Valley fever infects thousands of people in Kern County each year, but thousands of other cases could be flying under the radar.
Animals, too, can contract the respiratory disease, but the problem remains largely unstudied in Bakersfield, despite the region's status as one of the hottest valley fever regions in the country.
“There is no good information out there about how many animals get valley fever,” said Lisa Shubitz, a research scientist at the Valley Fever Center for Excellence at the University of Arizona. “It’s not reported.”
Shubitz and the Tucson university conducted one of the only studies ever done on valley fever in animals. The university found that from 6 percent to 10 percent of dogs in the three most populous counties of Arizona become sick with valley fever each year.
“That’s a lot of dogs,” she said. “That’s a lot of money.”
The study estimated that Arizonans spend $60 million a year caring for dogs with valley fever.
Experts in Bakersfield know that animals in Kern County also become infected each year, but the extent of the problem is not known.
“California is harder because there is a larger geographic range and it’s a little bit discontinuous,” Shubitz said. “It’s rather more variable than Arizona.”
Dr. Antje Lauer, a professor of microbiology at Cal State Bakersfield, estimated that the rate of dogs infected with valley fever in Bakersfield was slightly less than the Arizona rate. But because no studies have been done on the dog population in the area, she said she couldn’t be sure.
“Kern County is highly endemic, but the areas around Tucson and Phoenix usually have more cases in humans,” she said.
Animals get valley fever the same way humans do — by breathing the spores into their lungs.
Although researchers say dogs make up the majority of valley fever cases in animals, all animals with lungs can contract the infection.
Valley fever, or Coccidioidomycosis, is caused when spores found in dirt become airborne and are inhaled. The infection is endemic to the desert regions of the southwestern United States, including the Central Valley.
The disease causes flu-like symptoms, and there is no vaccine. If left untreated, valley fever can cause a lifetime of health complications.
The Kern County Health Department is currently in the process of tabulating valley fever cases in Kern County in 2018.
In 2017, the department found that 2,929 people had been infected and nine killed from the disease.
Dogs, especially the kind of dogs that root around in the dirt, can be especially susceptible to valley fever.
But canine valley fever is often misdiagnosed — and dogs sometimes instinctively hide that they are sick in the first place.
“When an animal shows that it is sick, the pack will not support it anymore,” Lauer said. “They usually just suck it up for a long, long time before they actually really show they are sick.”
As in human cases, valley fever in dogs can be mistaken for something that it is not.
“There are so many other diseases that animals can get,” Lauer said.
But awareness about valley fever is growing, experts say. And as doctors and veterinarians become more knowledgeable, proper diagnoses should become more common, the researchers say.