Valley Fever is a fungal, non-contagious disease in dogs caused by Coccidiodes immitis. The condition primarily affects the lungs, making dogs uncomfortable and costing owners thousands of dollars on diagnosis and treatment.

In this article, I, Ivana Crnec, DVM, will give you the basics of Valley Fever in dogs. I will explain what the disease entails, how dogs get it, what the treatment is, and how to protect your pets if traveling in dangerous areas.

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  1. What is Valley Fever in Dogs
  2. Valley Fever Symptoms in Dogs
  3. How Do Dogs Get Valley Fever
  4. Valley Fever Treatment for Dogs
  5. How to Prevent Valley Fever in Dogs
  6. FAQs
  7. Conclusion

What is Valley Fever in Dogs

Valley Fever is a fungal, infectious, and non-contagious disease affecting the dog’s lungs. It is caused by the fungus Coccidiodes immitis.

“Other common names for the disease are California disease, San Joaquin Valley fever, and desert rheumatism,” explains Jamie Whittenburg, DVM, in an article for The Wildest.

The fungus and disease are widespread in certain desert-like areas and commonly affect dogs living or traveling in endemic regions.

Interestingly, not all dogs that breathe in the fungal spores get infected. Around 70% of dogs do not show symptoms and even develop an immunity against the disease, reports the University of Arizona.

The disease is most likely to occur in young puppies with underdeveloped immune systems and older dogs or dogs with compromised immune capacities.

Valley Fever occurs in many animals, including horses, cattle, deer, elk, apes, monkeys, llamas, tigers, bears, kangaroos, wallabies, etc., but it is most frequently reported in dogs.

Valley Fever Symptoms in Dogs

Valley Fever symptoms in dogs depend on the disease form: primary or disseminated. Primary disease is when the fungal growth is limited to the dog’s lungs.

Symptoms include low-grade, dry, and chronic cough in milder and pneumonia in more severe forms. Local lymph node mineralization, lethargy, poor appetite, weight loss, and fever are seen.

“If the fungus escapes the lung and travels out elsewhere in the body, the infection is said to have disseminated, and the condition is much more serious,” says Wendy Brooks, DVM, in an article for Veterinary Partner.

The bones and joints are the most commonly affected; however, the fungus can also travel to the heart or brain.

Expected symptoms include lameness, back or neck pain, non-healing skin wounds, abscesses, swollen lymph nodes, heart failure, seizures, eye problems, and blindness.

Having a Petcube Pet Camera is helpful for keeping a constant eye on your dog, even when you are not at home.

How Do Dogs Get Valley Fever

Dogs get Valley Fever when they inhale Coccidiodes immitis infectious spores. The fungus has a complex cycle.

In the environment, C. immitis is a mold and goes dormant in the soil when the conditions are not favorable. Rain activates the fungus, which produces filaments with infectious spores.

The spores become airborne when the soil is disturbed, for example, when a dog is digging, construction work is occurring, or strong wind is blowing.

Make sure your dog has a GPS tracker, especially if you live and take walks near risky areas with desert-like climates.

When a dog inhales the spores, they transform into yeast and affect the lungs. The immunity of healthy dogs walls off the yeast.

However, in dogs with underdeveloped, weak, or compromised immune systems, the fungus keeps growing, causing disease.

Valley Fever Treatment for Dogs

The treatment for Valley Fever in dogs is based on antifungals. Commonly used antifungals are fluconazole, itraconazole, and ketoconazole.

The antifungal treatment is long and lasts between six months to a year in most cases. In some dogs, the treatment is life-long to prevent disease relapses.

In the initial treatment phases, the vet may prescribe pain relievers or anti-inflammatories. Dogs with severe clinical signs require nutritional support and fluid therapy.

Natural remedies for Valley Fever in dogs are popular, too, and include immunity boosting and using natural antifungals, like caprylic acid, olive leaf extract with grapefruit seed extract, and oregano oil.

Antifungals alone cost around $200 per month, making Valley Fever an expensive issue. Check out the Petcube Emergency Fund for easier veterinary bill management.

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How to Prevent Valley Fever in Dogs

Valley Fever is not completely preventable, but you can reduce the risk of infection by planting the yard and preventing the dog from doing dust-generating activities.

Plant the ground in outdoor areas around the house. Use deep grass or gravel to control dust formation.

Discourage the dog from digging, and do not let it sniff in rodent holes or stir up dust while playing. Also, keep the dog inside the house during wind storms.

Do not treat the ground against the spores. Since the Coccidiodes immitis spores live 12 inches deep in the soil, treatments are ineffective and can harm the dog instead.


What is the Valley Fever Survival Rate?

The Valley Fever survival rate in dogs is more than 90%. The majority of dogs with Valley Fever respond to treatment and recover. Constant veterinary monitoring is critical during treatment.

Is Valley Fever Contagious in Dogs?

No, Valley Fever is not contagious in dogs. Infections occur only through direct inhalation of the spores and cannot be transmitted from sick to healthy dogs, other pets, or humans.

How to Test for Valley Fever in Dogs?

The Valley Fever test checks the blood for antibodies against the fungus. A positive test means the dog is infected and requires an additional titer test to evaluate the severity of the disease.


Valley Fever is an infectious disease by the fungus Coccidiodes immitis. The fungus is prevalent in sandy areas with desert-like climates.

Dogs get infected when they inhale spores but are not contagious for other pets and humans. Coughing is the standard sign, but other issues like swollen lymph nodes, lameness, seizures, and heart problems are possible, too.

Valley Fever is diagnosed based on blood tests, lung X-rays, and the dog’s traveling history. The treatment includes long-term use of antifungals.

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