Valley Fever in Dogs: Recognition and Long-Term Management

Coccidioidomycosis (valley fever) is a potentially serious fungal infection in dogs from endemic regions requiring long-term antifungal treatment.

Key Facts

Valley fever is caused by Coccidioides immitis, a fungus found in soil in the southwestern US, Mexico, and parts of South America
Dogs are infected by inhaling fungal spores from disturbed soil
Signs range from mild respiratory illness to severe disseminated disease affecting bones, brain, and eyes
Bone and joint dissemination causes severe lameness and pain
Diagnosis uses serology (IgM and IgG titers) alongside clinical signs and imaging
Fluconazole is the primary treatment - lifelong therapy may be required for severe cases
Some dogs achieve cure after 12-18 months of treatment; others require permanent medication

Welfare Considerations

Valley fever causes genuine suffering when disseminated - severe bone pain from osteomyelitis, respiratory compromise from lung disease, and neurological signs from CNS involvement all represent significant welfare impacts. Early diagnosis before dissemination provides the best welfare outcomes. Dogs in endemic regions with unexplained lameness, fever, or weight loss warrant serological testing. Long-term antifungal treatment is well-tolerated and significantly improves quality of life in affected dogs.

What You Can Do

Consider valley fever serology testing for any dog with unexplained illness in endemic regions
Begin antifungal treatment promptly on diagnosis - early treatment prevents dissemination
Monitor treatment response with periodic titers every 3-6 months during therapy
Be prepared for long-term or lifelong treatment in severe or disseminated cases
Minimize soil disturbance exposure in endemic areas, especially during dry, windy conditions