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Valley Fever in Dogs
7 Jul, 2020. 0 Comments. Uncategorized. Posted By: swvetsurgery

If you live in Arizona or the Southwest in general, you are probably familiar with the disease called Valley Fever. But are you familiar with how common and severe the disease can be in dogs? We often see some patients with symptoms of lameness due to the disease spreading outside the lungs and affecting the joints and bones. It’s important to understand this disease and do what you can to protect your dogs health.

What is it?

Valley Fever (also called coccidioidomycosis) is a fungus that lives in the soil. These organisms grow in the soil and produce long strands of filaments that are very delicate. When the soil is disturbed (by digging, walking, dust storms, construction, etc.) these strands break into tiny spores that become airborne and can be inhaled. Humans and dogs are most susceptible to contracting the disease, but most mammals, including cats, can be infected.

Once inhaled, the spores enter the lungs and can grow large enough to rupture, releasing hundred of endospores which can then affect tissues, bones, joints, eyes, skin, liver, kidneys, central nervous system and even the cardiovascular system.

In Arizona, it is believed that the highest risk of exposure is during the drier months of June, July, October and November.  The University of Arizona estimates that approximately 6-10% of dogs living in Pima, Pinal, and Maricopa counties will become sick with the disease each year.


When a dog is exposed to a large number of spores, or has a weekend immune system the disease can take hold, and even a small amount of spores can cause the disorder.

Common symptoms include:

  • Coughing
  • Lethargy
  • Fever
  • Poor appetite
  • Weight loss
  • Difficulty breathing

Like mentioned earlier, if the spores have grown and ruptured, the disease can often affect the whole body which can include symptoms of:

  • Lameness
  • Bone swelling/joint enlargement
  • Back or neck pain
  • Seizures and other manifestations of brain swelling
  • Enlarged lymph nodes
  • Skin ulcers and draining sores
  • Eye inflammation

Symptoms may occur weeks, months or even years after exposure to the disease.


The most common test to diagnose the disease is called a Cocci test or Cocci Titer test, otherwise known as a Valley Fever blood test. This test measures the level of antibodies against Coccidiodes within a blood sample. This test is also usually combined with other general blood tests, blood cell counts, and even x-rays to confirm diagnosis. Sometimes x-rays alone can help identify the disease as some dogs show no signs of respiratory symptoms.


Once diagnosed with Valley Fever, your veterinarian will most likely suggest anti-fungal medication for your dog which helps reduce the growth of the Coccidiodes and allows the immune system to help control and hopefully eliminate the infection. The length of time your dog will be on the medication depends on the severity of the disease. Your veterinarian will likely monitor the treatment by testing antibodies every 3 to 4 months until they return to a normal levels. Some dogs may only need it for a short period of time, while other require the medication for the remainder of their life. Relapses can be seen especially if treatment is not followed through completion or is shortened.

Outcome and Prevention

With early diagnosis and intervention, most dogs will recover from the disease. Again, relapses can occur, so it is important to monitor your dog closely and follow your veterinarians recommendations. While Valley Fever is not totally preventable, you can take extra precautions. Keep your pet inside during dust storms, prevent them from digging, and avoid high dust activities.

If you have further questions about this disease, or believe your pet may have Valley Fever, please contact your primary veterinarian for more information.



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