Veterinary Science: In-Depth Description

Image Credit: Scientific Frontline / stock image

Veterinary Science is the branch of medicine and science concerned with the prevention, control, diagnosis, and treatment of diseases, disorders, and injuries in animals. Beyond clinical care, the field encompasses animal rearing, husbandry, breeding, research on nutrition, and product development. Its primary goals are to safeguard animal health, relieve animal suffering, conserve animal resources, promote public health through the control of zoonotic diseases, and advance medical knowledge through comparative medicine.

Escherichia albertii: The still unfolding journey of a misdiagnosed pathogen

Animal to human bacteria pathways
Escherichia albertii is primarily found in mammals and birds, suggesting it is a novel zoonotic pathogen.
Image Credit: Osaka Metropolitan University

Escherichia albertii, initially identified as Hafnia alvei, by the commercial identification biochemical strip, API 20E, was isolated from an infant with diarrhea in Bangladesh in 1989. However, this bacterium was later renamed as a novel species, E. albertii because of its similarities in biochemical and genetic properties to the genus Escherichia, but different from those of any known species in the genus. E. albertii possesses many pathogenic attributes including a key one, which is the ability to produce attaching and effacing (A/E) lesions in the intestinal mucosa mediated by genes on a 35-kb pathogenicity island called the locus of enterocyte effacement. Therefore, it is a member of the family of A/E pathogens.

Novel Kirkovirus May Be Associated with Colitis in Horses

Photo Credit: Nick Page

In a pilot study, researchers from North Carolina State University have found a novel kirkovirus that may be associated with colitis – and potentially small colon impactions – in horses. The study could offer a route to new therapies for horses with colitis symptoms from unknown causes.

“Horses are uniquely susceptible to colitis, and the structure of their gastrointestinal tracts amplify the negative effects,” says Lilly Haywood, Ph.D. student in NC State’s College of Veterinary Medicine. “Horses have very large colons and cecums to facilitate water absorption, so when these structures become inflamed the horses dehydrate quickly. And their large intestines contain a lot of bacteria, so inflammation can lead to those bacteria entering the bloodstream and causing sepsis.” Haywood is first author of the study.

“The other issue when dealing with colitis in horses is that in more than 50% of cases we are unable to find the cause,” says Breanna Sheahan, assistant professor of equine medicine at NC State and corresponding author of the study. “We suspected there might be another viral cause for some of these cases, so we started looking for one.”

Receptors in mammary glands make livestock and humans inviting hosts for avian flu

Microscope-captured images of a mammary gland of a pig show the presence of influenza receptors. In the image on the left, receptors for avian influenza A are colored orange. In the image on the right, receptors for the type of influenza A that typically infects mammals are purple.
Image Credit: Dr. Tyler Harm/Iowa State University

An ongoing outbreak of highly pathogenic avian influenza has affected more than 184 million domestic poultry since 2022 and, since making the leap to dairy cattle in spring 2024, more than 1,000 milking cow herds. 

A new study led by Iowa State University researchers shows that the mammary glands of several other production animals – including pigs, sheep, goats, beef cattle and alpacas – are biologically suitable to harbor avian influenza, due to high levels of sialic acids.

“The main thing we wanted to understand in this study is whether there is potential for transmission among these other domestic mammals and humans, and it looks like there is,” said Rahul Nelli, the study’s lead author and a research assistant professor of veterinary diagnostic and production animal medicine.

Probiotics and Prebiotics Offer Safer Alternatives to Antibiotics in Animal Agriculture

Livestock producers face multiple challenges when adopting probiotics and prebiotics, from selecting effective microbial strains to ensuring product safety, viability, and cost efficiency.
Photo Credit: Joachim Süß

Probiotics, prebiotics, and synbiotics enhance livestock gut health, immunity, and growth while reducing dependence on antibiotics 

A new study by researchers at Shinshu University highlights the essential role of gut microbiota in livestock health and productivity. The researchers show how probiotics, prebiotics, and synbiotics can safely enhance growth and immunity, and balance the growth of intestinal microbes, offering practical alternatives to antibiotics. As global restrictions on antibiotic use intensify, the findings support sustainable livestock management and contribute to reducing antimicrobial resistance risks. 

New stem cell medium creates contracting canine heart muscle cells

Canine iPS cells cultured in a newly developed medium successfully differentiated into functional cardiomyocytes
Image Credit: Osaka Metropolitan University

Scientists obtained stem cells expressing cardiac muscle-specific genes and proteins. The cells displayed regular rhythmic contractions similar to a heart, confirming that they were functional cardiomyocyte cells.

In research, induced pluripotent stem (iPS) cells are derived from skin, urine, or blood samples and developed into other cells, like heart tissue, that researchers want to study. Because of the similarities between certain dog and human diseases, canine iPS cells have potential uses in regenerative medicine and drug discovery. 

New test can flag drugs that could be harmful to cats

Shelby
Photo Credit: Heidi-Ann Fourkiller

A new test developed at Washington State University will help pharmaceutical companies, veterinarians and regulatory agencies identify drugs that may trigger severe — but preventable — neurological side effects in some cats.

Even in healthy cats, many commonly prescribed drugs can cause dangerous reactions when administered in specific combinations or when given to felines born with a mutation in their MDR1 gene. This mutation disrupts a protein called P-glycoprotein, which normally helps remove harmful substances from the brain and body, putting affected cats at risk for serious reactions from drugs that are perfectly safe for most cats.

Developed by WSU veterinary pharmacologist Dr. Katrina Mealey and laboratory supervisor Neal Burke, the test can determine if a drug relies on P-glycoprotein to be safely processed. Using the test, Mealey and Burke identified 10 new drugs that pose a risk to affected cats. The findings were detailed in the journal Frontiers in Veterinary Science. The method is available as a fee-for-service through WSU, or companies and governing agencies can use the published procedure to run their own screenings.

Koala stress linked to disease threat

Many koalas in the study were successfully treated for Chlamydia before being released back into the wild.
Photo Credit: Currumbin Wildlife Hospital

Researchers have revealed a clear relationship between stress and increased disease risk in koalas in South East Queensland and on the New South Wales North Coast.

A study led by Dr Michaela Blyton at The University of Queensland measured and tracked the level of koala retrovirus (KoRV) in groups of captive and wild koalas.

“We wanted to see what happened to their KoRV loads over time and how it related to chlamydial infection and levels of the stress hormones cortisol and corticosterone in their feces,” Dr Blyton said.

“Virus load likely weakens the immune system, so those with a higher KoRV load are more at risk of diseases such as Chlamydia which can cause blindness, infertility and death.

“Poor quality or disappearing habitat may increase stress and the koalas with higher average cortisol levels had higher average KoRV loads.

Research Finds Dairy Farmers Receptive to Methane-Reducing Seaweed Feed

New research led by the University of New Hampshire examines the receptiveness of organic dairy farmers across Maine to pay an average of 64 cents more per cow per day to use methane-reducing seaweed-based feed to their cows, similar to those shown here.
Photo Credit: University of New Hampshire

New England’s dairy industry continues to evolve in response to significant market challenges that include a decreased demand for milk and higher production and land costs. However, there is also ongoing evidence that organic dairy farming can provide environmental benefits — such as reducing methane emissions — which could further differentiate their products as well as help qualify farms for new government initiatives to reduce methane through innovative management practices. Researchers from the University of New Hampshire collaborated with researchers in Maine to find evidence that nearly half of organic dairy farmers would be willing to pay a little extra for methane-reducing seaweed feed but would only consider if it was cost effective, aligned with existing feeding practices and would qualify them for government policies and subsidies.     

“Dairy farmers aim to run their farms as lucrative enterprises,” said Andre Brito, associate professor of dairy cattle nutrition and management and a scientist at UNH’s New Hampshire Agricultural Experiment Station. “The additional cost would require serious considerations, as well as more data and an effective implementation of carbon markets in the future.” 

Cats with MDR1 mutation at risk of severe reactions to popular medication

Photo Credit: Zhang Kaiyv

More than half a million cats in the United States could be at risk of a severe or even fatal neurological reaction to the active ingredient in some top-selling parasite preventatives for felines.

While the ingredient, eprinomectin, which is found in products like NexGard COMBO and Centragard, appears safe and effective for the significant majority of cats when used at label doses, a study conducted by Washington State University’s Program for Individualized Medicine identified a risk of severe adverse effects in cats with the MDR1 genetic mutation. Genetically affected cats lack a protective mechanism that prevents certain drugs, including eprinomectin, from entering the brain and causing serious neurological toxicity.

“Almost every week we receive reports about someone’s pet cat having serious reactions to eprinomectin. This is not an issue with the drug itself — the problem lies in the genes of 1% of cats. That is a sizable number considering there are over 60 million pet cats in the U.S., and we’re trying to increase general awareness of these risks,” said Dr. Katrina Mealey, a WSU veterinarian and pharmacologist who led the research.

The future of canine stem cell therapy: unprecedented, painless, and feeder-free

Generating canine induced pluripotent stem cells (iPSCs) without using feeder cells   Scientists created canine iPSCs from urine-derived cells with great efficiency     
Illustration Credit: Shingo Hatoya, Osaka Metropolitan University

Dog owners may need to learn to appreciate their best friend’s urine. Scientists at Osaka Metropolitan University have devised an efficient, non-invasive, and pain-free method to reprogram canine stem cells from urine samples, bringing furry companions one step closer to veterinary regenerative treatment.

Induced pluripotent stem cells (iPSCs) have been widely employed in studies on human generative medicine. With the growing importance of advanced medical care for dogs and cats, there is an expectation that new therapies utilizing iPSCs will be developed for these companion animals, just as they have been for humans. Unfortunately, canine somatic cells exhibit lower reprogramming efficiency compared to those of humans, limiting the types of canine cells available for generating iPSCs. IPSC induction often involves using feeder cells from a different species. However, considering the associated risks, minimizing xenogeneic components is often advisable, signifying the need to improve the efficiency of reprogramming various types of canine cells in dogs without using feeder cells.

Zika Infection in Pregnant Macaques Slows Fetal Growth

Female rhesus macaque monkeys and infants at the California National Primate Research Center at UC Davis.
Photo Credit: Courtesy of University of California, Davis

Zika virus infection in pregnant rhesus macaques slows fetal growth and affects how infants and mothers interact in the first month of life, according to a new study from researchers at the California National Primate Research Center at the University of California, Davis. The work, published Oct. 25 in Science Translational Medicine, has implications for both humans exposed to Zika virus and for other viruses that can cross the placenta, including SARS-CoV2, responsible for the COVID-19 pandemic.

“Initially I thought this was a story about Zika, but as I looked at the results, I think this is also a story about how fetal infections in general affect developmental trajectories,” said Eliza Bliss-Moreau, professor of psychology at UC Davis and senior author on the paper.

In most people, Zika virus infection causes mild or no symptoms and leaves long-lasting immunity. But during pregnancy, the virus can cross the placenta and cause damage to the nervous system of the fetus. In extreme cases, it can cause microcephaly in humans.

Scientists uncover cause of mysterious deaths of elephants in Zimbabwe

Photo Credit: Charl Durand

During this unique study, scientists from the Victoria Falls Wildlife Trust, the Animal and Plant Health Agency UK, the University of Surrey and laboratories in South Africa investigated the mysterious deaths of 35 elephants mostly between August and September 2020, in a 40 x 25 km radius of North-Western Zimbabwe. This incident followed the death of approximately 350 elephants in neighboring northern Botswana from May to June 2020, which triggered much international concern. 

African savanna elephants are an endangered species with only 350,000 remaining in the wild and ongoing losses estimated at eight percent annually. This finding is very worrying since elephants are on the International Union for Conservation of Nature red list already. Investigating the deaths of these elephants is crucial to sustaining the future of this majestic species. 

Identifying biosecurity to prevent CWD transmission

Photo Credit: Minnesota Board of Animal Health

As chronic wasting disease (CWD) ravaged deer populations across the country in recent years, studies have primarily focused on how CWD can jump from farmed herds to wild deer, with little attention given to how transmission may occur from wild deer to those living on farms. University of Minnesota researchers recently assessed the risks associated with the introduction of CWD to farmed deer herds in Minnesota, Pennsylvania and Wisconsin. Because CWD is highly infectious and sometimes fatal disease for deer with no treatment or vaccination available, strategies to prevent its spread are primary tools available to keep these animals healthy.

The study, published in Preventive Veterinary Medicine, examined various transmission pathways and their associated risk factors for farmed deer herds. The researchers collected data from 71 herds in three states, including both CWD-infected and disease-free herds. The data included deer movements, regulatory violations, CWD test results and distances to infected wild deer. They also interviewed deer farmers about their management practices.

Gut bacteria found in wild wolves may be key to improving domestic dogs’ health

Photo Credit: Nicky Pe

Gut microbes found in wild wolves may be the key to alleviating a debilitating gastrointestinal condition common to domestic dogs, according to a study led by researchers at Oregon State University – Cascades.

In a paper published in Applied Microbiology, the authors report a novel strain of Paenibacillus bacteria with characteristics of a probiotic – an organism that conveys a health benefit to the host.

In this case, the benefit would be to head off canine inflammatory bowel disease, a chronic illness characterized by vomiting, reduced appetite, weight loss, flatulence, a rumbling stomach and/or abdominal discomfort, said Bruce Seal of OSU-Cascades’ biology program.

“At present there is no known cure for this ongoing dysbiosis of the gastrointestinal tract, and there are limited options for treatment,” Seal said. “Underlying causes of the condition include an animal’s genetics, environmental factors, the immunological state of the GI tract and, maybe most importantly, an altered gut microbiome.”

Researchers Identify Genetic Makeup of New Strains of West Nile

This study shows the variety of strains in circulation and what mosquitoes may be carrying as we head into summer
Photo Credit: Jimmy Chan

Researchers at Connecticut Veterinary Medical Diagnostic Laboratory (CVMDL) located in UConn’s College of Agriculture, Health and Natural Resources identified the genetic makeup of strains of West Nile virus found in an alpaca and a crow.

These findings were published in Frontiers in Veterinary Science.

In 2021, eight cases of West Nile virus were brought to the CVMDL for diagnosis – seven birds, both domestic and wild – and one alpaca.

“We decided to pursue some research avenues through these diagnostic cases because we had an interesting cohort of West Nile cases that had come through that fall,” says Natalie Tocco ’23 (CAHNR), a resident in anatomic pathology the Department of Pathobiology and Veterinary Science.

Of the eight cases, the alpaca from Massachusetts and a crow from Connecticut had the highest amount of virus in their systems at the time of diagnosis.

Focusing on these two cases, the researchers were interested in seeing if there were genetic differences between the viruses because they occurred in different species in different states.

Gene-edited calf may reduce reliance on antimicrobials against cattle disease

 Brian Vander Ley, associate professor in the University of Nebraska–Lincoln’s School of Veterinary Medicine and Biomedical Sciences, works with Ginger, a Gir cow gene-edited with resistance to bovine viral diarrhea virus.
Photo Credit: Craig Chandler | University Communication and Marketing

Cattle worldwide face major health threats from a highly infectious viral disease that decades of vaccinations and other precautions have failed to contain. Federal, private-sector and Husker scientists are collaborating on a new line of defense, by producing a gene-edited calf resistant to the virus.

If follow-up research confirms its efficacy, the gene-editing approach offers long-term potential to reduce antimicrobial and antibiotic use in the cattle industry.

The bovine viral diarrhea virus devastates the bovine immune system and can cause severe respiratory and intestinal harm to infected beef and dairy cattle, said veterinary epidemiologist Brian Vander Ley, an associate professor in the University of Nebraska–Lincoln’s School of Veterinary Medicine and Biomedical Sciences.

In utero calves are especially vulnerable to infection. If they survive, they can remain infected for life, repeatedly spreading the virus to other cattle.

“They show up as normal cattle but really, they’re shedding a tremendous amount of virus. They’re the ‘Typhoid Marys’ of BVDV spread,” said Vander Ley, assistant director of UNL’s Great Plains Veterinary Educational Center in Clay Center.

Researchers map the genome of the world’s grumpiest cat

The mighty roar of a grumpy and angry Pallas' cat (Otocolobus manul)
Photo Credit: Johannes Heel

University of Minnesota researchers recently led successful efforts to build the first genome for Pallas’s cat (Otocolobus manul), a small wild cat native to central Asia known for its grumpy facial expression. The cat, which faces growing challenges from climate change, habitat fragmentation, and poaching, had no available genetic resources to help with conservation prior to this study. 

The study, published in NAR Genomics and Bioinformatics, was led by Nicole Flack, a doctoral candidate in the College of Veterinary Medicine, along with Christopher Faulk, a professor in the College of Food, Agricultural, and Natural Resource Sciences. 

The researchers used blood samples from Tater, a 6-year-old Pallas’s cat who lives at the Utica Zoo in New York, to construct a high-quality diploid nuclear genome assembly, a representative map of genes for the species.

The study results include confirmation that the Pallas’s cat is more closely related to certain wild cat species and less related to house cat species than some previous studies have suggested. 

Researchers Identify a New Genetic Culprit in Canine Bladder Cancers

Photo Credit: Lucie Helešicová

Researchers have identified new genetic mutations linked to a subset of canine bladder cancers. Their findings have implications both for early cancer detection and for targeted treatments in dogs and humans.

Previous research showed that 85% of canine urothelial carcinomas (a type of bladder cancer) share a specific mutation in a gene named BRAF. This mutation (known as V595E) is caused by an error in BRAF’s genetic code, where a normal ‘T’ nucleotide in the DNA sequence is substituted by an ‘A’. The BRAF V595E mutation results in abnormal activation of a genetic signaling pathway called MAPK, leading to uncontrolled cellular growth, or proliferation.

“Essentially, BRAF V595E generates an abnormal protein that instructs the cells to keep dividing, forming a tumor. So, if this single nucleotide substitution in the BRAF gene is detected in 85% of all canine urothelial carcinomas, why is it not in all of them?” asks Matthew Breen, Oscar J. Fletcher Distinguished Professor of Comparative Oncology Genetics at North Carolina State University and corresponding author of the research. “Pathologists see no difference between those cancers with this mutation and those without, so what’s going on with that other 15%?”

Lack of canine COVID-19 data fuels persisting concerns over dog-human interactions

A research literature review by Purdue University researchers published in the journal Animals highlights unanswered questions about the COVID-19 virus dynamics between dogs and humans.
 Photo Credit: Purdue Agricultural Communications photo/Tom Campbell

Early COVID-19 pandemic suspicions about dogs’ resistance to the disease have given way to a long-haul clinical data gap as new variants of the virus have emerged.

“It is not confirmed that the virus can be transmitted from one dog to another dog or from dogs to humans,” said veterinarian Mohamed Kamel, a postdoctoral fellow at Purdue University.

During the pandemic’s early days, dogs seemed resistant to the coronavirus, showing little evidence of infection or transmission, said Mohit Verma, assistant professor of agricultural and biological engineering and Purdue’s Weldon School of Biomedical Engineering. “As the virus evolved, or maybe the surveillance technology advanced, there seem to be more instances of potentially asymptomatic dogs.”

These are among the findings that Kamel, Verma and two co-authors summarized in a research literature review “Interactions Between Humans and Dogs in the COVID-19 Pandemic.” The summary, with recent updates and future perspectives, recently appeared in a special issue of the journal Animals on Susceptibility of Animals to SARS-CoV-2.