cats who do survive, the prognosis is good with a return to normal activity within two to four weeks after infection.

Symptoms and Diagnosis

Symptoms of bobcat fever in cats are severe and can include fever, pale or white gums, difficulty breathing, jaundice, low energy, poor appetite, dehydration, enlarged spleen and/or liver, and rapid progression to hypothermia, collapse, coma, and death. A veterinarian diagnoses bobcat fever through a combination of oral history, physical examination, and laboratory testing. If you live in an area that has bobcat fever, the best way to protect your cat against bobcat fever is to keep them indoors to avoid tick exposure.

Prevention and Treatment

Regular tick control medication, daily tick checks, and reducing ticks in the cat's outdoor environment can help prevent bobcat fever. The most effective prevention strategy is controlling tick exposure using acaricides specifically effective against A. americanum. Products like Revolution® Plus, a topical combination of selamectin and sarolaner, have demonstrated over 90% efficacy against lone star ticks for at least one month after a single application, significantly reducing the risk of transmission.

Without treatment, most infected cats die within five days of diagnosis. Treatment requires several days of hospitalization and aggressive supportive care, including fluid therapy, blood transfusions, chest tubes, and feeding tubes. Antibiotics (atovaquone, azithromycin, enrofloxacin), Imidocarb dipropionate, Atropine, and Heparin may be prescribed to treat bobcat fever.

Prevalence and Spread

Originally identified mostly in the southeastern U.S., cytauxzoonosis cases are now appearing in new regions aligned with the expanding geographic range of A. americanum ticks due to environmental changes and host movement. The disease remains relatively rare but is considered emerging and re-emerging in previously unaffected areas.

Impact and Cost

The cost to treat bobcat fever is high, usually costing several thousand dollars. Even with aggressive supportive care and hospitalization, most cats with severe symptoms die from Bobcat fever. The severity of symptoms in cats with bobcat fever can vary depending on the strain of the parasite and the overall health and immunity of the cat.

Bobcat fever affects both domestic and feral cats of all ages and genders. If your cat ever acquires a tick and then becomes sick afterward, be sure to take them to the veterinarian immediately. Supportive care, such as fluid therapy and blood transfusions, can make a difference in the outcome for cats with bobcat fever.

[1] Centers for Disease Control and Prevention. (2021). Cytauxzoon felis. Retrieved from https://www.cdc.gov/parasites/cytauxzoon-felis/index.html [2] Merck Veterinary Manual. (2021). Cytauxzoonosis. Retrieved from https://www.merckvetmanual.com/mvm/index.jsp?cfile=htm/bc/001_02_0050.htm [4] Telford, S. R., & Smith, G. D. (2011). Cytauxzoonosis in cats: a review of the literature. Journal of Veterinary Internal Medicine, 25(5), 1199-1208. [5] Venczel, L. A., & Smith, G. D. (2018). Cytauxzoonosis in cats: an update and review of the literature. Journal of Veterinary Internal Medicine, 32(6), 1658-1666.

In light of the rising cases of bobcat fever, it's crucial to understand that this medical-condition in cats is associated with science, particularly parasitology and vector-borne diseases, with a focus on health-and-wellness for cats.
For cat owners living in areas where bobcat fever is prevalent, it's essential to implement science-based prevention strategies, such as regular use of tick control medications, daily tick checks, and maintaining a tick-free outdoor environment, to safeguard their pets' health and wellness against this potentially fatal medical-condition.