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Canine Valley Fever

Originally written by Catherine A. Bono

Medically reviewed and updated by Janice Jones, former veterinary technician

Last updated: January 2026

Canine Valley Fever, medically known as coccidioidomycosis, is a fungal infection caused by inhaling spores found in the soil of certain warm, dry regions.

The disease is most commonly seen in the southwestern United States, including Arizona and California, as well as in parts of Mexico.

While exposure to Valley Fever spores is common, most dogs that inhale the fungus never become seriously ill. When illness does occur, early diagnosis and veterinary care greatly improve outcomes.

This page explains how dogs contract Valley Fever, which symptoms require attention, how the disease is diagnosed, and what treatment and recovery typically involve.

How Does My Dog Get Canine Valley Fever?

Valley Fever develops when dogs inhale fungal spores released from disturbed soil. These spores become airborne during activities such as construction, digging, windstorms, or other ground disruption.

The spores are extremely small and cannot be seen or avoided easily. Dogs do not contract Valley Fever from other animals; it is acquired directly from the environment.

Dogs that spend significant time outdoors in endemic regions may be at higher risk of exposure, but indoor dogs can also be affected.

Two main forms of Canine Valley Fever

Primary – The respiratory form, which only infects the lungs and respiratory system. If left untreated, dog Valley Fever may cause pneumonia.

Other signs of primary dog Valley Fever include coughing and fever.

Disseminated Valley Fever occurs when the infection spreads beyond the lungs to other parts of the body. This form requires prompt veterinary care and long-term treatment, but many dogs respond well when therapy is started early.

Symptoms of Canine Valley Fever

Many dogs exposed to Valley Fever never develop noticeable symptoms. When symptoms do occur, they may begin mildly and progress over time.

Any dog living in or traveling through endemic areas who develops persistent respiratory symptoms should be evaluated by a veterinarian.

Canine Valley Fever Symptoms

Symptoms vary depending on whether the infection remains in the lungs or spreads to other areas of the body.

Symptoms may be mild at first but may progress as the infection spreads or worsens. Keep an eye out for the following Valley Fever in dogs symptoms:

• Difficulty breathing
• Coughing that starts out dry and may become moist
• Weight loss
• Weakness and lethargy
• Loss of appetite
• Fever

As this infection spreads or becomes disseminated, symptoms may worsen.

Oftentimes, Valley Fever in dogs symptoms worsen after the infection has been present for more than 4 months. These symptoms include:

• Diarrhea
• Vomiting
• Extreme and recurring fevers
• Loss of vision
• Skin sores known as ulcers
• Swollen joints, especially around the back and neck
• Limb Lameness
• A severe cough may contain mucus
• Seizures
• Weeping eyes

Some dogs are more at risk of contracting Canine Valley Fever than others.

Dogs at higher risk for illness include those with weakened immune systems, young puppies, senior dogs, and dogs with existing health conditions.

Breeds such as Boxers, Beagles, Cocker Spaniels, and Doberman Pinschers are known to become ill from Valley Fever more than other breeds as well.

Treatment for Canine Valley Fever

Some dogs experience mild illness and may not require long-term antifungal therapy. However, any dog showing symptoms should be evaluated by a veterinarian.

However, when a dog does become ill from Valley Fever, it can become very serious.

To seek Valley Fever in dogs treatment, you will need to keep an eye on symptoms and bring your dog to the veterinarian as soon as symptoms become present.

Your veterinarian will diagnose dog Valley Fever a couple different ways. Your vet will perform a physical exam to check the joints and muscles.

Blood tests may be required if the infection has spread through the blood system. X-rays and radiographs may also be performed to check the lungs and joints.

Once your veterinarian has diagnosed dog Valley Fever, treatment will begin right away.

If your dog is quickly and properly diagnosed, treatment is usually very successful. However, sometimes treatment can take up to a year to complete.

The most important part of treatment is to ensure that the fungal organisms do not continue to multiple and to prevent them from spreading to other areas of the body, otherwise known as becoming disseminated.

Some treatments for Valley Fever in dogs include:

Anti-fungal medication – Oral anti-fungal medications are the most effective form of treatment.

Often times, anti-fungal medications must be given twice a day for 6 months up to a year. In severe cases, sometimes even longer.

Anti-fungal medications require close monitoring and frequent blood testing, as some medications can create serious illnesses in dogs.

Cough medication – If your dog has a severe cough, your veterinarian may prescribe a mild cough suppressant.

Diet – Some dogs may lose their appetite when they are infected with dog Valley Fever. In this case, home cooked meals, hand-feeding or even feeding tubes may be required to ensure your dog is eating enough food. IV fluids may be given as well to ensure hydration.

Antibiotics – Your veterinarian may prescribe antibiotics to ensure a secondary illness does not interfere with treatment for dog Valley Fever.

Pain medication – If your dog has a severe fever, or his joints are sore, your veterinarian may prescribe pain medication or anti-inflammatory medications to ease swelling and pain.

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The respiratory form of Valley Fever generally carries a better prognosis than disseminated disease. With appropriate treatment and monitoring, many dogs recover and return to a good quality of life.

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