What is Coccidioidomycosis?

Valley Fever, caused by Coccidioides, is a fungal infection affecting primarily dogs and cats, but other animals can also be infected. Within the U.S, most infections occur in the arid climates of the Southwest, although infections can occur sporadically anywhere. Infection ranges from life-threatening to mild and can affect any organ, commonly including the lung, eyes, skin, lymph nodes, bones, and nervous system. Clinical signs can be vague (decreased appetite, decreased activity level, weight loss, and fever) or more specific (limping, skin lesions, vision loss, trouble breathing, or coughing). Diagnosis can be made by finding the fungi in body fluid or tissue samples or by testing blood or urine for immune response (antibody) or small pieces of the fungi (antigen).

Valley Fever is not contagious to other animals or humans but occurs when a dog or cat inhales spores from the environment. Outdoor activity and disrupting dust or soil are risk factors. Surprisingly, even cats that never leave the house can be infected, suggesting that it can be found within the home. Other animals and humans sharing the same environment might also be exposed, and it is common for multiple pets from the same household to become infected over time. If other animals are showing signs of illness, or if you have concerns, it is important to talk with your veterinarian. Early diagnosis can help with a successful treatment. If you have concerns for yourself, or other people in the household, you should talk with your physician.

Coccidioidomycosis Testing

Early detection and accurate diagnosis are critical for improved outcomes. The combination of 2 antibody tests yields the most accurate results – MVista®️ Coccidioides Canine lgG Antibody EIA and Coccidioides Antibody by lmmunodiffusion. Your veterinarian may recommend the MVista®️ Coccidioides Antigen Quantitative EIA treatment monitoring. With a wide variety of possible clinical scenarios, other non-invasive testing might be recommended by your veterinarian for an accurate diagnosis.

How is Coccidioidomycosis Treated?

Treatment includes antifungal medication. This might be given orally at home or intravenously in the hospital, depending on the severity of illness. Other treatments might also be recommended based on the severity of illness and the location of infection within the body.

Coccidioidomycosis Treatment Timeline and Veterinary Monitoring

Treatment duration is for at least 6 months and generally longer. It is important to give the antifungal medications as prescribed as this provides the best chance for a full recovery. Many animals worsen over the first few weeks before starting to get better. Improvements are slow initially, but most animals are noticeably improved at 1 month and even better at 2 months. All medications have potential side-effects, and this is true for antifungal medications. Close monitoring for medication side-effects and for response during treatment is vital. This requires veterinary visits for repeat physical examinations, blood work, and potentially other testing (antibody testing).

Valley Fever is difficult to completely clear and return of the infection (relapse) after stopping antifungal medication can occur. After treatment, it is important to continue to watch for signs of illness and talk with your veterinarian if you have any concerns. Repeat veterinary visits including physical examination, and potentially other testing (antibody testing), is also important to help detect a relapse early. Like the initial infection, relapses are treated with antifungal medication.