Reese’s first warning sign was an unexplained limp. When the pit bull later coughed through the night and began sleeping alone instead of staying close to her owners, Clarissa Sosin and her husband realized the changes might be connected.
The couple, who live near a wash in central Phoenix, had previously exercised Reese by letting her chase desert cottontails and ground squirrels. They initially suspected that she had strained something during those outings.
A veterinarian considered arthritis and kennel cough the most likely explanations but agreed to draw blood for a valley fever test. The result confirmed the fungal infection, and Reese was prescribed fluconazole for approximately nine months.
Her case illustrates why owners in affected regions should not dismiss a persistent limp, cough or change in activity as an isolated problem. Valley fever can produce respiratory, orthopedic or general signs, and the pattern differs among dogs.
Signs can be subtle or appear unrelated
Dogs contract valley fever by inhaling fungal spores from soil. The University of Arizona’s Valley Fever Center for Excellence estimates that 6% to 10% of dogs in Pima, Pinal and Maricopa counties become sick with it each year.
Soil disturbance can send spores into dust and air. Dr. Lisa Shubitz, a veterinarian and research scientist with the center, said studies have found a relationship between digging and increased disease risk. Sniffing soil and investigating rodent holes can also increase dogs’ opportunities for exposure.
Possible signs include coughing, limping, lameness, back or neck pain, reduced appetite, weight loss, breathing difficulty and lethargy. “Some dogs never cough,” Shubitz said, underscoring why a missing respiratory sign does not rule out the disease.
The infection primarily affects the respiratory system, but it can spread to tissues that include the bones, joints, brain and eyes, according to the UC Davis School of Veterinary Medicine. Seizures or behavioral changes can occur when the brain is involved.
Owners should arrange veterinary evaluation when unexplained coughing, lameness, pain, appetite loss or lethargy persists, particularly after a dog has lived in or traveled through an affected region. Breathing difficulty, seizures or other serious neurologic changes warrant prompt veterinary attention rather than an attempt to assess the condition at home.
Testing requires more than one result
Veterinarians consider a dog’s symptoms, examination findings and exposure or travel history when evaluating possible valley fever. Testing may include antibody blood tests, blood cell counts, serum chemistry panels and X-rays of the chest, bones or joints.
A positive antibody test indicates infection, but it is not always sufficient by itself to establish that valley fever is causing a dog’s illness. Some dogs without symptoms have low antibody titers, while seriously ill dogs can have low or even negative results.
Testing also can be negative early in an infection. The Valley Fever Center’s diagnostic guidance says veterinarians may repeat testing in three to four weeks when suspicion remains. Difficult cases can require examination or culture of tissue or fluid samples, and neurologic signs may lead to advanced imaging.
Owners who live outside an endemic region should tell their veterinarian if a sick dog has traveled through an area where the fungus occurs. That history can help put otherwise vague or persistent signs into context.
Treatment and monitoring can last months
Fluconazole is overwhelmingly the drug of first choice, Shubitz said. Veterinary guidance describes treatment as long term, commonly lasting six to 12 months, although the duration depends on the infection’s severity and the tissues involved.
Shubitz said many owners notice better energy and engagement within the first two weeks in ordinary infections. Improvement does not establish that treatment is complete, however, and owners should not stop medication without their veterinarian’s direction.
Nausea, vomiting, diarrhea and loss of appetite are possible adverse effects of fluconazole. Shubitz checks liver enzymes one month after treatment begins, while ongoing monitoring can include bloodwork, antibody titers and X-rays.
Titers often decline as a dog improves, but some dogs remain positive at a low level. Symptoms and other test results may be more useful than titer changes in dogs that began with low readings, and treatment decisions must be made case by case.
There is no certain way to prevent exposure while living in or visiting an endemic area. The center advises reducing digging, discouraging sniffing in rodent holes, avoiding dust-generating activities and using ground cover to limit yard dust, while recognizing that these steps cannot eliminate risk.
A canine vaccine remains in development and has not been approved by the USDA. Research has produced encouraging protection in a laboratory challenge, but licensing work and remaining safety requirements mean owners should not treat the vaccine as currently available or rely on a projected approval date.
Reese’s limp, cough and withdrawal were not enough for an owner to diagnose valley fever, but together they justified veterinary testing. Attentive owners can identify changes early; determining their cause still requires a veterinarian.
What would you do if your dog were in this situation? Share your thoughts in the comments.
By Sarah Mitchell — 8 years as a local-news reporter covering animal welfare, shelters, neighborhood disputes, and public-safety pet stories.
