By Julie Damron December 03, 2011 12:01 AM

Valley fever or Coccidioidomycosis is a fungal infection that can develop when spores are inhaled. it affects people, dogs, cats, and other mammals. in the United States it is common in certain parts of Arizona, California, New Mexico, Nevada, Texas, and Utah. in California the fungus is present in the San Joaquin Valley and Central Valley. in the United States, 50,000 to 100,000 people contract this illness annually. Sixty percent of the time when spores are inhaled by animals or people, there is no illness created. when animals or people do become infected with Valley fever, they are not a source of disease for others.

This fungus resides in the soil and can exist several inches below the surface. it is dormant in the dry months, and becomes active with rain. As Coccidioidomycosis proliferates, spores are formed that break off. these spores are released into the air with any disruption of the dirt. People that work in construction, farming, and other jobs involving soil are more at risk for exposure to Valley fever.

When illness is present, there are two different forms. The primary form mainly involves the lungs, and symptoms can include coughing, fever, low energy and loss of appetite. it takes about three weeks for the initial symptoms to occur. when the spores are inhaled, they can form larger structures in the lungs called spherules. these structures grow, produce more spores, and can burst, releasing more spores into the lungs. if this continued uncontrolled, the spores can spread to other parts of the body. in this advanced or disseminated form, Valley fever can involve joints, skin and other organs. this disseminated form is much more difficult to treat, and some cases can result in death.

It can be challenging to identify this illness in animals. Coccidioidomycosis is much more common in dogs than cats because dogs often dig or sniff at the ground. Large breed, young, male dogs are the common group afflicted with this malady. in the primary form, a canine might present with similar symptoms to people including weight loss, low energy, low appetite, coughing or fevers. The disseminated form can involve bones, skin, brain and other organs. Symptoms vary depending on what tissues are affected. Signs can include but are not limited to severe lethargy, limping, swelling of legs, moderate cough or difficulty breathing, fluid buildup in the abdomen or chest, eye inflammation, back or neck pain, heart failure, seizures and more.

Cats are very resistant to Valley fever, and their illness is typically much less severe than in dogs. The main form of infection for felines presents as non-healing, oozing skin wounds that can become abscesses. Cats can also show low energy, low appetite and weight loss. Felines can have lesions in the lungs but they often don’t show respiratory signs.

Valley fever can be tricky to diagnose in animals because symptoms are so varied. most commonly it is diagnosed using X-rays, blood work or biopsies. unfortunately, fungal tests can be negative in the early stages of illness. Treatment is with antifungal medications for six to 12 months. it is important to monitor liver values because these medications can be damaging to the liver. Supportive therapies are also used based on symptoms, and commonly include anti-inflammatories, pain medications, cough suppressants, and appetite stimulants. some alternative therapies are also being used to boost the immune system. if your buddy has any of these symptoms, and you suspect potential exposure to Valley fever, please seek veterinary care for your cherished companion at the first sign of illness. this yields the best chance for full recovery from this potentially devastating illness.

This column is dedicated to the memory of a Zen Davis, a Weimaraner who lost his life this year to Valley fever. he was rescued from Northern California Weimaraner Rescue, and he passed away on July 31. his mom, Chrissy Davis, has created a nonprofit to help the families of dogs who are infected with Valley fever. The website is zenspeaks.org. this venue is designed to educate, provide emotional support, and when able to give financial support for treatment in canines fighting this illness. Davis also plans to have a grief forum on this site in the near future. Donations can be made to this organization via a PayPal link on the website.

Julie Damron is a veterinarian at Sierra Veterinary Clinic in Stockton. Contact her at features@recordnet.com.

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