Cat Valley Fever Infection: Emerging Geographic Threat

Coccidioidomycosis from endemic soil fungi poses a growing welfare threat to cats in expanding southwestern US regions as climate change widens the endemic zone.

Key Facts

Valley fever is caused by Coccidioides fungi living in dry desert soil throughout the southwestern US and Mexico
Climate change is expanding the endemic zone northward and eastward into previously unaffected regions
Cats are generally less susceptible than dogs but can develop severe disseminated disease
Respiratory signs, weight loss, and bone or skin lesions characterize disseminated coccidioidomycosis
Antifungal treatment with fluconazole may need to continue for 12-18 months or lifelong in severe cases

Welfare Considerations

Cats with disseminated valley fever suffer from multiple system involvement including chronic respiratory disease, painful osteomyelitis from bone lesions, and the systemic effects of profound fungal infection. The diagnostic challenge of distinguishing valley fever from neoplasia and other causes of weight loss means many cats are treated for the wrong condition. Welfare is also affected by the prolonged nature of treatment, requiring long-term antifungal medication. Geographic expansion of endemic zones means veterinarians in non-traditional areas may lack familiarity with valley fever presentations, further delaying diagnosis and treatment.

What You Can Do

Be aware of valley fever if you live in or travel to the southwestern US or northwestern Mexico with your cat
Alert your vet to potential endemic area exposure if your cat develops respiratory or bone disease
Support continued geographic monitoring of Coccidioides distribution as a public and animal health resource
Minimize soil disturbance and dust exposure for cats in endemic regions during dry, windy conditions