* What is Valley Fever?

Valley Fever (Coccidioidomycosis) a disease caused by a fungus, Coccidioides immitis, which exists as a mold found in the soil. Working the soil (ie: construction, landscaping) will increase the chances of coming in contact with the fungus. Also, dogs that dig are more prone because they are breathing in all the dirt as they dig.

* Is Valley Fever more prevalent in some areas?

The highest incidence of Valley Fever occurs in the desert areas of the Southwest: Arizona, New Mexico, southwestern Texas and the central deserts of California.  The environmental conditions necessary for the survival of the fungus include warm, arid climate, low elevations with small amounts of rainfall and relatively alkaline soil.  Dogs who travel through the areas - or winter with their people in those areas - can also be infected.

* What are the symptoms of Valley Fever?

Because there are two forms of Valley Fever, clinical signs of the disease are variable. The primary form is that which gets into the lungs. With this form, the most common sign is a persistent cough. Many times this is the only sign, but symptoms may also include not eating well, weight loss, fever, or lethargic behavior. Sometimes there are no clinical signs of the disease until it shows up on blood work.

The other form of the disease is disseminated Valley Fever (meaning the fungus has spread to other parts of the body). This form most commonly goes to a bone, but can invade the brain, skin, eyes, or almost any other tissue. With this form the animal is usually limping on a limb. Other signs include weight loss, swelling of joints, back or neck pain, swollen lymph nodes, unexpected heart failure in a young dog, lack of coordination, seizures, or sudden blindness.

* What tests are run to confirm Valley Fever?

To confirm a diagnosis of Valley Fever, blood tests are needed. X-rays may show a suggestive pattern in the lungs or bones, but blood work is best. It will show not only if the dog has it, but also gives a titer, which shows how bad the infection is. The titer is a good way to measure the response to treatment.

Because of the high incidence of Valley Fever in certain areas, veterinarians like to test any dog that is ADR (Non-medical term for "Ain't doing right." This is generally a non-specific term for an animal that has no specific complaint except "not himself" or more lethargic, etc.) Many vets like to test animals before a major surgery, or if they have another medical condition such as diabetes or kidney problems. Valley Fever can complicate an ongoing disease. In addition, some vets will test any animal experiencing seizures before they will say the cause is epilepsy.

A word of caution, though: Sometimes tests are negative early in the infection so if symptoms continue, a blood test might need to be repeated.

* How is Valley Fever treated?

Treatment of Valley Fever can be very challenging. The treatment will vary with the severity of the infection, but generally, treatment consists of oral antifungals. The most common drug is Fluconazole, but there are other antifungals available such as Ketoconazole, Itraconazole and Amphotericin B.  The primary form of Valley Fever (by far the most common) will usually require treatment for 6-12 months and the disseminated form may require lifelong treatment. The cost of the medication may be prohibitive for some owners to continue treatment, as it is dosed by weight and can cost $100 and up per month.

Treatment depends on the individual veterinarian and dog. Treatment decisions are based on the severity of the infection, side effects, cost, and convenience to the owner.  Note:  side effects are possible with all the medications, including increased liver enzymes.

* Is there a chance of long-lasting problems even if my Boxer is treated?

The primary form is generally treatable and has no lasting effects other than mild tissue damage to the lungs. The disseminated form may never be cleared 100%, and will need multiple bloods tests in order to monitor the disease.

* If my dog gets Valley Fever, is she protected from getting it again?

Getting Valley Fever and clearing it does not make a pet immune from getting it again.

* Is Valley Fever contagious?

Valley Fever is not contagious from animal to animal or from human to animal. However, if one dog gets it, it is likely that other animals in that household will come into contact with the fungus, especially if they are in the same yard or all are diggers.  Another point of information: People can contract Valley Fever and need to see a physician for treatment.

* Is there anything that can be done to reduce the chances of a dog getting Valley Fever?

There is no known preventative for Valley Fever other than decreasing exposure to the desert soil and dust.  In other words, try to avoid activities or behaviors that generate dust such as reducing digging, preventing dogs from sniffing in rodent holes, and keeping dogs indoors during particularly dusty times. This is not always easy, but worthwhile if you can manage it.  A vaccine is being developed but there is no estimate on when it might be available.

Source: Valley Fever Center for Excellence (University of Arizona - Tucson, AZ)

Copyright © 2012 Maryann Watkins

Valley Fever:
Frequently Asked Questions

by Maryann Watkins
Dog Safety