OREGON STATE UNIVERSITY

college of veterinary medicine

Use of dengue vaccine may cause short-term spikes in its prevalence

CORVALLIS, Ore. – As researchers continue to work toward vaccines for serious tropical diseases such as dengue fever, experts caution in a new report that such vaccines will probably cause temporary but significant spikes in the disease in the years after they are first used.

This counter-intuitive and unwanted result could lead to frustrated policy makers, a skeptical public and concerns that the vaccine is making things worse instead of better, researchers say.

In fact, it will just be the natural result of complex interactions between less-than-perfect vaccine protection and routine fluctuations in the populations of insects who carry the diseases.

“Our analysis suggests that if we develop and widely use a vaccine for dengue fever, there may later be spikes in the incidence of the disease that are two to three times higher than its normal level,” said Jan Medlock, an assistant professor in the Department of Biomedical Sciences at Oregon State University, and expert on the evolution and epidemiology of infectious disease.

“We can explain why this will happen and show how, in the long run, vaccine use will clearly result in fewer cases of disease,” Medlock said. “Our concern is to warn people in advance about this issue, so that policy makers and the public don’t freak out and lose faith in the vaccination programs.”

This research, published in Epidemiology and Infection, was done by experts at the OSU College of Veterinary Medicine and Clemson University, both of which supported the studies. Scientists used mathematical modeling to examine the quirks of infectious disease transmission that may lead to this quandary. The work was specific to dengue fever, but may also be relevant to other diseases for which vaccines are being sought, such as malaria, and in which the level of protection is less than total.

Dengue fever is a serious illness that affects about 50 million people a year, and for which researchers are hoping to develop effective vaccines in the near future. It’s not usually fatal but is extremely common in the tropics and subtropics, and has re-emerged in recent decades as the use of insecticides such as DDT has been stopped.

There are several serotypes, or strains of the dengue virus, that are spread by mosquitoes. One infection provides some protection, and two infections usually make a person resistant for the rest of their life. In Thailand, where the disease is prevalent, about 80 percent of children have two infections by the age of 11 and develop resistance. Dengue fever is found in 100 countries around the world and 2.5 billion people are at risk of infection.

“The problem, if and when we develop and use a vaccine, is that it will provide some, but not complete protection, and it will interrupt the natural, fairly steady rate of infections among children,” Medlock said.

In this scenario, the beginning of a vaccination program will slow the numbers of children getting the disease – for a while. But it’s expected that a dengue vaccine will not provide total protection against infection. Then, during a period when naturally fluctuating mosquito populations reach an unusually high level, a disproportionate number of children – who are still vulnerable to infection and have never had the disease – will become infected in a short period.

This could cause loss of faith in the vaccination program among the public or policy makers who have never seen such high levels of the disease, stretch the capabilities of health care facilities and workers to care for the sick, and in a worst-case scenario lead people to avoid the vaccine, researchers said. Some short-term spikes could even be as high as seven times the average rate, they said.

“In fact, we conclude in this analysis that over a 15-year period, a vaccination program will clearly reduce the number of overall infections,” Medlock said. “These significant spikes will mostly occur as the program is beginning. What we need to do is help people understand these forces so they anticipate them.”

A possible way to deal with this phenomenon, researchers said, is literally to vaccinate fewer people. This would cause higher numbers of people to get the disease in the long run but reduce the intensity of the spikes and the associated demands on a health care system.

The levels of disease will fluctuate based on such variables as location, climate, the efficacy of a vaccine, the numbers of people vaccinated, surges in insect populations, and other factors. This phenomenon may have occurred, or may occur in the future, with almost any vaccine that provides partial, but not total protection against infection.

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Dengue mosquito

Dengue transmission

Research could lead to new cancer assay, aid both dogs and humans

CORVALLIS, Ore. – Veterinary researchers at Oregon State University have identified a unique group of proteins that indicate the presence of transitional cell carcinoma – the most common cause of bladder cancer – and may lead to a new assay which could better diagnose this disease in both dogs and humans.

Bladder cancer is particularly common in some dog breeds, such as collies, sheepdogs and terriers, but is rarely diagnosed in animals before it has spread significantly. Some assays exist to detect it in humans, but they often have a high-number of false-positive identifications.

An improved assay to detect this serious disease much earlier in both animals and humans should be possible, scientists said, and may even become affordable enough that it could be used as an over-the-counter product to test urine, much like a human pregnancy test. Some of the work may also contribute to new therapies, they said.

“Research of this type should first help us develop a reliable assay for this cancer in dogs, and improve the chance the disease can be caught early enough that treatments are effective,” said Shay Bracha, an assistant professor in the OSU College of Veterinary Medicine.

“However, this type of cancer is essentially the same in dogs and humans,” Bracha said. “Dogs are an excellent model for human cancer research, and an assay that works with dogs should be directly relevant to creation of a similar assay for humans. We hope to make it inexpensive and convenient, something that people could use routinely to protect either the health of their pets or themselves.”

The findings were published recently in Analytical Chemistry, a professional journal.

In this research, scientists used mass spectrometry and the evolving science of proteomics to identify 96 proteins that appear related to transitional cell carcinoma. This is a fairly common cancer in dogs, often as a result of exposure to pesticides, herbicides, and poor quality foods; and in humans is closely related to smoking.

Advanced-stage disease in both dogs and humans has a poor prognosis, as chemotherapy and radiation treatments are often ineffective. Average survival time is less than one year. Some assays exist to help identify the disease in humans but can produce false positive results, often as a result of urinary tract infections. And the biopsies used to make a definitive diagnosis require general anesthesia and also run the risk of actually spreading the disease.

The group of proteins identified in this research already have a 90 percent accuracy, and researchers say they hope to improve upon that with continued research.

However, researchers say that some of these proteins are more than just biomarkers of the disease – they are part of the disease process. Identifying proteins that are integral to the spread of the cancer may allow new targets for intervention and cancer therapies, they said.

Collaborators on this research included the OSU Department of Chemistry. A mathematical model that was integral to the study was created by Jan Medlock, an OSU assistant professor of veterinary medicine, and veterinary researchers Michael McNamara and Ian Hilgart helped initiate the project. The work was supported in part by the National Institutes of Health.

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Shay Bracha, 541-737-4844

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Border collie

Border collie

OSU assisting in alpaca rescue operation

CORVALLIS, Ore. - The last of about 175 imperiled alpacas that are being removed from a farm near Falls City, Ore., will arrive today or early this week at Oregon State University as part of a continuing rescue operation to help care for and save the lives of these animals.

Transport began late last week but only 54 got through, and operations had to be suspended due to the heavy winter storm, a traffic accident and difficult travel conditions. A team of doctors and veterinary students at OSU will now work with the incoming animals to assess their health, do necessary procedures, improve their nutritional status and aid their recovery.

Owners of the ranch that had housed the alpacas are facing legal charges in Polk County. Meanwhile, the College of Veterinary Medicine has volunteered its facilities to help continue the rescue operation that was begun by the Polk County Sheriff’s Department and Cross Creek Alpaca Rescue volunteers.

Ultimately, all of the animals will be made available for adoption, officials said.

“The OSU College of Veterinary Medicine is one of the few agencies in Oregon that has the ability and expertise to manage an operation of this size,” said Helen Diggs, a professor of veterinary medicine and director of the OSU Laboratory Animal Resources Center. “The Research Office at OSU has also made it clear that we will do what we can to help with this difficult situation.”

Although travel is still difficult, officials hope that most of the remaining alpacas will arrive today or early this week at the Research Animal Isolation Laboratory, one of the campus facilities large enough to handle so many animals at once. Some with special needs are also being treated in the large animal hospital in Magruder Hall on the OSU campus.

“Many of these animals are very thin and we’ve been told that a substantial number have already died,” said Chris Cebra, a professor of large animal internal medicine in the College of Veterinary Medicine, and an expert in the treatment of camelids such as llamas and alpacas.

“From what we’ve seen, we’ll be dealing with malnutrition, heavy parasite loads, some pregnant animals, newborns, and various health conditions,” Cebra said. “We’ll continue to feed the animals, assess and treat medical conditions, check vaccination status, and generally improve their quality of life and suitability for a new home.”

Given the unusually large influx of animals at one time, a number of supervised veterinary students will also work in the rescue operation, allowing them a substantial amount of hands-on training while helping veterinary doctors more quickly and effectively give the entire herd the treatment it needs.

Once the alpacas recover their health, adoption will be possible from the Polk County Sheriff’s Office, which is working with Cross Creek Alpaca Rescue to identify suitable placements. Initial inquiries for adopting one or more of the animals may be directed to Cross Creek Alpaca Rescue, at http://www.crosscreekalpacarescue.org/.

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Helen Diggs, 541-737-6213

 

Chris Cebra, 541-737-4456

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Alpaca needs care


Alpacas being fed

Alpacas being fed

Amber fossil reveals ancient reproduction in flowering plants

CORVALLIS, Ore. – A 100-million-year old piece of amber has been discovered which reveals the oldest evidence of sexual reproduction in a flowering plant – a cluster of 18 tiny flowers from the Cretaceous Period – with one of them in the process of making some new seeds for the next generation.

The perfectly-preserved scene, in a plant now extinct, is part of a portrait created in the mid-Cretaceous when flowering plants were changing the face of the Earth forever, adding beauty, biodiversity and food. It appears identical to the reproduction process that “angiosperms,” or flowering plants still use today.

Researchers from Oregon State University and Germany published their findings on the fossils in the Journal of the Botanical Institute of Texas.

The flowers themselves are in remarkable condition, as are many such plants and insects preserved for all time in amber. The flowing tree sap covered the specimens and then began the long process of turning into a fossilized, semi-precious gem. The flower cluster is one of the most complete ever found in amber and appeared at a time when many of the flowering plants were still quite small.

Even more remarkable is the microscopic image of pollen tubes growing out of two grains of pollen and penetrating the flower’s stigma, the receptive part of the female reproductive system. This sets the stage for fertilization of the egg and would begin the process of seed formation – had the reproductive act been completed.

“In Cretaceous flowers we’ve never before seen a fossil that shows the pollen tube actually entering the stigma,” said George Poinar, Jr., a professor emeritus in the Department of Integrative Biology at the OSU College of Science. “This is the beauty of amber fossils. They are preserved so rapidly after entering the resin that structures such as pollen grains and tubes can be detected with a microscope.”

The pollen of these flowers appeared to be sticky, Poinar said, suggesting it was carried by a pollinating insect, and adding further insights into the biodiversity and biology of life in this distant era. At that time much of the plant life was composed of conifers, ferns, mosses, and cycads.  During the Cretaceous, new lineages of mammals and birds were beginning to appear, along with the flowering plants. But dinosaurs still dominated the Earth.

“The evolution of flowering plants caused an enormous change in the biodiversity of life on Earth, especially in the tropics and subtropics,” Poinar said.

“New associations between these small flowering plants and various types of insects and other animal life resulted in the successful distribution and evolution of these plants through most of the world today,” he said. “It’s interesting that the mechanisms for reproduction that are still with us today had already been established some 100 million years ago.”

The fossils were discovered from amber mines in the Hukawng Valley of Myanmar, previously known as Burma. The newly-described genus and species of flower was named Micropetasos burmensis.

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George Poinar, 541-752-0917

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Ancient flowers

Ancient flower


Pollen tubes

Pollen tubes

Innovative approach could ultimately end deadly disease of sleeping sickness

CORVALLIS, Ore. – A tag team of two bacteria, one of them genetically modified, has a good chance to reduce or even eliminate the deadly disease African trypanosomiasis, or sleeping sickness, researchers at Oregon State University conclude in a recent mathematical modeling study.

African trypanosomiasis, caused by a parasite carried by the tsetse fly, infects 30,000 people in sub-Saharan Africa each year and is almost always fatal without treatment. In a 2008 epidemic, 48,000 people died.

In this research, scientists evaluated the potential for success of a new approach to combat the disease – creating a genetically modified version of the Sodalis bacteria commonly found in the gut of the flies that carry the disease, and using different bacteria called Wolbachia to drive the GMO version of Sodalis into fly populations.

When that’s done, the GMO version of Sodalis would kill the disease-causing trypanosome parasite. According to the analysis published in PLOS Neglected Tropical Diseases, researchers say this should work – and could offer a model system for other tropical, insect-carried diseases of even greater importance, including dengue fever and malaria.

“There are a few ‘ifs’ necessary for this to succeed, but none of them look like an obstacle that could not be overcome,” said Jan Medlock, an assistant professor in the OSU Department of Biomedical Sciences, and lead author on the new report.

“If everything goes right, and we are optimistic that it will, this could be enormously important,” Medlock said. “There’s a potential here to completely solve this disease that has killed many thousands of people, and open new approaches to dealing with even more serious diseases such as malaria.”

Some of the “ifs” include: the transgenic Sodalis has to be reasonably effective at blocking the parasite, at or above a level of about 85 percent; the Wolbachia bacteria, which has some effect on the health of flies affected with it, must not kill too many of them; and the target species of fly has to be a majority of the tsetse flies in the areas being treated.

The research shows that dealing with all of those obstacles should be possible. If so, this might spell the end of a tropical disease that has plagued humans for hundreds, possibly thousands of years. African trypanosomiasis causes serious mental and physical deterioration – including the altered sleep patterns that give the disease its name – and is fatal without treatment. It’s still difficult to treat, and neurologic damage is permanent.

Past efforts to control the disease, including insect traps, insecticide spraying, and use of sterile insects have been of some value, but only in limited areas and the effects were not permanent.

The strength of the new approach, researchers say, is that once the process begins it should spread and be self-sustaining - it should not be necessary to repeatedly take action in the huge geographic areas of Africa. Due to some genetic manipulation, the flies carrying the Wolbachia bacteria should naturally increase their populations and have an inherent survival advantage over conventional tsetse flies.

As the flies carrying transgenic bacteria continue to dominate and their populations spread, trypanosomiasis should fairly rapidly disappear. Whether the mechanism of control could wane in effectiveness over time is an issue that requires further study, scientists said.

Work has begun on the GMO version of Sodalis that has the capability to resist trypanosomes . It’s not yet finalized, Medlock said, but it should be possible, and when complete, the bacteria will be very specific to tsetse flies.

Medlock, an expert in modeling the transmission of various diseases – including human influenza – says the analysis is clear that this approach has significant promise of success. Because of the relatively low infectiousness of the parasite and the ability of Wolbachia to drive the resistance genes, no part of the system has to be 100 percent perfect in order to ultimately achieve near eradication of this disease, he said.

Accomplishing a similar goal with diseases such as malaria may be more difficult, he said, because that disease historically has shown a remarkable ability to mutate and overcome many of the approaches used to attack it. However, at least some near-term gains may be possible, he said.

Collaborators on this study included scientists from the OSU College of Veterinary Medicine and the Yale School of Public Health. It was supported by the National Institutes of Health and the Miriam Weston Trust.

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Jan Medlock, 541-737-6874

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Tsetse fly

Tsetse fly

Gut microbes closely linked to range of health issues

CORVALLIS, Ore. –A new understanding of the essential role of gut microbes in the immune system may hold the key to dealing with some of the more significant health problems facing people in the world today, Oregon State University researchers say in a new analysis.

Problems ranging from autoimmune disease to clinical depression and simple obesity may in fact be linked to immune dysfunction that begins with a “failure to communicate” in the human gut, the scientists say. Health care of the future may include personalized diagnosis of an individual’s “microbiome” to determine what prebiotics or probiotics are needed to provide balance.

Appropriate sanitation such as clean water and sewers are good. But some erroneous lessons in health care may need to be unlearned – leaving behind the fear of dirt, the love of antimicrobial cleansers, and the outdated notion that an antibiotic is always a good idea. We live in a world of “germs” and many of them are good for us.

“Asked about their immune system, most people might think of white blood cells, lymph glands or vaccines,” said Dr. Natalia Shulzhenko, author of a new report in Clinical Reviews in Allergy and Immunology, and assistant professor and physician in the OSU Department of Biomedical Sciences. “They would be surprised that’s not where most of the action is. Our intestines contain more immune cells than the entire rest of our body.

“The human gut plays a huge role in immune function,” Shulzhenko said. “This is little appreciated by people who think its only role is digestion. The combined number of genes in the microbiota genome is 150 times larger than the person in which they reside. They do help us digest food, but they do a lot more than that.”

An emerging theory of disease, Shulzhenko said, is a disruption in the “crosstalk” between the microbes in the human gut and other cells involved in the immune system and metabolic processes.

“In a healthy person, these microbes in the gut stimulate the immune system as needed, and it in turn talks back,” Shulzhenko said. “There’s an increasing disruption of these microbes from modern lifestyle, diet, overuse of antibiotics and other issues. With that disruption, the conversation is breaking down.”

An explosion of research in the field of genomic sequencing is for the first time allowing researchers to understand some of this conversation and appreciate its significance, Shulzhenko said. The results are surprising, with links that lead to a range of diseases, including celiac disease and inflammatory bowel disease. Obesity may be related. And some studies have found relevance to depression, late-onset autism, allergies, asthma and cancer.

In the new review, researchers analyzed how microbe dysfunction can sometimes result in malabsorption and diarrhea, which affects tens of millions of children worldwide and is often not cured merely by better nutrition. In contrast, a high-fat diet may cause the gut microbes to quickly adapt to and prefer these foods, leading to increased lipid absorption and weight gain.

The chronic inflammation linked to most of the diseases that kill people in the developed world today – heart disease, cancer, diabetes – may begin with dysfunctional gut microbiota.

Understanding these processes is a first step to addressing them, Shulzhenko said. Once researchers have a better idea of what constitutes healthy microbiota in the gut, they may be able to personalize therapies to restore that balance. It should also be possible to identify and use new types of probiotics to mitigate the impact of antibiotics, when such drugs are necessary and must be used.

Such approaches are “an exciting target for therapeutic interventions” to treat health problems in the future, the researchers concluded.

The study, supported by OSU, included researchers from both the College of Veterinary Medicine and the College of Pharmacy.

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Dr. Natalia Shulzhenko, 541-737-1051

McDonald Forest open, not found to pose any special risk to pets

CORVALLIS, Ore. – After further evaluation, officials at Oregon State University say there is no apparent geographic connection that would link dogs that had recently become ill with visitation to the McDonald Forest area north of Corvallis, and the area remains open for public use as usual.

Veterinarians and researchers from the OSU College of Veterinary Medicine, Veterinary Diagnostic Laboratory, College of Forestry and Research Forests have examined these cases, following public reports that one or more dogs may have become ill after drinking from water in the area.

Upon closer examination of all cases, including communication with pet owners, they found no geographic link between the cases, no consistent symptoms of ill health and no way to attribute illnesses to any known toxin.

“After reviewing these cases, we could find no evidence that suggests something in McDonald Forest is posing a special risk to animals,” said Jana Gordon, an assistant professor in the OSU College of Veterinary Medicine and expert in small animal internal medicine. “In light of that, the forest will remain open for public use and pets will continue to be welcome there.”

OSU officials said that pet owners should continue to take ordinary precautions as they would anytime they bring pets into a forest or wildlife area. Pets are at risk of injury from falls, encounters with wildlife, or consuming unclean water, plants, animals and animal matter that may cause illness. Pets that aren’t physically fit or have some medical conditions may also be more susceptible to exercise or heat-induced illness.

Routine precautions when visiting a forested or wild land area should include:

  • Pets should be kept on a leash and under supervision at all times;
  • Encounters between pets and other wildlife should be avoided;
  • Water should be carried in for the pets, or water purification systems used;
  • A veterinarian should be consulted if a pet has any medical conditions, exercise restrictions or other precautions;
  • A pet should be kept well-hydrated and cool when exercising in warm weather.

If a pet shows any signs of illness following outdoor activities, a veterinarian should be contacted immediately.

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Jana Gordon, 541-737-4808

OSU treats horse with Equine Herpes Virus (EHV-1)

CORVALLIS, Ore. – Oregon State University this week has diagnosed a horse with the neurologic form of Equine Herpes Virus 1 (EHV-1), a naturally occurring virus that can cause serious illness in horses when activated.

The horse is isolated at the Lois Bates Acheson Veterinary Teaching Hospital, and all activities and services in the College of Veterinary Medicine are continuing.

The Oregon Department of Agriculture has quarantined the property where the affected horse was housed in Marion County.

No other horses that attended these events have shown clinical signs of EHV-1. Owners of horses that attended these events are encouraged to monitor their horses for any signs of respiratory or neurologic disease. EHV-1 is not transmissible to people.

“This is not the neurotropic or mutated form of the virus, which can really cause problems,” said John Schlipf, a large animal internal medicine specialist with the OSU College of Veterinary Medicine. “This form of EHV-1 can still have serious consequences.”

Schlipf said that clinical signs of the neurologic form of EHV-1 often begin with the hind limbs and include:

  • Uncoordinated, stumbling movements;
  • An unusual gait;
  • A weak tail tone;
  • Difficulty urinating, and dribbling of urine;
  • Nasal discharge, frequently accompanied by a fever.

The Oregon Department of Agriculture recommends horses that attended the Albany or Eugene events avoid contact with other horses and have their temperatures monitored twice daily. Temperatures over 101.5 degrees may indicate illness.

Horses with signs listed above should be isolated from other animals, and owners should contact their veterinarians immediately. EHV-1 can also affect alpacas and llamas, Schlipf said.

EHV-1 can cause abortions in animals, thus pregnant mares should not co-mingle with horses returning from those shows.

“Horse owners should be aware that although EHV-1 is not transmissible to humans, people can spread the virus on their hands and clothing if in contact with an infected horse,” Schlipf said.

Additional information regarding Equine Herpes Virus and biosecurity recommendations is available from the American Association of Equine Practitioners: http://www.aaep.org/info/horse-health?publication=753.

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 John Schlipf, 541-737-6962;  john.schlipf@oregonstate.edu

OSU names Susan Tornquist dean of veterinary medicine

CORVALLIS, Ore. – Susan Tornquist, who has been interim dean of the College of Veterinary Medicine  at Oregon State University since October of 2013, has been named dean of the college.

Tornquist has been on the faculty at Oregon State since 1996 and previously was associate dean of student and academic affairs in the college, where she also is a professor of clinical pathology.

“Sue Tornquist has been a very effective leader for the College of Veterinary Medicine over the past 17 months, and has demonstrated that she has the very best interests of the college at heart and the skill set for enhancing the college’s education, clinical services, research and outreach,” said Sabah Randhawa, OSU’s provost and executive vice president.

While Tornquist was interim dean, the college surpassed its fund-raising goal of $47 million through The Campaign for OSU; again received full accreditation in 2014 from the American Veterinary Medicine Association; launched a new graduate program in comparative health sciences; and saw the class of 2014 achieve a 100 percent pass rate for the national board exam for veterinarians.

Tornquist said the OSU College of Veterinary Medicine has a bright future.

“We are looking forward to great opportunities for research and strengthened clinical capabilities in oncology and infectious diseases and continued collaboration with Oregon Humane Society in providing experiential learning opportunities for veterinary students while providing needed veterinary services for animals in need,” Tornquist said.

“There are also new opportunities and initiatives in One Health for undergraduate students,” she added. “We hope to see expansion in both instructional and clinical facilities in the next five years.”

As associate dean, Tornquist helped the college grow its enrollment, coordinate student internships, build partnerships with the Oregon Humane Society and other organizations, and make student experiential learning a hallmark of the program.

Tornquist received her veterinary medical degree from Colorado State University and her doctorate in veterinary pathology from Washington State University. Her research interests have focused on immune responses to infectious and metabolic diseases in animals, particularly llama and alpacas.

Before coming to Oregon State, she was on the veterinary medicine faculty at Washington State University from 1990-96. She also has been a research associate in New Mexico’s Veterinary Diagnostic Services office; an associate veterinarian in private practice in New Mexico; and a teaching and research assistant at the University of New Mexico.

Tornquist succeeds Cyril Clarke as dean, who resigned in 2013 to become dean of the Virginia-Maryland Regional College of Veterinary Medicine.

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Sabah Randhawa, 541-737-2111, Sabah.randhawa@oregonstate.edu

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Susan Tornquist

Veterinary hospital resuming normal operation after cases of equine influenza

CORVALLIS, Ore. – The Lois Bates Acheson Veterinary Teaching Hospital at Oregon State University will resume normal operations on Thursday, Dec. 4, following several cases of equine influenza that for the past week had kept it from accepting horses for anything but emergency services.

There are three remaining horses that still have the infection but are being housed in an isolation unit. They pose no risk to the general hospital operation, officials say, where no horses are now testing positive for the virus.

Equine influenza is a highly contagious respiratory disease in horses that usually isn’t fatal, but is a particular concern to foals and pregnant horses, since it can cause abortion. The original source of the infection appears to be a horse admitted to the hospital.

All horse stalls in the Large Animal Hospital have been disinfected and left empty for an adequate time to kill any remaining flu virus in a dry environment.

“We’d like to thank all of our clients for their patience and cooperation,” said Ron Mandsager, interim associate director of the hospital. “Equine influenza is endemic in the U.S. and sometimes these situations occur, and we had to take the necessary precautions to protect the health of our animals.”

Equine influenza is not transferable to humans or other animal species, but can spread rapidly among horses and other equines. It is the most common contagious respiratory pathogen for horses and most animals fully recover. However, young, elderly or pregnant animals are more at-risk for viral diseases such as equine influenza.

Incidents such as this, hospital officials said, should remind all horse owners to vaccinate their animals, practice good biosecurity, and monitor horses closely when they are in contact with other horses during and after events like fairs, competitions and trail rides.

The first clinical sign of this disease in horses is typically a fever, followed by cough, nasal discharge and lethargy. Horses with a fever of greater than 102.5 degrees should be seen by a veterinarian.

Anyone who has concerns about the health of their animals should contact their veterinarian or the Lois Bates Acheson Veterinary Teaching Hospital at OSU, at 541-737-2858 or http://vetmed.oregonstate.edu/

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Ron E. Mandsager, 541-737-6440