New residents moving from other parts of the United States to the Southwestern United States may have never heard of Valley Fever. But quite a large number of dogs and other animals will contract Valley Fever every year. It’s important to learn how your pet contracts Valley Fever and how to recognize the symptoms.
What Is Valley Fever?
Valley Fever is caused by a fungus found primarily in low Southwestern U.S. desert regions. Animals inhale the spores of the fungus from the air or by digging, in construction areas where the soil has been disturbed or when high winds carry spores.
When the animal inhales the spores (either a few or a lot of them), the spores continue to grow inside the lungs until they rupture, discharging hundreds of new spores. The infection continues to grow until the animal’s immune systems respond and kill the infection. But animals with weakened immune systems may not be able to stave off the ever-multiplying spores.
Where Is Valley Fever Found?
In the United States, Valley Fever is found in Southwestern U.S. low desert regions. It is common in Arizona, interior deserts of California, New Mexico and southwestern Texas.
What Animals Get Infected?
Dogs are the most common animal to develop Valley Fever. Other animals who may get Valley Fever are apes, cats, cattle, horses, llama, monkeys, native wildlife (like cougars or skunks) and zoo animals.
How Is It Spread?
Valley Fever is not contagious. It can only be contracted by an animal inhaling the spores. Even pets living in the same household can’t spread the disease. But if both of your dogs exercise in an outdoor area where the spores are found, both dogs may inhale the airborne spores.
What Are the Symptoms?
Symptoms in dogs include:
- Decreased appetite
- Low energy level/lassitude
- Weight loss
Their cough can be a hacking cough or a honking (like a goose) cough caused by swollen lymph nodes pressing up against their windpipe.
If the infection spreads, known as a disseminated disease, Valley Fever often spreads to the bones causing limping or paralysis. They might also have seizures, swollen lymph nodes that you might feel, swollen testicles or heart failure might strike a younger dog.
Cats with Valley Fever usually have a non-healing skin lesion. It might look like an abscess and drain pus. Valley Fever is much less common in cats – for every 50 dogs diagnosed, only 1 cat will present with Valley Fever.
How Is Valley Fever Diagnosed?
If your pet has symptoms suggestive of Valley Fever and has been in low desert areas recently, be sure to mention their travel history. Your veterinarian is likely to utilize the following tests:
- Valley Fever blood test, also known as the cocci test
- Bone or joint X-rays, if your pet is limping or lame
- Chest X-ray if your pet has a severe cough
- Complete blood count
The Valley Fever blood test might have to be repeated in 3-4 weeks to confirm the diagnosis. If tested early in the course of the disease, the test might come back negative.
When cats present with an abscess or draining lesion, the Valley Fever blood test will also be utilized along with a biopsy of the lesion. Chest x-rays detect lung lesions, even if the cat is not coughing.
What Are the Treatment and Prognosis?
The outlook is good for dogs whose infection is limited to their lungs. Dogs who have disseminated disease may need a yearlong course of medication. Most return to normal health. Extensive disease throughout the body is associated with a poorer prognosis.
Follow-up is recommended after treatment has ended, particularly in animals with disseminated disease. Relapses may occur.