Texas A&M Researchers Investigate Salmonella Transmission To Protect Veterinary Hospitals
Story by Courtney Price, VMBS Marketing & Communications
Researchers at the Texas A&M College of Veterinary Medicine & Biomedical Sciences (VMBS) understand that it takes a team effort to solve complex problems.
As such, veterinarians and scientists from the VMBS’ College Station campus are collaborating with their colleagues at the Veterinary Education, Research, & Outreach (VERO) campus in Canyon to tackle global challenges.
Using advanced techniques, they study problems such as bovine respiratory disease and antimicrobial resistance, which threaten animal well-being and food production safety.
These researchers are also leaders in studying salmonella, a leading cause of foodborne illness, hospitalizations, and deaths in both people and animals. It is also one of the most common reasons large animal veterinary hospitals are forced to close temporarily until the hospital environment is sanitized and the bacteria are eliminated.
Researchers at VMBS’ Large Animal Teaching Hospital (LATH) and VERO, along with other VMBS departments and universities, are conducting a series of studies aimed at protecting veterinary hospitals from salmonella outbreaks by developing advanced infection control measures and providing resources to ensure their safety and success.
“Large animal veterinarians and hospitals serve a wide range of patients, including horses and food and fiber animals,” said Dr. Jennifer Schleining, head of the VMBS’ Large Animal Clinical Sciences (VLCS) department. “The research being conducted at VERO — including on salmonella — has the potential to impact owners’ relationships with companion animals; the global supply of meat, wool, and dairy; and the well-being of millions of animals.”
Protecting Hospitals From Salmonella
One key to preventing salmonella outbreaks at veterinary hospitals is identifying which patients are most likely to shed the bacteria before it spreads to other patients.
Infected animals can shed large numbers of bacteria in their manure — even if they appear healthy — which can easily spread to surfaces, tools, other animals, and people.
“Salmonella can be very difficult to manage because of the high potential for exposure around infected animals, and it doesn’t take very many bacteria to cause an infection in susceptible animals and people,” said Dr. Paul Morley, the Sally Rau MacIntosh professor of Strategic Initiatives in VLCS and director of research at VERO.
Even with strict infection controls, hospitals can be vulnerable to salmonella outbreaks because they are inherently places where animals with weakened immune systems are cared for.
For these reasons, veterinary hospitals implement a whole host of methods to prevent the bacteria from spreading.
“Infection control is important because it’s a vital part of delivering the very best patient care that is possible,” Morley said. “It’s all about preventing animals from getting more sick after they enter a hospital, as well as protecting the people who work with them.
“Once you know that an animal has an increased risk of a salmonella infection, you can take more precautions. You can keep them segregated from other animals, give more attention to disinfecting surfaces and tools, and wear barrier gowns and other personal protective equipment to keep the bacteria contained,” he said. “We currently need more research to help us understand shedding patterns so we can quickly identify high-risk patients — this is an important goal of our current collaborations at Texas A&M.”
Salmonella can also impact people working at veterinary hospitals and animal owners.
“Veterinarians are always very concerned about protecting people from zoonotic diseases. For salmonella, we are concerned with exposures that can occur while caring for infected animals, but we also want to eliminate the potential of taking salmonella home to our families or pets through contamination of shoes or clothing,” Morley said. “Salmonella transmission can impact many different lives, which is why we work so hard to stop it.”
Using Patterns To Prevent Outbreaks
While hospitals like the LATH are already using state-of-the-art infection control methods, constant awareness is needed to stay on top of potential problems. That’s why VERO researchers are collaborating with the LATH’s Food Animal Medicine and Surgery Service to study how common it is for patients to have salmonella when they arrive for treatment.
The study, funded by an internal grant and conducted by second-year resident Dr. Elizabeth Rumfola, involves collecting samples from 600 animals to be tested with help from Morley and Dr. Sara Lawhon, a VMBS professor and director of the Clinical Microbiology Laboratory, which serves both hospitals that comprise Texas A&M’s Veterinary Medical Teaching Hospital.
“This project is serving many purposes,” said Dr. Shannon Reed, a VLCS clinical associate professor of food animal medicine and surgery. “It’s helping us look at the animal population coming here to see how many are infected with salmonella when they arrive; it helps us refine our biosecurity protocols and better understand what we should do to protect our patients; and it’s also allowing us to support Dr. Rumfola, who will get to use this study to meet the publication requirements set by the American College of Veterinary Internal Medicine.”
The project will also fill a gap in research on hospital facilities that cater to a diverse range of species.
“Previous studies on this topic have focused on salmonella transmission in horses, but our Food Animal Medicine and Surgery Service sees a minimum of five different species each year. Having these data will allow us to understand how to be most effective in a service area that works with so many different species simultaneously,” she said.
Through their research, they also hope to understand why animals in Texas — and anywhere with a southern climate — seem to be more susceptible to salmonella.
“Texas is unique,” Reed said. “This project will help us understand how environmental conditions may influence the levels of salmonella that we detect. We’re collecting samples over an entire year to see if there are differences that correspond to seasonal patterns. Depending on what we learn, there may be an opportunity to share data with other veterinary hospitals to also help them prevent outbreaks.”
Detecting Small (But Mighty) Bacteria
In another project, VERO researchers are using advanced techniques to develop new diagnostics that can help hospitals identify infected patients with greater speed and accuracy; this will help hospitals determine whether an infected patient arrived already carrying salmonella or became infected at the hospital, indicating potential for an outbreak.
For this project, funded by the National Cattlemen’s Beef Association, Morley is working alongside fellow VERO faculty members Dr. Lee Pinnell and Dr. Robert Valeris-Chacin to improve methods for identifying different strains of salmonella in cattle.
“Because it doesn’t take very many bacteria to cause an infection, we need the ability to detect very small amounts in the environment, because they still have the potential to cause infections,” Morley said.
“One way that we do this is with polymerase chain reaction (PCR) tests, which are able to detect salmonella using even small amounts of DNA,” he said. “But PCR isn’t instantaneous — it can take two to four days to get a result, which slows down our ability to address the source of the problem.”
Salmonella researchers must then use other techniques to differentiate strains.
“If we can tell that two infected patients carry different strains of salmonella, then we know that they likely arrived with unrelated infections,” he said.
“These more sensitive techniques are not easy to perform, and they are more expensive than other methods, which is one reason that salmonella research isn’t more common,” Morley said. “Our team is very fortunate to have the resources to use these newer, advanced techniques at VERO.
“We’re also looking at whether horses can be infected with multiple strains of salmonella simultaneously,” Morley said regarding another project being conducted with the help of doctoral student Brennon Hunt, VERO laboratory manager Cory Wolfe, postdoctoral researcher Dr. Enrique Doster, and Pinnell.
Morley is also collaborating with Dr. Brandy Burgess at the University of Georgia on a project enrolling horses from across the country to study how long they continue to shed salmonella after infection.
“We believe our findings will help us improve infection control guidelines to protect people and other horses,” Morley said.
Leading The Way In Disease Control
The work of VMBS researchers and their collaborators will not only assist LATH patients but also benefit patients at other veterinary hospitals by keeping veterinarians informed about the best practices for infection control.
“Throughout my career, I have helped develop infection control policies and procedures that have become the standard for many other facilities,” Morley said. “At VERO, we continue to collaborate and consult with other veterinary hospitals to improve programs that control infectious disease problems in veterinary hospitals, creating opportunities for optimizing care of their patients.
“By raising the standards of infection control across the country, we’re helping to keep all hospital patients healthy, not just those that can be exposed to salmonella,” he said.
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Note: This story originally appeared in the Summer 2025 issue of VMBS Today.
For more information about the Texas A&M College of Veterinary Medicine & Biomedical Sciences, please visit our website at vetmed.tamu.edu or join us on Facebook, Instagram, and Twitter.
Contact Information: Jennifer Gauntt, Director of VMBS Communications, Texas A&M College of Veterinary Medicine & Biomedical Sciences, jgauntt@cvm.tamu.edu, 979-862-4216
