Valley fever is a disease caused by the fungus Coccidioides Immitis. This fungus is found in the dirt in the desert southwest region of the United States. Arizona is in the center of this region. We all breathe in the fungal spores every day. Our dogs do as well. Most of the time, a body’s immune system takes care of this invasion. Occasionally, however, the body’s immune system cannot handle the infection either because it’s weakened or because it is overwhelmed by the number of spores inhaled. Examples of situations when there increased numbers of fungal spores to be inhaled include after rain, when the yard is landscaped or when dust is kicked up from activities such as ATV rides. Fungal spores enter the lungs. The majority of the time that’s where they stay. Dogs will develop a chronic cough and become lethargic. Occasionally, however, the spores leave the lungs without causing illness. From there, the infection can go just about anywhere. Clinical signs vary and are reflective of where the organism settles. If in the bone, then a pet will experience pain and may limp. If in the central nervous system, a pet can have seizures. I have seen valley fever just about everywhere in a dog’s body. Left untreated, valley fever can progress and, in some instances, be fatal. Fortunately, most dogs respond well to treatment. Many dogs can be cured. Of those that cannot be cleared of the organism, most can usually be controlled and clinical signs minimized. Treatment requires anti-fungal medications administered by mouth twice daily for months to years. Unlike bacterial infections, which are often treated in 1-2 weeks, fungal infections take a very long time to treat. Veterinarians monitor a pet’s progress based on blood testing and clinical signs.