Preventative Care@3x

Valley Fever: Is Your Pet at Risk?

Jun 12, 2017 | Arizona Pet Health, Pet Safety, Uncategorized

shutterstock_651663154Valley Fever, or coccidioidomycosis, is an infection of the lungs caused by a fungus that lives in soil. Valley Fever is common in humans, and has been isolated in a variety of mammals, especially dogs.

While the fungal spores remain dormant during dry periods, summer monsoons and rainy weather can awaken them and put you and your pets at risk. When fungal spores are breathed into the lungs, they can grow into ‘spherules’. A healthy immune system will attack and ‘wall off’ the fungus, and no further problems will occur. However, in a compromised immune system, the spherules will continue to grow until they burst, spreading the infection through the body. The spherules then grow in new areas, and repeat the cycle all over again.

The highest incidents of coccidioidomycosis infections occur in Arizona during June and July, and October and November, so here is what you need to know:

RISK FACTORS: Dogs are particularly prone to contracting Valley Fever as they are sniffing the soil and like to dig in the dirt, which means they could easily be exposed to the deadly spores. In rare instances, cats can also contract Valley Fever. The most common symptom in cats is non-healing skin lesions that resemble abscesses, draining tracts, or dermatitis. They can occur in almost any site on the cat’s body, and will often ooze a pale yellow to reddish fluid.

Younger and older animals are at risk. Younger animals are more susceptible to contracting Vally fever as their immune systems are not yet fully developed. Older pets’ immune systems may be weakened or compromised by aging and underlying health conditions.

Many animals will not exhibit any signs of Vally fever, even though they are infected.

DIAGNOSING VALLEY FEVER: Your veterinarian with perform a titer test to look for antibodies. Depending on the severity of infection, they may also perform advanced bloodwork and diagnostic x-rays of the lungs, limbs and other areas of the body. The fungus can also be identified through samples of fluids or tissue from the body.


  • Harsh or dry cough
  • Fever, lack of appetite
  • Lethargy or signs of depression


  • Swollen or painful bones and joints; lameness
  • Persistent fever, lack of appetite
  • Lethargy or signs of depression

PREVENTION & TREATMENT OPTIONS: There is no preventive vaccine for Valley Fever. Keep your pets away from open areas of dirt and dust as much as possible.

Dogs that develop Valley Fever will require a course of treatment with anti fungal medications. The length of treatment depends on the severity of the infection, but most cases will be managed within 6-12 months. Your pet should begin to feel better within 1-2 weeks of starting the anti fungal medications. Over the course of treatment, your vet will perform regular titer testing to determine when medication can safely be discontinued.

If the fungal infection has spread through the body, the dog may need to be on anti fungal medications for life. A small number of dogs will die from Valley Fever – most often those with advanced fungal infection that has spread through the body. The majority of animals will recover with no lasting issues. If you recognize symptoms of Valley Fever, contact your veterinarian immediately.

Disclaimer: Not intended to be a substitute for professional veterinarian advice, diagnosis, or treatment. Always seek the advice of your veterinarian with any questions you may have regarding the medical condition of your pet. If you think your pet has a medical emergency, call or visit your veterinarian or your local veterinary emergency hospital immediately.