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What is it?
Valley Fever (also called Coccidiodomycosis) is a disease caused by a fungal
spore that is inhaled from the environment. The spore survives in the warm, arid
climates of the deserts of the southwestern United States. The disease occurs in
most domestic animal species, many exotic species and in man. It is not
contagious from animal to animal or animal to man, or man-to-man, or man to
animal. There are two forms of the disease – the primary form and the
disseminated form. The primary form develops two to four weeks after exposure,
and is primarily located in the lungs and thoracic lymph nodes. In the disseminated
form the disease has spread beyond the lungs to other areas of the body, such as
the bones, joints, brain or any other organs.
Signs
In the primary form of the disease signs may include an elevated temperature,
listlessness, anorexia and a dry, harsh cough. In the disseminated form of the
disease signs may include lameness, weight loss, chronic cough, pain, skin
abscesses, incoordination, or seizures.
Diagnosis
The diagnosis for valley fever may involve a physical examination, radiographs of
the chest or affected limb, blood serology testing and some other specialized
testing as indicated by the signs (such as a CT scan for seizures).
Treatment
The treatment for valley fever should be started immediately. If done so, we can
often prevent the primary form from becoming the disseminated form. Several
antifungal drugs can be used. The most effective oral drugs are Fluconazole
(Diflucan) and Itraconazole (Sporonox). These drugs also have the least side
effects. They are used for both forms of the disease. Ketoconazole (Nizoral) is
also used, and is less expensive than the other two drugs mentioned, but has been
associated with the side effects of loss of appetite, vomiting, lightening of the hair
coat and even liver toxicity. Occasionally, extremely ill patients might need to be
hospitalized and treated with an intravenous infusion of Amphotericin B, which may
need to be repeated over several weeks. Depending on the patient’s clinical signs,
we may use additional drugs, such as anti-vomiting drugs, painkillers, antibiotics
and seizure-control drugs. We like to monitor our patients by reevaluating them at
least every 4-8 weeks, and performing repeat blood serology tests and perhaps
follow-up radiographs.
Prevention
At this time, there is no known prevention of valley fever. However, reducing your
pet’s exposure to the desert soil and dust as much as possible may help. It
appears that areas with a lot of construction may have a higher incidence of valley
fever spores in the environment. There is no vaccine available.
