Sunrise Pet Clinic: Educational Information

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Valley Fever

A Common Cause of Canine Cough

Valley Fever, properly called Coccidioidomycosis, is a disease caused by the fungus Coccidioides immitis, which lives in the soil. The highest incidence of this disease occurs in the desert areas of the Southwest: Arizona, New Mexico, and parts of California and Texas.

The disease occurs in most species of domestic animals, many exotic animals, and in man. Dogs catch the disease when some of the reproductive elements (spores) of the fungus enter the body. The most frequent means of entry is through the respiratory system, as the spores are the size of tiny dust particles and are readily inhaled. The spores may also infect the body through an open wound. Once inside the body, the fungus begins to grow. In the majority of cases, the body's own defense system (immune system) will squelch the disease before it gains a serious foothold. A very large percentage, possibly greater than 90% of dogs in the Southwest, has or has had Valley Fever. If, however, the immune system fails to control the attack, clinical disease follows.

Valley Fever can occur in two forms, depending upon the location of the infection:

Primary Form: The infection has only existed 1-4 weeks from the time of exposure and is still primarily located in the lungs and thoracic lymph nodes.

Disseminated Form: The disease process had advanced, allowing the infection to spread from the original lung site to other areas of the body: to bones, joints, skin, brain, liver, kidney, and almost any other tissue.

Possible Signs of Valley Fever:

Elevated temperature of 104-105 degrees
Listlessness
Anorexia or loss of appetite
A pronounced dry, harsh cough
Swelling of joints
Skin abscesses
Limping
Incoordination
Seizures

Diagnosis and Treatment

Diagnosis of Valley Fever involves specific blood tests and X-rays by your veterinarian to determine if your pet has the disease and how advanced it may be. Treatment of Valley Fever in dogs is not a simple matter. It involves long-term therapy with close monitoring. The treatment of choice for Valley Fever is an oral drug, Fluconazole. There is no effective prevention since the fungal spores are literally everywhere in our area. The best chance for successful treatment is early detection. The prognosis is generally poor without treatment. Even with treatment the outcome is uncertain but usually effective.

Consult your veterinarian for further information on the diagnosis and treatment of Valley Fever. Your veterinarian is the most qualified person to advise you on your pet's health and welfare.