Valley Fever, or Coccidiodomycosis is a very common diagnosis in dogs (and occasionally cats, ferrets, wallaby…..) here in Tucson. We thought we should put together a list of common questions and issues that a family caring for a recently diagnosed Valley Fever patient might need to know. Thank you to Courtney Williams CVT, for putting this together.
What is Valley Fever?
Valley Fever is caused by a fungal spore that lives in desert soil. It is most commonly found in the Southwest regions of the United States, and in northern Mexico. In southern Arizona, New Mexico, Southwest Texas and some desert regions of California. The most common symptoms associated with Valley Fever are coughing, lethargy, decreased appetite, muscle soreness, or fever. We also see intermittent limping, seizure activity or other neurological abnormalities. Occasionally, we will diagnose a patient with skin or eye lesions. An animal could exhibit any variety of these symptoms.
How did my pet get Valley Fever?
Pets become infected with Valley Fever after they have inhaled a fungal spore from the ground or in the air. During the last stage of the spore’s life cycle, it becomes very dry and delicate. Once the soil is disturbed (by digging, walking, construction, or high winds) it becomes airborne and consequently inhaled. Once the spores enter the lungs, they continue to grow and burst to release hundreds of spores. In most cases, the body’s immune system is able to kill them, but in about 30% of cases they are not killed quickly enough and continue to spread throughout the body. All people and animals that have lived in the Southwestern areas for any length of time have been exposed to these fungal spores. Luckily, about 70% are able to fight off the fungus and remain asymptomatic.
How is Valley Fever treated?
The most important thing to know about treatment is that it is NOT black and white. Every patient is treated as an individual, depending on their response. The preferred treatment is with an oral anti fungal drug called Fluconazole. The drug doesn’t actually kill the fungus; rather it prevents it from spreading while the animal’s own immune system fights off the infection. Often times an immune-supportive supplement will also be prescribed along with the Fluconazole. It is also very important to ensure proper nutrition with a well-balanced, high quality diet. Before a couple of years ago, Fluconazole was an inexpensive, widely available drug. However, currently there is only one manufacturer of the human generic Fluconazole, so the price has gone up exponentially (by about 1,000 percent!!). Luckily, we’ve found that many compounding pharmacies can supply Fluconazole for a MUCH more reasonable price.
What is the risk of exposure for my family and other pets?
Fortunately, Valley Fever can almost never be transmitted directly from one animal to another. It is considered an infections disease but not contagious. The only exception is when the disease manifests through open lesions in the skin. This stage of disease is very uncommon.
What is a Valley Fever test/titer?
A titer is used to measure a patient’s antibody level to Coccidioidomycosis – a “Cocci titer”. A sample of your pet’s blood is tested, and if it’s positive it then is diluted with saline by half increments until it tests negative. It is expressed in a ratio as follows; 1:2, 1:4, 1:8, 1:16, 1:32, 1:64… and so on. The higher the titer, the more Valley Fever antibodies the patient’s immune system is producing. This doesn’t always mean that an animal with a higher titer is sicker than one with a lower titer. The severity of symptoms is affected by how well the pet’s own immune system is able to fight off the infection. In many cases we can see a very sick patient with a negative , or low titer. Which leads to a very important question, why would we still suspect Valley Fever in an animal with a negative titer? Luckily there are a few other indicators in the blood that lead us toward a diagnosis. Sometimes we identify specific symptoms or see “classic lesions ” on a radiograph that indicate infection. On occasion, we do a trial-run by treating the pet with Fluconazole for a month and see if their symptoms start to improve.
How often does my pet need blood monitoring?
At Sabino Veterinary Care typically evaluate our patients about 30 days after we start treatment. We look at some kidney and liver blood tests to evaluate how the patient is metabolizing the medication. If they end up being on treatment long term, we decrease the frequency to every 6 months to 1 year. Following is a routine schedule for blood monitoring:
- Liver/kidney chemistries are checked after 1 month on Fluconazole
- Chemistries, Complete Blood Count, and Valley Fever titer are checked after 6 months.
- Depending on their response to treatment, blood work is rechecked every 6-12 months.
Will my pet ever be cured from Valley Fever?
The good news is that the majority of pets will recover from Valley Fever, especially if the disease is caught and intervention is started early. The prognosis and length of treatment varies greatly depending on where the disease is affecting the body. The most common form is that which affects the lungs and causes coughing, lethargy, or anorexia. In more complex cases, the disease can affect the brain, spinal cord, bones, or vital organs like the heart, liver or kidneys. It is extremely important to continue on with treatment unless otherwise directed by a Veterinarian. Your pet will start to feel better once on medication, but if treatment is stopped too soon they can easily relapse and become sick again.