Valley Fever in Dogs

In November of 2015, Marlowe tested positive for Valley Fever after being sick for a couple weeks.  Valley Fever is very difficult to diagnose in humans, dogs, and cats because the symptoms are only the basics: fever, lack of appetite, lethargy, and a dry cough.  The common cold has the same symptoms in some cases.

How Do Dogs Get Valley Fever?

Valley Fever comes from the spores of a fungus that grows in the ground.  In humans, there is usually something that disturbs the ground and kicks the spores up into the air.  For dogs, the coccidioides fungi and spores simply have to be exposed because dogs naturally sniff the ground.  They also sniff shoes, pants, tools, tires, and many other things that come in contact with the soil and could be contaminated with the spores of the fungus.  Once a dog sniffs the spores and gets them in their lungs, it’s pretty much a shut case.  The spores settle into the lungs and grow.

How Do I Know if My Dog Has Valley Fever?

Because the symptoms mimic many other illnesses, a dog really will have to be checked by a veterinarian to confirm Valley Fever.  There are three things a veterinarian can check: white blood cell count, x-ray imaging, and a Titer test.

White Blood Cells in Diagnosing  Valley Fever in Dogs

My vet kept an eye on the white blood cells at every checkup to monitor Marlowe’s illness. There are different types of white blood cells, each with its own function in protecting a dog from infection. A differential reading will show your vet which infection group is fighting something off and I know my vet was hoping it wasn’t going to be Valley Fever.  The antibodies specific to fighting Valley Fever are called tococcidioides.

X-Ray Diagnosis of Valley Fever in Dogs

My veterinarian listened to Marlowe’s cough and lungs very carefully before deciding on the expense of the x-rays.  I love that my vet never starts with expensive testing.  I think he knows that whatever he suggests will result in me handing over my credit card, so it’s never a ‘suggestion’ with me when he talks about a test.  All of my animals receive 5-star medical care and I wouldn’t allow them to have anything less.  The x-rays would show if there was anything growing in the lungs or any fluid.  Marlowe’s cough was dry, so we weren’t expecting any fluid and we could only hope it wasn’t anything growing, but we had to look.  X-Rays are cheaper than the Titer test, so it’s the better place to start and the Titer test takes a long time to get results whereas the x-ray is instant.

Unfortunately, Marlowe’s x-ray didn’t look good.  There should be black all around his heart.  Instead, there were white tendrils centered at the end of his trachea.

Titer Test – The Final Word in Diagnosing Valley Fever in Dogs

Complement Fixation Titer (CFT) is a common test for coccidioides antibodies in the blood. There are two types of antibodies in the CFT test: Immunoglobulin M (IgM) which show up during the first 6 months, and Immunoglobulin G (IgG) which are what get checked thereafter.  Big words aside, my veterinarian took a sample of Marlowe’s blood and had to send it out for testing, which took over a week to process.  My recollection was that it was closer to two weeks.  They also had him breathe into a plastic bag for another sample.  When I got the call with the Titer results, I was lucky to be at a friend’s house because I felt like the world fell out from under my feet.  His levels were almost 140 of something, which was over moderate and pushing high.  So even though I’m that worrisome mother that took my pup in at the first sign that something was wrong and thereby “caught it earlier than most,” he was very, very sick.

How is Valley Fever Treated in Dogs?

It’s important to note that Valley Fever is manageable, not curable.  Marlowe will be subjected to a Titer test every 6 months to check his levels (there is some great information on Titer tests and levels in humans at