Valley Fever (Coccidioidomycosis) is common throughout Arizona and the Southwest, and affects the lungs and respiratory system. It is caused by the fungus Coccidioides, which grows in the soil in low rainfall areas, and regions with high summer temperatures and moderate winter temperatures. These fungal spores become airborne when the soil is disturbed by winds, construction, farming, and other activities, and can occur year-round. Most infections in AZ, however, occur during June and July, and from October to November.

Valley Fever is not a “contagious” disease, and the illness affects both domestic and native animals including dogs, horses, cattle, sheep, burros, coyotes, rodents, bats, and snakes.

Symptoms in Dogs

The most common early symptoms of primary pulmonary Valley Fever in dogs are:

  • coughing
  • fever
  • weight loss
  • lack of appetite
  • lack of energy

Some or all of these symptoms may be present as a result of infection in the lungs. If left untreated, as the infection progresses, dogs can develop pneumonia. As the infections spreads outside of the lungs and into the bones or organs, it can become a disseminated disease, causing lameness and/or death.

Symptoms of disseminated disease can include:

  • lameness or swelling of limbs
  • back or neck pain, with or without weakness/paralysis
  • seizures and other manifestations of brain swelling
  • soft abscess-like swelling under the skin
  • swollen lymph nodes under the chin, in front of the shoulder blades, or behind the stifles
  • non-healing skin ulcerations or draining tracts that ooze fluid
  • eye inflammation with pain or cloudiness
  • unexpected heart failure in a young dog
  • swollen testicles

Dogs with an uncomplicated (mild to moderate) infection that is concentrated in the lungs have the best prognosis for recovery and usually respond the quickest to treatment. More progressive infections require hospitalization and sometimes surgery; however, extreme cases may be fatal.

Medication may be prescribed, such as fluconazole (Diflucan), and in some cases, treatment may be required for life.

If your dog shows signs of Valley Fever, seek veterinary care immediately. The sooner your dog receives treatment, the higher the chance of recovery.

VETMED’s emergency services are available 24 hours a day, 7 days a week. Call (602) 697-4694 to make an appointment or to let us know you’re on the way.