The dizziness, double vision, vomiting and other symptoms persisted and were unlike anything he had ever experienced.

Local emergency room doctors dismissed it as the flu. But within a couple weeks, Shaw was nearly blind and unable to walk.

Alarmed, his wife took him to the University of Utah Medical Center, where doctors ran dozens of tests, including several spinal taps and a biopsy of his brain tissue.

Shaw was eventually diagnosed with meningoencephalopathy, a serious neurological disorder that caused swelling in his brain and spinal cord.

He also tested positive for Q fever and Chlamydia pneumonia, two zoonotic diseases.

Zoonotic diseases are those that can be shared between humans and vertebrate animals such as livestock, and they’re far more common than many people realize.

Shaw was hospitalized a total of 5 1/2 months and spent much of that time on a ventilator. He suffered three separate bouts of pneumonia.

“He couldn’t move or feel any of his limbs for a month,” says his wife, Jalyn Shaw.

Family members trace the mysterious illness to a cold day in mid-February 2011 when Shaw assisted a 7-year-old cow with a difficult birth at the ranch near Dietrich, Idaho.

He had placed the shivering, sick calf in the pickup cab with him and cranked up the heater while he ran some errands around town.

The intervention was for naught. The calf later died.

Nearly a year later, Shaw, 37, was still in a wheelchair. The disease paralyzed one side of his vocal chords, so he has difficulty speaking.

His prognosis is uncertain. Only time will tell how much of his motor skills will return.

Doctors told Jalyn Shaw that her husband likely developed the debilitating neurological disorder as a reaction to Chlamydia pneumonia.

“They said (the pathogen) could have been in the placenta, and turning the heater on in the cab circulated it in the air; he apparently breathed it in,” she says.

While Shaw’s condition appears to be a rare complication from a zoonotic disease, it’s a reminder that working with livestock carries risk.

Farmers and ranchers should be aware of situations where zoonotic pathogens might be lurking and to take appropriate precautions, says David Van Metre, a professor at Colorado State University’s College of Veterinary Medicine and Biomedical Sciences.

Here are some situations that producers should consider as higher risk for encountering potential zoonotic disease agents:

• Any obstetrical assistance, even if the calving is uneventful
• Abortions — many of the bacteria that cause abortion in livestock can cause zoonoses. The affected livestock can shed massive numbers of potentially harmful agents.
• Diarrhea in calves or adult cattle
• Unfamiliar signs of illness and/or unexplained death in livestock
• Any kind of progressive neurological disease in livestock

“We tend to become even more on the alert about obstetrical interventions when we have abortions, still-births or the birth of weak calves,” Van Metre says. “Then the caution flag goes up even higher.”

“While many may consider these diseases to be uncommon, the truth is, well over half of all known infectious diseases of humans are zoonoses,” Van Metre says.

Most are not nearly as serious as the debilitating disorder that struck Acey Shaw.

Most cases of Q fever, for instance, go entirely unnoticed by those infected.

“The majority of Q fever infections in humans are asymptomatic,” Van Metre says. “People become infected, they mount an antibody response, and they don’t even know that it happened.”

Zoonotic diseases are transmitted by bacteria, viruses or parasites.

Some of the more common disease agents that might be transmitted from beef cattle to ranchers and their family members include Cryptosporidium (a parasite) and bacteria such as Salmonella, Leptospira and Coxiella, Van Metre says.

Occasionally being around sick livestock is part of the job for ranchers, and some may figure that they’re probably immune after years of exposure.

But what ranchers often fail to realize is that just like in cattle, stress and age and other diseases can impair their immunity too.

“The immunity that these ranchers had when they were 30 years old is not the same immunity that they have when they are 55 or 65,” he says.

Provide prevention

The first line of defense against zoonotic disease is a solid herd health program, Van Metre says.

Cattle that are well fed and well protected from preventable diseases are less likely to develop infectious diseases of any kind.

Also consider that most physicians aren’t accustomed to diagnosing and treating zoonotic diseases.

“Ranchers and veterinarians represent well under 1 percent of the general U.S. population,” Van Metre says.

“Should you become ill, make sure that your physician clearly understands your occupation and your daily exposure to livestock, and encourage your physician to contact your veterinarian to discuss your potential for recent exposure to zoonotic agents,” Van Metre says.

Third, producers should wash their hands with soap and water after handling livestock, particularly before eating and drinking, he says.

Finally, producers should consider the potential for shoes and clothing to be contaminated with infectious agents.

Whenever possible, change out of your work clothes before entering your home or someone else’s, particularly after encountering higher-risk situations, he says.

Van Metre isn’t sure whether zoonotic disease is on the rise, but he is certain that we are all becoming more aware of the risk.

“I don’t think we are seeing an increase in the prevalence of these diseases. We are seeing an increase in the awareness, and that’s a good thing so that we can catch these types of events earlier,” he says.