Valley fever infects people, dogs, cats, and livestock across the Southwestern states. Today, our veterinarians in Los Angeles County discuss the causes, signs, and treatment of Valley Fever in pets.

Pets & Valley Fever

Coccidioidomycosis, also known as Valley Fever, desert rheumatism, San Joaquin Valley Fever, and California disease, affects dogs, cats, livestock, and people.

Valley Fever occurs due to the pathogenic fungus Coccidiodes immitis, thriving in specific desert climates and soil. In the United States, Coccidiodes immitis primarily exists in the low desert regions of New Mexico, Texas, California, and Arizona.

Our veterinarians at Animal Hospital of Redondo Beach frequently encounter Valley Fever in both dogs and cats, albeit less commonly in cats. Approximately 1 case in cats is seen for every 50 cases in dogs by our Los Angeles County veterinarians.

It is crucial to promptly seek veterinary assistance upon noticing signs of Valley Fever in your pet. Untreated, the disease can escalate, necessitating urgent medical intervention and potentially leading to fatality.

How Pets Contract Valley Fever

Pets develop Valley Fever when they breathe in Coccidiodes immitis fungal spores. When your dog or cat inhales the spores, they grow into spherules within the pet's lungs.

In dogs and cats with a strong and healthy immune system, the body can typically 'wall off' the spherules preventing symptoms from developing. This means that the pet may have the condition but have no symptoms of Valley Fever, known as asymptomatic.

If your pet is very young, old, or has a compromised immune system, the spherules will likely continue growing until they eventually burst. This releases hundreds of endospores that can spread throughout your pet's lungs and other parts of its body, initiating the cycle anew and exacerbating the condition.

Transmissibility of Valley Fever

Valley Fever in dogs and cats is not contagious between pets and can only be contracted through the inhalation of spores.

Signs & Symptoms of Valley Fever in Dogs & Cats

Although the symptoms of Valley Fever may have some similarities between dogs and cats, there are some key differences.

Signs of Valley Fever in Dogs

In the early stages, when the spherules are contained within the lungs, symptoms of Valley Fever in dogs typically include:

Fever
Lethargy
Decreased appetite
Dry cough

Once the fungal spores spread to other parts of your dog's body, Valley Fever symptoms in dogs may worsen, potentially including:

Painful swollen joints
Eye inflammation
Weight loss
Persistent fever
Blindness

Valley Fever can cause seizures in rare, severe cases if the fungus reaches the brain. If your dog shows symptoms of valley fever, it's crucial to seek veterinary care promptly to prevent serious health complications.

Signs of Valley Fever in Cats

As mentioned earlier, Valley Fever is less common in cats than dogs. When this illness does occur in cats, it tends to be in younger, active outdoor cats since the spores are typically found below the surface but become airborne if that cat digs or during very windy conditions.

Common symptoms of Valley Fever in cats include:

Non-healing skin lesions that look like abscesses or dermatitis and may ooze a pale yellow to reddish fluid
Coughing
Breathing difficulties
Behavioral changes
Limping
Lethargy

Cats with Valley Fever seen by our Los Angeles County vets tend to get sicker than dogs. This may be because detecting when a cat feels unwell can be more challenging, so pet parents begin noticing symptoms only when the condition is more advanced.

Treating Valley Fever in Pets

The typical treatment for Valley Fever in dogs and cats involves administering antifungal medication such as fluconazole or itraconazole. Dogs may additionally receive ketoconazole, although cats generally do not tolerate it well.

Treating Valley Fever in pets is a lengthy process. Most pets will require antifungal medications for a minimum of 6 - 12 months. If the condition persists and spreads throughout the body, there's a chance that your pet may need lifelong medication.

Is Valley Fever Curable in Pets?

The prognosis for pets diagnosed with Valley Fever depends upon the severity of the condition as well as other factors such as your pet's age and overall health.

The Prognosis for Dogs With Valley Fever

When diagnosed and treated early, many dogs recover well from Valley Fever. Dogs diagnosed with Valley Fever after the disease has spread to other parts of the body are more challenging to treat, and in some cases, the disease becomes life-threatening.

The Prognosis for Cats With Valley Fever

When caught early or if your cat only experiences localized symptoms of the skin, the prognosis generally remains good. The prognosis becomes poor if Valley Fever spreads throughout your cat's body. Although treatment may lead to an improvement in your cat's condition, relapse is very common. About 60-90% of cats are estimated to recover well from Valley Fever after receiving treatment.

Valley Fever Prevention

Because the fungus that causes Valley Fever lives in dry, desert soil, the most common places for infection include Arizona, California, Utah, Texas, and Nevada. Luckily, there are several steps you can take to protect yourself and your pet from contracting Valley Fever.

Avoid non-landscaped areas and limit your dog's roaming to well-kept parks.
Take walks in paved areas and keep your dog on a leash.
If your dog likes digging, avoid desert areas.
If your home is in a desert area, keep your pet inside for a reasonable amount of time during the summer.
Learn to recognize the signs of Valley Fever and contact your vet immediately if your dog exhibits any symptoms.

Valley Fever Vaccination

A vaccine is available to immunize your pets against Valley Fever, making it much safer for dogs to roam in yards and other dog-safe outdoor areas.

If you live in an area where the condition is common, it's best to vaccinate your pup on the recommended schedule — likely once or twice a year after the initial dose and booster. The vaccine has minimal side effects, and we hope it will be approved for manufacture within the year.

If you don't live in an area with Valley Fever, it's important to stay aware of any changes that could occur over time. Climate change increases the infection rate, possibly necessitating vaccination in the future.

Note: The advice provided in this post is intended for informational purposes and does not constitute medical advice regarding pets. For an accurate diagnosis of your pet's condition, please make an appointment with your vet.

How to Prevent Valley Fever in Pets