UA valley fever research could save sick dogs

Brinkley sits with her foster owner, Michele Ochoa. Photograph by Jules Zappone Arizona Sonora News ©2017.

Brinkley is only 1 1/2 years old. She takes six medications a day. One combats the infection in her bones. Three suppress her pain. One supplements her joints, and the last is an antibiotic that fights her additional health threats.

Brinkley suffers from a severe case of valley fever, a disease that is crippling dogs all over Arizona.

There is nothing that could have prevented Brinkley from contracting the disease, but research at the University of Arizona could change that, with a vaccine that would eliminate the threat of valley fever in dogs, possibly within the next five years.

“We’ve had some good luck recently,” said John Galgiani, Director of the UA Valley Fever Center for Excellence. “We have a (potential) vaccine that has been very productive in mice.”

Researcher and veterinarian Lisa Shubitz said vaccine tests on dogs should begin within the next year.

The annual number of Valley Fever cases reported in Arizona and California. Graph prepared by the Valley Fever Center for Excellence ©2016.

Valley fever is a respiratory infection caused by the inhalation of a fungus found in the soil of dry, desert areas with high summer temperatures and moderate winter temperatures. Primary exposure to the fungus comes from spores found in dust particles in the air. Two-thirds of the human and animal valley fever cases in the U.S. occur in Arizona, according to the UA Valley Fever Center.

“This is a disease with a major impact,”  Shubitz said.

The best situation for treating the disease is to prevent it. The center has been working with a potential vaccine for the past five years and is contracted with a pharmaceutical company looking to patent and help move the vaccine to market. With this partnership and a $4.8 million grant from the National Institute of Health, the center is one step closer to a successful vaccine.

The potential vaccine eliminates the fungus’ ability to cause disease. Mice injected with the vaccine did not get sick when exposed to the fungal spores that cause valley fever.

Brinkley is just one of many dogs in the Southwest region of the United States who could have benefited from a preventative vaccine. UA researchers estimate nearly 10 percent of dogs living in Pima, Pinal and Maricopa counties are diagnosed with valley fever each year. The percentage of infection in those counties is much higher for dogs than humans — only 3 percent of people from those counties are diagnosed each year.

Valley fever can be contracted by both humans and animals. The disease is usually treatable in humans with just a few months of anti-fungal medication. The most common symptoms of valley fever in humans are fatigue, cough, fever, profuse sweating at night, loss of appetite, chest pain and generalized muscle and joint aches.

The average cost to treat valley fever in dogs.

In animals, specifically dogs, there are two degrees of valley fever cases: uncomplicated and complicated. An uncomplicated case affects a dog’s lungs and bones, and can cause coughing, fever, weight loss, lack of appetite and lack of energy. According to a 2005 Valley Fever Center study, 90 percent of valley fever cases — when caught early on — were successfully treated.

“However, successful treatment often means the dog will be on medication for the remainder of its life,” Shubitz said. “It’s a less than ideal situation.”

A complicated case is primarily caused by a late diagnosis and leads to more severe symptoms. Often the dog is not getting better on medication — possibly getting worse — and the disease has started to move around the dog’s body. Complicated cases can lead to death.

After a dog tests positive for valley fever, the lab performs a secondary assessment called a titer. The titer assesses the severity of the disease by measuring how much antibody the dog is making to combat the fungus; a higher titer means a more severe case. Brinkley’s test results showed her titer to be above the maximum score, meaning her valley fever is severe.

“She has no muscle or fat. All that’s from the valley fever,” said Michele Ochoa, Brinkley’s foster owner. “She’s so emaciated, it’s impossible to tell what breed of dog she is.”

Ochoa says Brinkley seems to be on the mend these days. She’s livelier and she has more energy. Ochoa is hopeful, but it will be months before she’ll know for sure that Brinkley’s medication is working.

Jules Zappone is a reporter for Arizona Sonora News, a service from the School of Journalism with the University of Arizona. Contact her at jzappone@email.arizona.edu.

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