Skip to Content

The Weekly News Source for Wyoming's Ranchers, Farmers and AgriBusiness Community

UW Research

by Wyoming Livestock Roundup

Vet student helps unravel BRD causes

Samantha Haller, a second-year vet student from Cheyenne, graduated with a degree in physiology from the University of Wyoming (UW) in 2017 and attended the College of Veterinary Medicine at Washington State University. 

This summer, Haller was accepted into the diagnostic externship program in the UW Department of Veterinary Sciences and has spent the last few months helping combat the number one cause of illness and death in cattle worldwide, Bovine Respiratory Disease (BRD).

BRD impacts

According to the Beef Cattle Research Council, BRD accounts for 65 to 80 percent of sickness and 45 to 75 percent of deaths in feedlots, costing the operations billions of dollars a year.

Donal O’Toole, a professor in the department who heads the diagnostic externship program at UW, stated BRD is the most important single disease entity worldwide in terms of cattle illness and deaths.

Haller explained, “Scientists have figured out a lot about the main infectious players, but now there’s some bacteria that are maybe less common or a little bit harder to diagnose that are involved.”

BRD research

Therefore, Haller has spent her summer researching the deadly disease. She noted her study is looking at the roles of Histophilus somni and Mycoplasma bovis in past cases.

“Professor O’Toole and Associate Professor Kerry Sondgeroth have found both in more sub-acute to chronic bovine pneumonias, and they think it’s probably pretty under diagnosed,” explained Haller. “The point of my project is to go back and look through a lot of recently archived bovine pneumonia cases and establish whether one or both agents were present.”

Haller further explained she is using two methods to study these cases of pneumonia, including polymerase chain reaction (PCR) and immunohistochemistry.

“Preserved tissue is archived for 10 years after a diagnostic case is reported.

Histophilus somni and Mycoplasma bovis have been challenging to rank in terms of their importance in pneumonia,” explained O’Toole. “For technical reasons, they can be missed in routine diagnostic workups.”

O’Toole then noted their testing should determine if standard methods are sensitive enough to accurately identify all of the major infectious causes of pneumonia in individual animals.

 “Wyoming State Veterinary Laboratory clients, including veterinarians and producers, need this information to be complete and accurate to inform their decisions about vaccination and treatment,” he stated.


O’Toole noted the UW study would be impossible without support from the Kurt Swanson Bucholz Veterinary Science Training Fund.

“It requires someone like Ms. Haller who has a block of time and good hands to push it through,” he said.

He noted the fund provided more than $13,500 in scholarship and for research supplies.

“Ms. Haller has done well. The quality of her work has been excellent,” O’Toole said. “She picked up the technical work surprisingly fast, under the supervision of staff in bacteriology and histology.”

 “Working with the pathologists here has been great, and they’re all such great teachers. I’ve gotten a lot of hands-on experience,” said Haller.

Hannah Bugas is the managing editor for the Wyoming Livestock Roundup. Send comments on this article to

Back to top