Gold nanoparticle prostate cancer treatment found safe in dogs, study shows

Oct. 15, 2012 — Currently, large doses of chemotherapy are required when treating certain forms of cancer, resulting in toxic side effects. The chemicals enter the body and work to destroy or shrink the tumor, but also harm vital organs and drastically affect bodily functions. Now, scientists at the University of Missouri have demonstrated that a new form of prostate cancer treatment that uses radioactive gold nanoparticles, and was developed at MU, is safe to use in dogs. Sandra Axiak-Bechtel, an assistant professor in oncology at the MU College of Veterinary Medicine, says that this is a big step for gold nanoparticle research.

"Proving that gold nanoparticles are safe to use in the treatment of prostate cancer in dogs is a big step toward gaining approval for clinical trials in men," Axiak-Bechtel said. "Dogs develop prostate cancer naturally in a very similar way as humans, so the gold nanoparticle treatment has a great chance to translate well to human patients."

For their treatment, Kattesh Katti, a curators' professor of radiology and physics in the School of Medicine and the College of Arts and Science, and other MU scientists, have found a more efficient way of targeting prostate tumors by using radioactive gold nanoparticles. This new treatment would require doses that are thousands of times smaller than chemotherapy and do not travel through the body inflicting damage to healthy areas.

"We found remarkable results in mice, which showed a significant reduction in tumor volume through single injections of the radioactive gold nanoparticles," said Katti. "These findings have formed a solid foundation, and we hope to translate the utility of this novel nanomedicine therapy to treating human cancer patients."

Current treatments for prostate cancer are not effective in patients who have aggressive prostate cancer tumors. Most of the time, prostate cancers are slow-growing; the disease remains localized and it is easily managed. However, aggressive forms of the disease spread to other parts of the body, and is the second-leading cause of cancer deaths in U.S. men. The MU scientists believe their treatment will be able to shrink aggressive tumors or eliminate them completely. Axiak-Bechtel says this treatment can be safe and effective in dogs as well as humans because dogs are the only other mammal to naturally contract the aggressive form of prostate cancer.

"Being able to test the gold nanoparticle treatment on dogs is very helpful, because dogs develop these tumors naturally," Axiak-Bechtel said. "Because dogs can't tell us how they feel, many times they are diagnosed with the disease too late, but this treatment gives us some hope that we can still combat aggressive tumors."

Axiak-Bechtel and Katti, who is also a senior research scientist at the MU Research Reactor, have been working with colleagues in the Department of Radiology and Cathy Cutler at the MU Research Reactor, to develop the gold nanoparticle treatment. This research was presented at the 2012 World Veterinary Cancer Conference in Paris.

This study is a result of collaboration through the One Health, One Medicine area of Mizzou Advantage. Mizzou Advantage is a program that focuses on four areas of strength: food for the future, media of the future, one health, one medicine, and sustainable energy. The goals of Mizzou Advantage are to strengthen existing faculty networks, create new networks and propel Mizzou's research, instruction and other activities to the next level.

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A healthy bond: By improving pain treatment, therapy in dogs, research offers medical insight for humans

Sep. 25, 2012 — A Kansas State University professor's research improving post-surgery pain treatment and osteoarthritis therapy in dogs may help develop better ways to treat humans for various medical conditions.

From the use of hot and cold packs to new forms of narcotics, James Roush, professor of clinical sciences, is studying ways to lessen pain after surgery and improve care for small animals, particularly dogs. He is working with the clinical patients who come to the College of Veterinary Medicine's Veterinary Health Center.

Because humans and dogs experience some diseases in similar ways, his research may improve how doctors and physicians understand human health, too.

"Several of our projects have human applications, particularly one involving intra-articular prolotherapy," Roush said.

Here's a closer look at three of Roush's current projects:

* A recent project with Ralph Millard, former Veterinary Health Center resident, focuses on ways that hot packing and cold packing affect tissue temperature in beagles and beagle-sized dogs after surgery.

After surgery in both humans and dogs it is common to put a cold pack or hot pack on tissue to prevent and reduce swelling. How long the pack is used and what type of cold or hot pack is used depends on the type of injury and surgery. Roush said that no studies have looked at how deep in the tissue the packs affect temperature and how long the packs must be applied so that the tissue reaches a desired temperature.

The researchers studied the temperature and tissue depth that hot and cold packing affected and the time it took to reach that temperature.

"We found that you don't really need to cold pack anything longer than 10 minutes because there is not a great change in temperature after that," Roush said.

When tissue is cold packed, it will stay cold for a while after the ice pack is removed. But when tissue is hot packed and the pack is removed, the tissue temperature will return to normal much more quickly. Leaving the hot or cold pack on the tissue longer than 10 minutes will extend the time that the tissue stays at the same hot or cold temperature, Roush said. There just will not be a great change in temperature after 10 minutes.

The same technique of hot and cold packing after surgery is also used in humans. Although more research in humans is needed, Roush said there is a strong possibility that a similar 10-minute time frame for hot and cold packing may apply to humans as well.

The research appears in two upcoming publications in the Journal of Veterinary Research.

* For another project, Roush and Matt Sherwood, Veterinary Health Center resident, are using a mat system to study lameness and osteoarthritis in dogs. When dogs step on the mat, it measures the pressure in their step.

The mat system is a useful clinical tool for evaluating and developing treatment of lameness, Roush said. Roush and Sherwood are using the mat for measuring lameness and determining in which leg the lameness is worse.

"We've designed the study to help improve osteoarthritis treatment," Roush said. "We will also use it to measure clinical patients when they come in for regular checkups. We can measure their recovery and a variety of other aspects: how they respond to nonsteroidal anti-inflammatories, how they respond to narcotics or how they respond to a surgical procedure that is designed to take that pressure off the joint."

* Roush also is working with Marian Benitez, Veterinary Health Center resident, on an analgesic pharmacology study. Rose McMurphy, professor of clinical sciences, and Butch KuKanich, associate professor of anatomy and physiology, are also involved.

The researchers are studying the effectiveness of a painkiller used to treat dogs and researching potential alternatives to the drug. The same drug also is commonly used to treat pain in humans.

"To achieve the drug's effect, the dosage in dogs is much higher than in people," Roush said. "It also may not be a very good analgesic in dogs. We want to see if there is an alternative that requires smaller doses and does not have not as much of a discrepancy for patients."

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Taking the battle against the toxic trio beyond 'Leaves of three, leave it be'

Sep. 26, 2012 — With more than half of all adults allergic to poison ivy, oak and sumac, scientists are reporting an advance toward an inexpensive spray that could reveal the presence of the rash-causing toxic oil on the skin, clothing, garden tools, and even the family cat or dog. Using the spray, described in ACS' The Journal of Organic Chemistry would enable people to wash off the oil, or avoid further contact, in time to sidestep days of misery.

Rebecca Braslau and colleagues explain that allergic reactions to oils of the toxic trio are more than a nusiance. They claim a huge human and economic toll, accounting for thousands of medical visits, days lost from work and school and sheer misery for the victims. It takes only 0.04th of a drop of the plants' oil to trigger a reaction, and the oil is invisible. The scientists thus sought to begin developing a way to make the oil visible, so that people can do a reality check after venturing into outdoor areas where the toxic plants grow.

They describe development of a spray that, when applied to leaves of poison ivy, oak and sumac, reacts with urushiol, the toxic oil produced by those plants. When exposed to an ordinary fluorescent light, the spray glows if urushiol is present, revealing the location of the oil. "This constitutes the groundwork for the future development of a spray to detect urushiol to avoid contact dermatitis," the scientists say.

The authors acknowledge funding from the University of California Santa Cruz Committee on Research.

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Rebecca Braslau, Frank Rivera, Erin Lilie, MariEllen Cottman. Urushiol Detection using a Profluorescent Nitroxide. The Journal of Organic Chemistry, 2012; 120829150558000 DOI: 10.1021/jo301135m

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Healthy mom with lots of help key to thriving brood, wolf study shows

Oct. 9, 2012 — What does it take to raise successful, self-sufficient offspring? A healthy mom with lots of in-house help, says Utah State University researcher Dan MacNulty. While this advice may benefit humans, a recent study by MacNulty and colleagues actually focuses on another group of large, social mammals -- namely, wolves.

"Using 14 years of data from the long-term study of wolves in Yellowstone National Park, we examined a number of key traits that allow wolves to overcome environmental stress," says MacNulty, assistant professor in USU's Quinney College of Natural Resources. "We discovered mother wolves' body weight and pack size play a crucial role in enabling pups to survive and thrive from birth to young adulthood."

With Dan Stahler and Doug Smith of the National Park Service's Yellowstone Wolf Project, as well as Robert Wayne and Bridgett vonHoldt of the University of California, Los Angeles, MacNulty published findings in the Oct. 9, 2012, online edition of the Journal of Animal Ecology. The study, which stems from a newly established collaboration between the wolf project and USU, was funded by the National Science Foundation, National Park Service and the Yellowstone Park Foundation, along with private donors.

Environmental conditions that impact wolf reproduction, the researchers say, include disease prevalence, especially deadly canine distemper -- caused by a contagious virus to which pups are especially vulnerable; resource availability and population density. In addition to body weight and pack size, the researchers examined effects of maternal age, color (gray or black coat) and wolf population size on reproductive success.

"Each of these factors affects reproduction but, overwhelmingly, female body weight and pack size are the main drivers of litter size and pup survival," says Stahler, the study's lead author. "Bigger females produce bigger litters; bigger packs are better equipped to hunt and defend pups and resources from competitors."

Social carnivores, wolves live in territorial, kin-structured packs. Female wolves depend on other adults in the pack to help them provide food for their pups and defend the youngsters from predators; mainly, competing packs of wolves.

"Motherhood is a challenge for any species," Stahler says, "But the evolution of cooperation in wolf societies is a notable benefit to mother wolves."

As wolf management in the United States moves from recovery to a new era of conservation, the researchers believe knowledge of reproduction will help managers maintain wolf populations. With the recent de-listing of gray wolves in Wyoming, state managers assume control of the last federally protected group of these animals in the Northern Rockies this fall.

"While these animals are no longer protected under the Endangered Species Act, states are required to maintain a minimum number of wolves and breeding pairs to prevent re-listing," MacNulty says. "As in Idaho and Montana, Wyoming is legally required to maintain a statewide population of at least 100 wolves, including 10 breeding pairs."

A breeding pair, he says, is defined as an adult male and female with at least two pups surviving to the end of the calendar year.

He adds the Yellowstone study highlights factors that determine the number of pups surviving to the end of the year, and this information may help state managers meet population objectives.

"Managers could use information on pack size, weight of harvested female wolves, or disease prevalence as indicators of future population growth and set harvest limits accordingly," MacNulty says.

If pack sizes are small, female wolves are underweight or disease outbreaks occur, he says, managers could reduce harvest to ensure sufficient numbers of breeding pairs. On the other hand, if pack sizes are relatively large, female wolves are at healthy weights and acute diseases are absent, managers can have confidence that current harvest levels are appropriate.

"Biologists and managers have long recognized the resiliency of wolves," Stahler says. "Our findings point to traits that help explain wolves' ability to overcome environmental challenges like human exploitation or competition with other wolves."

While these findings are specific to the unexploited Yellowstone National Park population, they may well represent important biological drivers of reproduction in any wolf population, he says.

"Long-term, detailed studies from wild ecosystems like Yellowstone's enhance our knowledge about these charismatic, but controversial carnivores," Stahler says. "This type of research has great value in informing anyone who has an opinion about wolves."

"Our results should reassure wolf conservationists," MacNulty says. "If female body weights are high and pack sizes are sufficiently large, wolves can successfully reproduce despite the impact of environmental factors, such as disease and competition."

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Daniel R. Stahler, Daniel R. MacNulty, Robert K. Wayne, Bridgett vonHoldt, Douglas W. Smith. The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves. Journal of Animal Ecology, 2012; DOI: 10.1111/j.1365-2656.2012.02039.x

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Yellowstone wolf study reveals how to raise successful offspring

Oct. 10, 2012 — What are the key ingredients to raising successful, self-sufficient offspring? A new life sciences study using 14 years of data on gray wolves in Yellowstone National Park indicates that cooperative group behavior and a mother's weight are crucial.

"A female's body weight is key in the survival of her offspring, and cooperation in the protection and feeding of young pups pays off in terms of the production of offspring," said Robert Wayne, a professor of ecology and evolutionary biology at UCLA and co-author of the new research, published this week in the online edition of the Journal of Animal Ecology.

Wolves are social carnivores that live in territorial, kin-structured packs. Female wolves depend on other adults in the pack to help them provide food for their pups and defend the youngsters from predators -- mainly, competing packs of wolves. The greater the group cooperation, the researchers say, the better the pack's survival advantage.

"Consequently, larger packs tend to get larger and win the 'arms race' of holding territories against the aggressive actions of other packs," Wayne said. "Large packs get better at building armies of soldiers to defend their turf, and cooperative behavior and sociality are maintained by natural selection."

Wolves were re-introduced into Yellowstone Park in the mid-1990s and are rapidly becoming one of the best-studied carnivore populations in the world; they are turning out to be an excellent model for the study of sociality and cooperation, Wayne said.

Over many years of intensive collaborative study, former UCLA graduate student Dan Stahler (now a biologist with the National Park Service) and former UCLA postdoctoral scholar Bridgett vonHoldt (who worked in Wayne's laboratory and will soon become an assistant professor at Princeton University) analyzed genetic and life-history data on more than 300 gray wolves. They assessed survivorship and reproductive success, as well as the factors that influenced them, including body weight and pack size, among other variables. They found a striking association between pack size, body weight and offspring survival.

"We discovered that mother wolves' body weight and pack size play a crucial role in enabling pups to survive and thrive from birth to young adulthood," said Utah State University assistant professor of wildlife resources Dan MacNulty, a co-author of the study.

The research was funded by the National Science Foundation, the National Park Service and the Yellowstone Park Foundation, as well as private donors.

Environmental conditions that impact wolf reproduction, the researchers say, include resource availability, population density and disease prevalence -- especially deadly canine distemper, caused by a contagious virus to which pups are especially vulnerable.

In addition to body weight and pack size, the researchers examined the effects of maternal age and color (gray or black coat) and wolf population size on reproductive success.

"Each of these factors affects reproduction, but, overwhelmingly, female body weight and pack size are the main drivers of litter size and pup survival," said Stahler, the study's lead author. "Bigger females produce bigger litters; bigger packs are better equipped to hunt and defend pups and resources from competitors."

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Daniel R. Stahler, Daniel R. MacNulty, Robert K. Wayne, Bridgett vonHoldt, Douglas W. Smith. The adaptive value of morphological, behavioural and life-history traits in reproductive female wolves. Journal of Animal Ecology, 2012; DOI: 10.1111/j.1365-2656.2012.02039.x

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Urban coyotes never stray: New study finds 100 percent monogamy

Sep. 25, 2012 — Coyotes living in cities don't ever stray from their mates, and stay with each other till death do them part, according to a new study.

The finding sheds light on why the North American cousin of the dog and wolf, which is originally native to deserts and plains, is thriving today in urban areas.

Scientists with Ohio State University who genetically sampled 236 coyotes in the Chicago area over a six-year period found no evidence of polygamy -- of the animals having more than one mate -- nor of one mate ever leaving another while the other was still alive.

This was even though the coyotes exist in high population densities and have plenty of food to eat, which are conditions that often lead other dog family members, such as some fox species, to stray from their normal monogamy.

To cat around, as it were.

"I was surprised we didn't find any cheating going on," said study co-author Stan Gehrt, a wildlife ecologist with Ohio State's School of Environment and Natural Resources. "Even with all the opportunities for the coyotes to philander, they really don't.

"In contrast to studies of other presumably monogamous species that were later found to be cheating, such as arctic foxes and mountain bluebirds, we found incredible loyalty to partners in the study population."

The study appears in a recent issue of The Journal of Mammalogy.

The loyalty of coyotes to their mates may be a key to their success in urban areas, according to Gehrt.

Not only does a female coyote have the natural ability to produce large litters of young during times of abundance, such as when living in food-rich cities, she has a faithful partner to help raise them all.

"If the female were to try to raise those large litters by herself, she wouldn't be able to do it," said Gehrt, who holds appointments with the university's Ohio Agricultural Research and Development Center and Ohio State University Extension. "But the male spends just as much time helping to raise those pups as the female does."

Unlike the males of polygamous species, a male coyote "knows that every one of those pups is his offspring" and has a clear genetic stake in helping them survive, Gehrt said.

The research was done in Cook, Kane, DuPage and McHenry counties in northeast Illinois. All are in greater Chicago, which is home to about 9 million people and is the third-largest metropolitan area in the U.S.

It's also home to an estimated 1,000 to 2,000 coyotes. Gehrt has previously said he "couldn't find an area in Chicago where there weren't coyotes."

"You've got lots of coyotes in this landscape," said senior author Cecilia Hennessy, who conducted the study as a master's degree advisee of Gehrt and is now a doctoral student at Purdue University in Indiana. "You've got territories that abut each other. And coyotes can make long-distance forays. So you'd think, based on previous investigations of dog behavior, that cheating would be likely.

"But to find nothing, absolutely nothing, no evidence whatsoever of anything that wasn't monogamy, I was very surprised by that," she said.

The finding came through a wider study of Chicago-area coyotes that Gehrt has led since 2000. As the largest study ever on urban coyotes, it's a long-term effort to understand the animals' population ecology, how they adapt to urban life and how to reduce their conflicts with people.

"A powerful part of the new paper is that we have long-term field work, behavior observations, to accompany Cecilia's genetic work," Gehrt said. "So many genetic studies only analyze samples but know very little about their subjects, whereas we follow these individuals nearly every day and often to the completion of their lives. It's a nice mesh of lab and field work."

The scientists used live traps -- either padded foothold traps or non-choking neck snares -- to catch the coyotes for the study, although pups were simply dug from their dens and held by hand. Small blood and tissue samples were taken from all the animals. The adults, which were anesthetized, also were fitted with radio-collars for tracking their movements and ranges. Afterward, all the coyotes were released where they were caught.

Later, Hennessy, who previously was a plant genetics technician and biology major at the University of Cincinnati, used genetic techniques in the lab to test the animals' DNA and determine their family trees.

Coyotes maintain monogamy through long-term pair bonding, a term meaning an animal stays with the same mate for more than one breeding season, and sometimes for many.

A male coyote, for his part, practices diligent mate guarding -- keeping other males away from the female.

During estrus, which is the time when the female can become pregnant, the pair "will spend all their time together -- running, finding food, marking their territory. They'll always be right at each other's side."

"We've been able to follow some of these alpha pairs through time, and we've had some of them stay together for up to 10 years," Gehrt said. "They separate only upon the death of one of the individuals, so they truly adhere to that philosophy, 'Till death do us part,' " Hennessy said.

Funding was provided by the Cook County Animal and Rabies Control and by the Cook County Forest Preserve District, and by the Max McGraw Wildlife Foundation.

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The above story is reprinted from materials provided by Ohio State University. The original article was written by Kurt Knebusch.

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Journal Reference:

Hennessy, C. A., J. Dubach and S. D. Gehrt. Long-term pair bonding and genetic evidence for monogamy among urban coyotes (Canis latrans). Journal of Mammalogy, 93(3):732-742; 2012 [link]

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Onset of flu season raises concerns about human-to-pet transmission

Oct. 3, 2012 — As flu season approaches, people who get sick may not realize they can pass the flu not only to other humans, but possibly to other animals, including pets such as cats, dogs and ferrets.

This concept, called "reverse zoonosis," is still poorly understood but has raised concern among some scientists and veterinarians, who want to raise awareness and prevent further flu transmission to pets. About 80-100 million households in the United States have a cat or dog.

It's well known that new strains of influenza can evolve from animal populations such as pigs and birds and ultimately move into human populations, including the most recent influenza pandemic strain, H1N1. It's less appreciated, experts say, that humans appear to have passed the H1N1 flu to cats and other animals, some of which have died of respiratory illness.

There are only a handful of known cases of this phenomenon and the public health implications of reverse zoonosis of flu remain to be determined. But as a concern for veterinarians, it has raised troubling questions and so far, few answers.

Veterinary researchers at Oregon State University and Iowa State University are working to find more cases of this type of disease transmission and better understand any risks they pose to people and pets.

"We worry a lot about zoonoses, the transmission of diseases from animals to people," said Christiane Loehr, an associate professor in the OSU College of Veterinary Medicine. "But most people don't realize that humans can also pass diseases to animals, and this raises questions and concerns about mutations, new viral forms and evolving diseases that may potentially be zoonotic. And, of course, there is concern about the health of the animals."

The researchers are surveying flu transmission to household cat and dog populations, and suggest that people with influenza-like illness distance themselves from their pets. If a pet experiences respiratory disease or other illness following household exposure to someone with the influenza-like illness, the scientists encourage them to take the pet to a veterinarian for testing and treatment.

The first recorded, probable case of fatal human-to-cat transmission of the pandemic H1N1 flu virus occurred in Oregon in 2009, Loehr said. Details were published in Veterinary Pathology, a professional journal. In that instance, a pet owner became severely ill with the flu and had to be hospitalized. While she was still in the hospital, her cat -- an indoor cat with no exposure to other sick people, homes or wildlife -- also died of pneumonia caused by an H1N1 infection.

Since then, researchers have identified a total of 13 cats and one dog with pandemic H1N1 infection in 2011 and 2012 that appeared to have come from humans. Pet ferrets have also been shown to be infected, and some died. All of the animals' symptoms were similar to that of humans -- they rapidly develop severe respiratory disease, stop eating and some die. Serological studies suggest there is far more exposure to flu virus in cats and dogs than previously known.

"It's reasonable to assume there are many more cases of this than we know about, and we want to learn more," Loehr said. "Any time you have infection of a virus into a new species, it's a concern, a black box of uncertainty. We don't know for sure what the implications might be, but we do think this deserves more attention."

Natural and experimental transmission of the H3N2 influenza virus from dogs to cats in South Korea showed the potential for flu viruses to be transmitted among various animal species, Loehr said. It's unknown if an infected cat or other pet could pass influenza back to humans.

The primary concern in "reverse zoonosis," as in evolving flu viruses in more traditional hosts such as birds and swine, is that in any new movement of a virus from one species to another, the virus might mutate into a more virulent, harmful or easily transmissible form.

"All viruses can mutate, but the influenza virus raises special concern because it can change whole segments of its viral sequence fairly easily," Loehr said. "In terms of hosts and mutations, who's to say that the cat couldn't be the new pig? We'd just like to know more about this."

Veterinarians who encounter possible cases of this phenomenon can obtain more information from Loehr or Jessie Trujillo at Iowa State University. They are doing ongoing research to predict, prevent or curtail emergent events.

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Italian wolves prefer pork to venison

Dec. 20, 2012 — Some European wolves have a distinct preference for wild boar over other prey, according to new research.

Scientists from Durham University, UK, in collaboration with the University of Sassari in Italy, found that the diet of wolves was consistently dominated by the consumption of wild boar which accounted for about two thirds of total prey biomass, with roe deer accounting for around a third.

The study analysed the remains of prey items in almost 2000 samples of wolf dung over a nine year period and revealed that an increase in roe deer in the wolf diet only occurred in years when boar densities were very low. In years of high roe deer densities, the wolves still preferred to catch wild boar.

The results are published in the journal PLOS ONE.

The research team related the prey remains in wolf dung to the availability of possible prey in part of Tuscany, Italy -- an area recently colonised by wolves. The findings have implications for wildlife conservation as the impact of changing predator numbers on prey species is important for managing populations of both predators and prey.

Lead author, Miranda Davis, from the School of Biological and Biomedical Sciences at Durham University, said: "Our research demonstrates a consistent selection for wild boar among wolves in the study area, which could affect other prey species such as roe deer."

"Intriguingly, in other parts of Europe where red deer are also available, wolves appear to prefer this prey to wild boar, suggesting that they discriminate between different types of venison."

In Europe, the wolf (Canis lupis) is recovering from centuries of persecution and the expansion of wolf populations has the potential to change the ecology of communities of ungulates (hooved animals) by exposing them to natural predation by wolves, according to the researchers.

The preference for boar is in contrast to other areas of Europe where wolves often avoid boar as prey. One factor may be the relatively smaller size of Mediterranean boar, making them less dangerous to wolves in Mediterranean regions, compared to the larger-sized boar that roam other parts of Europe.

Co-author, Dr Stephen Willis, from the School of Biological and Biomedical Sciences at Durham University, said: "Wolves were hunted to extinction in the UK, probably by the end of the 17th century. Our findings from Italy suggest that if they were reintroduced into an area with a healthy ungulate population their impact on livestock could be minimal."

Tuscany's woodlands support populations of both roe deer and wild boar, and are also grazed by sheep, goats and cattle; however, wild boar and roe deer made up over 95 per cent of wolf diet in the study area, with very little evidence of livestock predation.

The scientists identified prey items from fragments of bones and hair in the wolf dung collected in the region. The prey categories included wild boar, roe deer, red deer, hare, small rodents, goats, sheep and cattle.

For more than five years of the study, the percentage of wolf diet made up of wild boar was more than twice that of roe deer. Other prey represented only a very small proportion of the diet.

The researchers believe that further dietary studies are essential for understanding the true impact of wolves on European wildlife over time.

Co-author, Dr Phil Stephens, from the School of Biological and Biomedical Sciences at Durham University added: "Wolves and brown bears are gradually returning to their former strongholds in Europe. Understanding the needs of these species, as well as their potential impacts, is going to be fundamental to managing that welcome return."

The project was part-funded by a Durham University Doctoral Fellowship and the Regional Government of Tuscany and the Province of Arezzo also provided logistical support throughout the study.

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Journal Reference:

Miranda L. Davis, Philip A. Stephens, Stephen G. Willis, Elena Bassi, Andrea Marcon, Emanuela Donaggio, Claudia Capitani, Marco Apollonio. Prey Selection by an Apex Predator: The Importance of Sampling Uncertainty. PLoS ONE, 2012; 7 (10): e47894 DOI: 10.1371/journal.pone.0047894

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Call that a ball? Dogs learn to associate words with objects differently than humans do

Nov. 21, 2012 — Dogs learning to associate words with objects form these associations in different ways than humans do, according to research published Nov. 21 in the open access journal PLOS ONE by Emile van der Zee and colleagues from the University of Lincoln, UK.

Previous studies have shown that humans between the ages of two to three typically learn to associate words with the shapes of objects, rather than their size or texture. For example, toddlers who learn what a 'ball' is and are then presented other objects with similar shapes, sizes or textures will identify a similarly-shaped object as 'ball', rather than one of the same size or texture.

Earlier research with dogs has shown that they can learn to associate words with categories of objects (such as 'toy'), but whether their learning process was the same as that of humans was unknown.

In this new study, the scientists presented Gable, a five year old Border Collie, with similar choices to see if this 'shape bias' exists in dogs. They found that after a brief training period, Gable learned to associate the name of an object with its size, identifying other objects of similar size by the same name. After a longer period of exposure to both a name and an object, the dog learned to associate a word to other objects of similar textures, but not to objects of similar shape.

According to the authors, these results suggest that dogs (or at least Gable) process and associate words with objects in qualitatively different ways than humans do. They add that this may be due to differences in how evolutionary history has shaped human and dog senses of perceiving shape, texture or size.

The bottom line: Though your dog understands the command "Fetch the ball," but he may think of the object in a very different way than you do when he hears it. As the authors explain, "Where shape matters for us, size or texture matters more for your dog. This study shows for the first time that there is a qualitative difference in word comprehension in the dog compared to word comprehension in humans."

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van der Zee E, Zulch H, Mills D. Word Generalization by a Dog (Canis familiaris): Is Shape Important? PLoS ONE, 7(11): e49382 DOI: 10.1371/journal.pone.0049382

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Obese dogs at risk of health condition experienced by humans

Oct. 31, 2012 — Veterinary scientists at the University of Liverpool have found that, like humans, obese dogs can experience metabolic syndrome, a condition that describes multiple health issues that occur in the body at the same time.

The condition occurs when a number of health problems, such as increased blood glucose and increased cholesterol levels, develop together, with the potential to increase the risk of other diseases, such as cardiovascular disease and diabetes.

Although canine obesity is known to cause insulin resistance, mild hypertension, and high blood cholesterol levels, it has not, until now, been investigated for links to metabolic syndrome, which is common in obese humans.

In a study involving 35 obese dogs, 20% were found to have metabolic syndrome. Similar to humans with the condition, obese dogs had increased blood insulin, suggested that the pancreas is working harder than normal to control blood glucose. Blood adiponectin, a protein produced by fat cells that helps control sugars and fats, was also at lower levels than normal. It is yet to be determined, however, what the exact health impacts of these issues are on dogs, and if they are similar to the diseases that metabolic syndrome can cause in humans.

The team demonstrated, however, that the metabolic abnormalities identified in obese dogs, improved when they successfully lost weight.

Dr Alex German, from the University's Department of Obesity and Endocrinology, said: "It is estimated that one third to a half of the UK dog population is overweight. A previous study that we conducted showed that a dog's quality of life improved with weight loss, resulting in better vitality and reduced emotional distress.

"This new research creates a lot of new questions for us. It suggests that dogs develop metabolic syndrome, similar to humans with obesity-related health problems. We now need to investigate, however, what health consequences this may have for dogs. The key point for us is that the problem can be resolved with successful weight loss, and this must be a priority for pet owners with obese dogs."

The study is published in the BMC Veterinary Research.

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Asta Tvarijonaviciute, Jose J Ceron, Shelley L Holden, Daniel J Cuthbertson, Vincent Biourge, Penelope J Morris, Alexander J German. Obesity-related metabolic dysfunction in dogs: a comparison with human metabolic syndrome. BMC Veterinary Research, 2012; 8 (1): 147 DOI: 10.1186/1746-6148-8-147

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Nanotech device mimics dog's nose to detect explosives

Nov. 20, 2012 — Portable, accurate, and highly sensitive devices that sniff out vapors from explosives and other substances could become as commonplace as smoke detectors in public places, thanks to researchers at University of California, Santa Barbara.

Researchers at UCSB, led by professors Carl Meinhart of mechanical engineering and Martin Moskovits of chemistry, have designed a detector that uses microfluidic nanotechnology to mimic the biological mechanism behind canine scent receptors. The device is both highly sensitive to trace amounts of certain vapor molecules, and able to tell a specific substance apart from similar molecules.

"Dogs are still the gold standard for scent detection of explosives. But like a person, a dog can have a good day or a bad day, get tired or distracted," said Meinhart. "We have developed a device with the same or better sensitivity as a dog's nose that feeds into a computer to report exactly what kind of molecule it's detecting." The key to their technology, explained Meinhart, is in the merging of principles from mechanical engineering and chemistry in a collaboration made possible by UCSB's Institute for Collaborative Biotechnologies.

Results published this month in Analytical Chemistry show that their device can detect airborne molecules of a chemical called 2,4-dinitrotoluene, the primary vapor emanating from TNT-based explosives. The human nose cannot detect such minute amounts of a substance, but "sniffer" dogs have long been used to track these types of molecules. Their technology is inspired by the biological design and microscale size of the canine olfactory mucus layer, which absorbs and then concentrates airborne molecules.

"The device is capable of real-time detection and identification of certain types of molecules at concentrations of 1 ppb or below. Its specificity and sensitivity are unparalleled," said Dr. Brian Piorek, former mechanical engineering doctoral student in Meinhart's laboratory and Chief Scientist at Santa Barbara-based SpectraFluidics, Inc . The technology has been patented and exclusively licensed to SpectraFluidics, a company that Piorek co-founded in 2008 with private investors.

"Our research project not only brings different disciplines together to develop something new, but it also creates jobs for the local community and hopefully benefits society in general," commented Meinhart.

Packaged on a fingerprint-sized silicon microchip and fabricated at UCSB's state-of-the-art cleanroom facility, the underlying technology combines free-surface microfluidics and surface-enhanced Raman spectroscopy (SERS) to capture and identify molecules. A microscale channel of liquid absorbs and concentrates the molecules by up to six orders of magnitude. Once the vapor molecules are absorbed into the microchannel, they interact with nanoparticles that amplify their spectral signature when excited by laser light. A computer database of spectral signatures identifies what kind of molecule has been captured.

"The device consists of two parts," explained Moskovits. "There's a microchannel, which is like a tiny river that we use to trap the molecules and present them to the other part, a mini spectrometer powered by a laser that detects them. These microchannels are twenty times smaller than the thickness of a human hair."

"The technology could be used to detect a very wide variety of molecules," said Meinhart. "The applications could extend to certain disease diagnosis or narcotics detection, to name a few."

Moskovits added, "The paper we published focused on explosives, but it doesn't have to be explosives. It could detect molecules from someone's breath that may indicate disease, for example, or food that has spoiled."

The fundamental research was developed through an interdisciplinary collaboration between Professors Meinhart and Moskovits, and carried out by former doctoral researchers Dr. Piorek and Dr. Seung-Joon Lee. Their project was funded in part by UCSB's Institute for Collaborative Biotechnologies through the Army Research Office and DARPA.

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Brian D. Piorek, Seung Joon Lee, Martin Moskovits, Carl D. Meinhart. Free-Surface Microfluidics/Surface-Enhanced Raman Spectroscopy for Real-Time Trace Vapor Detection of Explosives. Analytical Chemistry, 2012; 84 (22): 9700 DOI: 10.1021/ac302497y

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Virus-host co-evolution: How specialized should a strain of a multi-host virus be?

Dec. 11, 2012 — A new study of canine distemper virus (CDV) provides the first evidence that the virus occurs as specialist strains that emerge in response to strong evolutionary selection in the large global domestic dog population, and as generalist strains adapted to infect a broad range of carnivore species that occur as smaller host populations. The study not only unravelled one key mechanism which led to the evolution of specialist and generalist strains, it also showed that specialising on one host species comes at the cost of a reduced ability to infect other host species.

Scientists from the Leibniz Institute for Zoo and Wildlife Research (IZW), the Freie Universität Berlin and the University of Göttingen in Germany, the INRS-Institut Armand-Frappier in Canada and Cornell University in USA investigated the 'lock and key' mechanism used by the canine distemper virus (CDV) to gain entry into host cells. In the case of CDV, this mechanism involves the binding of a specific protein of the virus (the CDV haemagglutinin protein, CDV-H) to a specific receptor molecule on the host cell (the signalling lymphocytic activation molecule, SLAM). The authors investigated differences between SLAM receptors in wild and domestic carnivore species. This revealed that SLAM receptors from different species in the dog family (Canidae) were quite similar but that they differed substantially from those of species in other carnivore families such as the cats (Felidae), hyenas (Hyaenidae), martens (Mustelidae), seals (Phocidae) and walruses (Odobenidae). "As the configuration of the 'lock' on the host cell varies considerably between dogs and their close relatives on the one hand and carnivores from other families on the other, we expected that the 'key' used by different strains of CDV to gain entry to host cells would also show variation. Viruses constantly adapt to improve their ability to infect their different host species" comments Klaus Osterrieder (FU Berlin).

The researchers then used cell cultures to investigate the ability of CDV-H proteins from different domestic dog and non-dog strains to gain entry into host cells. This suite of experiments revealed that CDV-H proteins from domestic dog strains performed much better in cell cultures with SLAM receptors from domestic dogs than in cell cultures with SLAM receptors from the African lion or the domestic cat. In other words they exhibited specialist traits. CDV-H proteins from non-dog CDV strains exhibited generalist traits because they performed equally well regardless of which host species SLAM receptor (African lion, domestic cat or domestic dog) was offered to them. Furthermore, as expected of generalists, CDV-H proteins from non-dog strains performed less well in cells that expressed domestic dog SLAM receptors than did CDV-H proteins from domestic dog strains. This variation in performance was not limited to cell entry. It was also found in a further set of cell culture experiments in which either domestic dog and non-dog strains replicated inside cells expressing either domestic dog or non-dog SLAM receptors.

"Gaining entry into host cells with the right 'key' is crucial for successful infection of a host. We therefore wanted to know whether by substituting the amino acid at one specific site in the CDV-H protein previously suggested to be an important component of the 'key' of a specialist strain for the amino acid at this site in non-dog strains would reduce the ability of a dog strain to gain entry into its preferred host, the domestic dog, and simultaneously improve its ability to gain entry into other carnivores" states Veljko Nikolin from the IZW. The research team therefore investigated the functional importance of one amino acid site (549) in the CDV-H protein in different host receptor environments, because this site was known to be under strong positive selection. Domestic dog strains had been previously observed to mostly have the amino acid tyrosine at this site whereas non-dog strains typically had the amino acid histidine at this location. The team found that substituting tyrosine by histidine at site 549 in the CDV-H protein of one dog strain decreased expression of specialist traits and increased expression of generalist traits, thereby confirming the importance of this particular site.

The new findings add substantially to current knowledge on CDV epidemiology by providing evidence for the expression of specialist and generalist traits by CDV strains, unravelling its mechanism and demonstrating fitness trade-offs across carnivore host environments. "There has been a common assumption that canine distemper first evolved in domestic dogs and then spilled over into wild carnivores. Whilst our results are compatible with this idea they also support an alternative explanation -- namely that canine distemper virus was originally a generalist virus in wild carnivores and then later specialist strains evolved as the domestic dog population rapidly expanded together with the human population, thereby providing conditions favourable for strong co-evolution within a homogeneous host environment" explains Marion East, the senior author of the study.

Despite effective vaccines against CDV epidemics regularly occur in domestic dogs in many countries worldwide. CDV infection has been reported in a wide range of wild carnivore species both in free-ranging populations and zoo animals. Clinical signs of CDV include neurological disorders, nasal discharge, high fever, fatigue, and diarrhea.

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Veljko M. Nikolin, Klaus Osterrieder, Veronika von Messling, Heribert Hofer, Danielle Anderson, Edward Dubovi, Edgar Brunner, Marion L. East. Antagonistic Pleiotropy and Fitness Trade-Offs Reveal Specialist and Generalist Traits in Strains of Canine Distemper Virus. PLoS ONE, 2012; 7 (12): e50955 DOI: 10.1371/journal.pone.0050955

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Fetch! First clear evidence that dogs do not naturally distinguish objects by shape

Nov. 22, 2012 — Researchers have provided the first empirical evidence that the way in which dogs relate words to objects is fundamentally different to humans.

Many pet owners marvel at their dog's ability to fetch different objects such as toys on instruction, perceiving this as evidence that the dog 'understands' these words in a similar way to us.

Psychologists and animal behaviour specialists from the University of Lincoln in the UK have shown through a series of unique behavioural experiments that the mental lexicon of domestic dogs is constructed in a substantially different manner to our own.

The findings, published in the peer-reviewed online journal PLOS ONE, may help to advance understanding of the foundations of language in humans and the critical differences with other species.

From the onset of word learning, young children generalise names to new objects on the basis of shape, and continue to do so as adults -- a tendency known as 'shape bias'. This is crucial to language development because it enables children to assign new objects to pre-established classes -- for example, to recognise that a tennis ball and a football both belong to the category 'ball'.

The Lincoln researchers found that when dogs are introduced to new words to refer to new objects, they first generalise based on object size, then on object texture. Unlike humans, they do not appear to naturally discriminate based on shape.

The study was conducted by Dr Emile van der Zee from the University of Lincoln's School of Psychology with Helen Zulch and Professor Daniel Mills from the University's School of Life Sciences.

Dr van der Zee said: "A number of recent studies have suggested that the domestic dog's word comprehension is human-like. Arguments have been made to refute this claim but until now there has been no clear empirical evidence to resolve the debate. Our findings bring a fundamental new insight into this discussion and add to our understanding of the cognitive equipment necessary for true human word learning."

Dr van der Zee and his colleagues worked with a five-year-old border collie called Gable who had shown remarkable abilities to learn new object words.

They devised four different challenges for Gable to determine the extent and nature of his word comprehension.

On a number of occasions a selection of ten different objects known to Gable were placed in an enclosure out of sight of Gable and the researchers, and he was then given a verbal instruction to fetch a particular object from the ten.

Initial tests confirmed that Gable could easily distinguish between toys he knew well.

It was when the researchers introduced new words and novel objects of varying shape, size and texture that Gable began to reveal the absence of shape bias in his choices.

He appeared to make distinctions based first on object size, then, when he had longer to become familiar with the new objects, on the basis of texture. Object shape appeared to have no influence.

The researchers concluded that the mental lexicon -- the long-term mental store containing sound-to-meaning mappings -- appears to be fundamentally different in dogs and humans, both in terms of how it is built (word knowledge development) and in how it operates (word reference quality).

Dr van der Zee added: "This would suggest that an important factor in the natural structuring of the mental lexicon may be the way in which sensory information is organised in a particular species. The human visual system is tuned to detect object shape for the purpose of object recognition. In our experiments we excluded Gable using scent cues. It seems that his visual system and sensory cues linked to his mouth region are focused not on shape, but on size and texture. Only future experiments will reveal what role scent plays for the dog in generalising words. It is only by comparing other species with humans that we can find out more about the neural and genetic foundations of word reference in language."

Besides the significance for researchers interested in the roots of language development, awareness of the absence of shape bias in dogs may also inform refinements to the training programmes for pets, working dogs or assistance animals.

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Emile van der Zee, Helen Zulch, Daniel Mills. Word Generalization by a Dog (Canis familiaris): Is Shape Important? PLoS ONE, 2012; 7 (11): e49382 DOI: 10.1371/journal.pone.0049382

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Puppies don't pick up on yawns: Dogs, like humans, show a gradual development of susceptibility to contagious yawning

Oct. 23, 2012 — Do you get tired when others yawn? Does your dog get tired when you yawn? New research from Lund University in Sweden establishes that dogs catch yawns from humans. But not if the dogs are too young. The study, published in Springer's journal Animal Cognition, found that, like humans, dogs show a developmental trend in susceptibility to contagious yawning. While dogs above seven months of age catch human yawns, younger dogs are immune to yawn contagion.

Contagious yawning is not just a sign of sleepiness or boredom. Previous research has shown contagious yawning in humans, adult chimpanzees, baboons and dogs, and suggests that it can be used as a measure of empathy. Empathy, mimicking the emotional responses of others, is difficult to measure directly, but contagious yawning allows assessment of a behavioral empathetic response, the researchers say.

While the development of contagious yawning in human children has seen much research, this is the first study to investigate its development in another species.

Elainie Alenkær Madsen, PhD, and Tomas Persson, PhD, researchers at Lund University, engaged 35 dogs in Denmark, aged between four and 14 months, in bouts of play and cuddling and observed the dogs' responses when a human repeatedly yawned or gaped or performed neither of the two expressions. Only dogs above seven months of age showed evidence of contagious yawning.

This pattern of development is consistent with that in humans, who also show a developmental increase in susceptibility to yawn contagion, with children typically beginning to yawn contagiously at the age of four, when a number of cognitive abilities, such as accurate identification of others' emotions, begin to clearly manifest. One interpretation that Madsen and Persson suggest is that the results reflect a general developmental pattern, shared by humans and other animals, in terms of affective empathy and the ability to identify others' emotions. Given that contagious yawning may be an empathetic response, the results suggest that empathy and the mimicry that may underlie it develop slowly over the first year of a dog's life.

There was some evidence that the researchers may have transferred the emotion that yawning reflects (sleepiness) to the dogs, as nearly half of the dogs responded to yawning with a reduction in arousal, to the extent that the experimenter needed to prevent a number of dogs from falling asleep.

Research with adult humans and other primates suggest that individuals are more likely to yawn contagiously to those with whom they have close emotional bonds. Madsen and Persson tested the dogs with both an unfamiliar experimenter and their owner, but found no evidence that the puppies preferentially yawned in response to the yawns of the human with whom they were emotionally close. Since this is also the case for young human children, the researchers suggest that in species that show an empathy-based social modulatory effect on contagious yawning, this behavior only emerges at later stages of development.

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Dogs can accurately sniff out 'superbug' infections

Dec. 13, 2012 — Dogs can sniff out Clostridium difficile (the infective agent that is responsible for many of the dreaded "hospital acquired infections") in stool samples and even in the air surrounding patients in hospital with a very high degree of accuracy, finds a study in the Christmas issue published on bmj.com today.

The findings support previous studies of dogs detecting various types of cancer and could have great potential for screening hospital wards to help prevent C. difficile outbreaks, say the researchers.

C. difficile infection most commonly occurs in older people who have recently had a course of antibiotics in hospital, but it can also start in the community, especially in care homes. Symptoms can range from mild diarrhoea to a life-threatening inflammation of the bowel.

Early detection is vital to prevent transmission, but diagnostic tests can be expensive and slow, which can delay treatment for up to a week.

Diarrhoea due to C. difficile has a specific smell, and dogs have a superior sense of smell compared with humans. This prompted researchers in the Netherlands to investigate whether a dog could be trained to detect C. difficile.

A two-year old male beagle (called Cliff) was trained by a professional instructor to identify C. difficile in stool samples and in patients with C. difficile infection. He was taught to indicate the presence of the specific scent by sitting or lying down.

The dog had not been trained for detection purposes before.

After two months of training, the dog's detection abilities were formally tested on 50 C. difficile positive and 50 C. difficile negative stool samples. He correctly identified all 50 positive samples and 47 out of 50 negative samples.

This equates to 100% sensitivity and 94% specificity (sensitivity measures the proportion of positives correctly identified, while specificity measures the proportion of negatives correctly identified).

The dog was then taken onto two hospital wards to test his detection abilities in patients. He correctly identified 25 out of 30 cases (sensitivity 83%) and 265 out of 270 negative controls (specificity 98%).

The researchers add that the dog was quick and efficient, screening a complete hospital ward for the presence of patients with C. difficile infection in less than 10 minutes.

They point to some study limitations, such as the unpredictability of using an animal as a diagnostic tool and the potential for spreading infections via the dog, and say some unanswered questions remain.

However, they say their study demonstrates that a detection dog can be trained to identify C. difficile infection with a high degree of accuracy, both in stool samples and in hospitalised patients. "This could have great potential for C. difficile infection screening in healthcare facilities and thus contribute to C. difficile infection outbreak control and prevention," they conclude.

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M. K. Bomers, M. A. van Agtmael, H. Luik, M. C. van Veen, C. M. J. E. Vandenbroucke-Grauls, Y. M. Smulders. Using a dog's superior olfactory sensitivity to identify Clostridium difficile in stools and patients: proof of principle study. BMJ, 2012; 345 (dec13 8): e7396 DOI: 10.1136/bmj.e7396

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Researchers find first evidence of Ice Age wolves in Nevada

Dec. 13, 2012 — A University of Nevada, Las Vegas research team recently unearthed fossil remains from an extinct wolf species in a wash northwest of Las Vegas, revealing the first evidence that the Ice Age mammal once lived in Nevada.

The metapodial, or foot bone, was uncovered late last year by UNLV geologist Josh Bonde during a survey of the Upper Las Vegas Wash. They have now confirmed that the bone comes from a dire wolf.

The discovery site is near the proposed Tule Springs Fossil Beds National Monument, a fossil-rich area known for its diversity and abundance of Ice Age animal remains. Scientists estimate the fossil to be 10,000 to 15,000 years old during the Late Pleistocene period.

"Dire wolves are known to have lived in almost all of North America south of Canada, but their historical presence in Nevada has been absent until now," said Bonde, a UNLV geology professor. He was a Ph.D. student at the university when he discovered the bone.

"The Tule Springs area has turned up many species, but it's exciting to fill in another part of the map for this animal and reveal a bit more about the Ice Age ecosystem in Southern Nevada."

The dire wolf, a larger relative of the gray wolf, was present in much of North and South America for more than a million years. Scientists theorize that competition from other wolf species and a possible food scarcity led to its extinction roughly 10,000 years ago.

Foot bones of the extinct dire wolf are difficult to distinguish from those of the gray wolf. Researchers conclude bone is likely from a dire wolf because of the abundance of dire wolf fossils?and scarcity of gray wolf fossils?in similar-aged excavation sites throughout the Southwest.

Fossil remains of dire wolves are abundant in the La Brea tar pits and have been found in other Southwestern states. Many of the same species of Ice Age animals found at La Brea have also been recovered in the Las Vegas Valley, including Columbian mammoths, camels, horses, bison, and ground sloths.

"This discovery helps flesh out Southern Nevada's Pleistocene ecosystem and shows that there are still important discoveries to be made in the Upper Las Vegas Wash," said UNLV geology professor Steve Rowland, a collaborator with Bonde on the study of local Ice Age fossils. "To understand why certain species became extinct and others did not, we need to learn as much as possible about predatory habits and which species were especially sensitive to changes in the environment."

The announcement comes on the heels of a recent discovery in the same wash of a saber-tooth cat by researchers from the San Bernardino County Museum. Like dire wolves, saber-tooth cats were Pleistocene predators that had been conspicuously absent from the Southern Nevada fossil record.

According to Rowland, Tule Springs was a spring-fed, swampy area during periods of the Late Pleistocene, an ideal spot for plant-eating animals and their carnivorous predators.

The recent discoveries come exactly 50 years after scientists conducted a 'big dig' at Tule Springs, revealing the site to be rich with Ice Age fossils.

"Tule Springs likely had the highest density of large animals in the area during the Late Pleistocene, and the marshy environment was very good for preserving at least some of the bones and teeth of animals that died there," said Rowland.

"In the 50 years since the 'big dig,' the scientists have confirmed that humans interacted with Ice Age animals. We now have a new list of questions about life and death in the Pleistocene, and a new tool kit of research techniques to help us get the answers."

The identity of the find was confirmed by Xiaoming Wang of the Los Angeles County Museum of Natural History, an expert on extinct species of the dog family. Bonde has been surveying the Tule Springs area since 2007, and he and a group of UNLV undergraduate studentss are prospecting for more fossils.

The center of the original 'big dig' is on the same parcel of land where Bonde discovered the wolf fossil.

The dire wolf bone, in addition to other bones collected by UNLV researchers, are cataloged, studied, and stored at UNLV.

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Man's best friend: Common canine virus may lead to new vaccines for deadly human diseases

Nov. 27, 2012 — Researchers at the University of Georgia have discovered that a virus commonly found in dogs may serve as the foundation for the next great breakthrough in human vaccine development.

Although harmless in humans, parainfluenza virus 5, or PIV5, is thought to contribute to upper respiratory infections in dogs, and it is a common target for canine vaccines designed to prevent kennel cough. In a paper published recently in PLOS ONE, researchers describe how this virus could be used in humans to protect against diseases that have eluded vaccine efforts for decades.

"We can use this virus as a vector for all kinds of pathogens that are difficult to vaccinate against," said Biao He, the study's principal investigator and professor of infectious diseases in UGA's College of Veterinary Medicine. "We have developed a very strong H5N1 flu vaccine with this technique, but we are also working on vaccines for HIV, tuberculosis and malaria."

PIV5 does not cause disease in humans, as our immune system is able to recognize and destroy it. By placing antigens from other viruses or parasites inside PIV5, it effectively becomes a delivery vehicle that exposes the human immune system to important pathogens and allows it to create the antibodies that will protect against future infection.

This approach not only ensures full exposure to the vaccine but also is much safer because it does not require the use of attenuated, or weakened, pathogens. For example, an HIV vaccine delivered by PIV5 would contain only those parts of the HIV virus necessary to create immunity, making it impossible to contract the disease from the vaccine.

"Safety is always our number one concern," said He, who is also a Georgia Research Alliance distinguished investigator and member of the Faculty of Infectious Diseases. "PIV5 makes it much easier to vaccinate without having to use live pathogens."

Using viruses as a delivery mechanism for vaccines is not a new technique, but previous efforts have been fraught with difficulty. If humans or animals already possess a strong immunity to the virus used for delivery, the vaccine is unlikely to work, as it will be destroyed by the immune system too quickly.

"Pre-existing immunity to viruses is the main reason most of these vaccines fail," He said.

But in this latest study, He and his colleagues demonstrate that immunity to PIV5 does not limit its effectiveness as a vaccine delivery mechanism, even though many animals-including humans- already carry antibodies against it.

In their experiments, the researchers found that a single dose inoculation using PIV5 protected mice from the influenza strain that causes seasonal flu. Another single dose experimental vaccine also protected mice from the highly pathogenic and deadly H5N1 virus commonly known as bird flu.

This recent work is a culmination of more than fifteen years of research and experimentation with the PIV5 virus, and He has confidence that it will serve as an excellent foundation for vaccines to treat diseases in both animals and humans.

"I believe we have the best H5N1 vaccine candidate in existence," He said. "But we have also opened up a big field for a host of new vaccines."

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Zhenhai Chen, Pei Xu, Gregory W. Salyards, Stephen B. Harvey, Balazs Rada, Zhen F. Fu, Biao He. Evaluating a Parainfluenza Virus 5-Based Vaccine in a Host with Pre-Existing Immunity against Parainfluenza Virus 5. PLoS ONE, 2012; 7 (11): e50144 DOI: 10.1371/journal.pone.0050144

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Call for global monitoring of infectious diseases in dogs and cats

Nov. 12, 2012 — Most emerging infectious diseases of humans come from animals. International health agencies monitor these diseases, but they do so only for humans and livestock, not for companion dogs and cats. A new study recommends a global system is needed to monitor infectious diseases of companion dogs and cats.

The study, led by Michael Day, Professor of Veterinary Pathology in the School of Veterinary Sciences at the University of Bristol and published online in Emerging Infectious Diseases, lists key infectious diseases that may be transmitted between dogs and cats and man ('zoonotic diseases'). It is well recognised that most of the major new diseases of humankind will have an animal origin and dogs and cats are a potential source of such 'emerging diseases'.

The World Small Animal Veterinary Association (WSAVA) One Health Committee, which promotes the closer integration of human and animal healthcare ('One Health') in collaboration with the US Centers for Disease Control and Prevention (CDC), the World Organisation for Animal Health (OIE) and the World Health Organization (WHO), recommends in the paper a co-ordinated global disease monitoring system is established for veterinarians who work in small companion animal practice.

However, development of such a scheme would require significant political will, scientific application and financial support that could be achieved through a public-private partnership. The knowledge gained through surveillance would permit more effective global control of small companion animal zoonoses and so reduce the risks inherent within this most fundamental of human relationships.

Canine rabies virus infection, one of the diseases listed in the paper, is estimated to kill a minimum of 55,000 people in Africa and Asia each year.

Michael Day, Professor of Veterinary Pathology in the School of Veterinary Sciences, said: "The number of small companion animals is significant. For example there are an estimated eight to ten million dogs living in up to 31 per cent of UK homes and in the USA, 72 million dogs in 37 per cent of homes.

"In developed countries the relationship between man and dogs and cats has deepened, with these animals now closely sharing the human indoor environment. The benefits of pet ownership on human health, well-being and development are unquestionable, but as dogs and cats have moved from the barn, to the house, to the bedroom, the potential for disease spread to humans increases. Control of diseases among dogs and cats is a good way to prevent spread to humans."

Small companion animals, most typically dogs and cats, are kept by people for companionship or a range of utilitarian purposes. Dogs and cats have a close relationship with their human owners and play an important role in the cultures of both developed and developing communities. The social and societal benefits of pet ownership are significant, with dogs now participating in programmes in institutions such as schools, prisons and hospitals, in addition to their role in family life.

In human, livestock and wildlife heath there are programmes of active surveillance for infectious disease, which monitor the global distribution and movement of key infectious agents. For example, the WHO monitors human influenza virus infection through a network of 111 centres in 83 countries. In contrast, there is no such monitoring for the infections that may be transmitted between small companion animals and man.

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The above story is reprinted from materials provided by University of Bristol.

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Michael J. Day, Edward Breitschwerdt, Sarah Cleaveland, Umesh Karkare, Chand Khanna, Jolle Kirpensteijn, Thijs Kuiken, Michael R. Lappin, Jennifer McQuiston, Elizabeth Mumford, Tanya Myers, Clarisa B. Palatnik-de-Sousa, Carol Rubin, Gregg Takashima, Alex Thiermann. Surveillance of Zoonotic Infectious Disease Transmitted by Small Companion Animals. Emerging Infectious Diseases, 2012; 18 (12) DOI: 10.3201/eid1812.120664

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BPA in dog training aids: High estrogen-mimicking chemical concentrations found in dog training batons

Dec. 10, 2012 — Sometimes orange, sometimes white, dog trainers often use plastic fetching batons called bumpers to teach dogs how to retrieve. But researchers at Texas Tech University have discovered that the dogs also may fetch a mouthful of potentially dangerous chemicals at the same time.

Researchers also found these chemicals, though at significantly lower concentrations, in a multitude of plastic chew toys purchased from a pet store.

The research was conducted by Kimberly Wooten, a master's student using the project as her thesis, and Phil Smith, an associate professor of terrestrial ecotoxicology at The Institute of Environmental and Human Health at Texas Tech. Though unpublished, Wooten presented the results at the Society of Environmental Toxicology and Chemistry conference held in California.

"I raise and train Labrador retrievers and hunt with them as well," Smith said, explaining what inspired him and Wooten to conduct the experiments. "In the process of training a lab, you do a lot of work with these plastic bumpers. I have a lot of bumpers in my garage, and they spend a lot of time in the mouths of my retrievers. Well, lots of attention has been given to chemicals in plastics lately regarding their effects on humans. Since we all care about our dogs, and we want them to be as healthy and smart and well-behaved as possible, we decided to look into this."

Wooten and Smith said they predicted the possibility that the bumpers could leach phthalates and bisphenol A (BPA), which are used to give elasticity to plastic and vinyl and are known endocrine disruptors that mimic estrogen or act as anti-androgens and could lead to negative health effects. However, both said the findings have created more questions than answers because hardly any data exists on long-term effects of these chemicals on man's best friend.

"The whole end goal was to answer the questions, 'What does this mean for my pet? Is this a concern for our health?'" Wooten said. "We don't have a good answer yet because there's no good data to compare to our findings."

To test for the chemicals, Wooten and Smith created simulated dog saliva, then simulated chewing by squeezing the bumpers and dog toys with stainless steel salad tongs.

Some bumpers and toys were weathered outside as well to see if older toys gave off more chemicals, Smith said.

"We found that the aging or weathering the toys increased concentrations of BPA and phthalates," Smith said. "The toys had lower concentrations of phthalates than the bumpers, so that's good news. But they also had some other chemicals that mimicked estrogen. We need to find out what those are."

Wooten said BPA and phthalates can have effects on developing fetuses and can have a lifelong effect on offspring on lab animals. Some studies on humans conclude that BPA poses no health risks while others cite a number of adverse effects. Because of this, the U.S. government banned the use of BPA in baby bottles in 2012.

Wooten said questions still remain also as to how much of a dose a dog may get from playing with the bumpers, since it was difficult to say how much of these chemicals may actually leach out into a dog's mouth.

"The interaction of pet health and environmental chemicals is understudied," Wooten said. "What may be a safe dose for one species isn't always a good measure for another species. But the amount of BPA and phthalates we found from the bumpers would be considered on the high end of what you might find in children's toys."

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The above story is reprinted from materials provided by Texas Tech University, via Newswise.

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