How to Spot Valley Fever in Dogs

How to Spot Valley Fever in Dogs

Author WDF Staff


There are different diseases, parasites, and fungi that can infect our dogs. It might seem that dogs can get sick at every turn. It is best to be prepared and know what might cause health issues for your dog, and one of these things is called valley fever. If you live in an area where valley fever is common, here are a few things you should know about it.

What is valley fever?

Valley fever has different names. The scientific name is coccidioidomycosis, but it is also known as desert rheumatism, California disease, or San Joaquin valley fever. This is a disease caused by the Coccidiodes immitis fungus that has a complex life cycle. Dogs are not the only ones at risk of this disease. It is relatively common in humans, horses, monkeys, kangaroos, deer, elk, tigers, bears, badgers, mules, llamas, apes, wallabies, otters, fish, and marine mammals.

Where is valley fever common?

One of the things that make valley fever so successful is the fungus’ adaptability. The fungus adapted to thrive in the dry, desert areas, so the disease is most common in;

  • Arizona
  • California
  • Nevada
  • New Mexico
  • Texas
  • Utah
  • Northwestern Mexico
  • Central America
  • South America

How can my dog get valley fever?

One of the most important things dog owners need to know about valley fever is the way it spreads. If they know how the disease spreads, chances are that they might prevent their dogs from getting it. To fully understand how dogs get it, we first need to understand the fungus’ life cycle.

The fungus lives on the ground as mold. When the weather is warm and dry for a long time, the mold can go dormant in the soil. It will stay like that for long periods. As soon as the rain comes, the mold springs back to life. The fungus starts growing again and will produce long filaments of mold. These filaments produce infectious spores that become airborne as soon as they are disturbed by the wind or accidental contact. As soon as the infectious spores are inhaled, they transform into a yeast-like organism that can infect the new host’s lungs.

In short - the dog can get infected with valley fever by inhaling the fungus’ infectious spores. Dogs like to dig and sniff the ground, which makes them come close to the infectious spores.

What are the symptoms of valley fever?

Since the disease is spread through inhaling infectious spores, you can probably imagine that the first symptoms will be respiratory. When the spores enter the dog’s lungs, they will develop into something called spherules. Usually, a healthy dog’s immune system will isolate these spherules and will not allow them to cause much trouble. However, in dogs with a weaker or compromised immune system, severe symptoms can occur. The symptoms will be different based on the two versions of the disease valley fever causes.

Primary disease

Primary valley fever is contained in the dog’s lungs. This usually happens in dogs with healthy immune systems. The disease was controlled and kept only in the primary infection area. One of the worst things about this disease is that it can happen anywhere from 3 weeks to 3 years after the dog inhaled the infectious spores. The most common symptoms of primary valley fever disease are a dry cough, fever, lack of appetite, depression, and lethargy.

Disseminated disease

Disseminated disease can happen when a dog has a compromised immune system which allows spherules to grow and burst. When spherules burst, they “pour” more infectious spores in the dog’s body, allowing the fungus to travel the body and infect other organs. The first thing this version of disease will infect after the dog’s lungs are joints and bones.

There will be quite a bit of swelling in the dog’s joints. Other disseminated valley fever disease symptoms include constant fever, lack of appetite, depression, lethargy, and loss of body weight. In some cases, the fungus can infect the brain and eyes, causing blindness and seizures.

IMPORTANT NOTICE: Valley fever can sound dangerous, but the good news is that it is not transferrable. If one of your dogs caught it, they could not transfer it to you or your other pets.

How is valley fever treated?

Most dog owners notice something weird is going on with their dog, and they take them to their vet. The treatment can start once the vet performs titer tests, x-rays of the infected lungs, or analyzes the infected body fluids or tissue. The bad news is that the treatment is long-lasting. The vet will give your dog antifungal medications, and the usual treatment duration is between 6 and 12 months.

Another piece of bad news is that the infection can spread to the dog’s central nervous system. If that is the case, chances are your dog will need to take antifungal medications for the rest of their life.

VET ADVICE: Valley fever can be challenging to resolve. However, even though the treatment is lengthy, it is fairly effective. The good news is that valley fever is extremely rare in North America.

World Dog Finder team

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