. Scientific Frontline: Veterinary
Showing posts with label Veterinary. Show all posts
Showing posts with label Veterinary. Show all posts

Sunday, February 5, 2023

Rates of hatching failure in birds almost twice as high as previously estimated

Hatching failure rates in birds are almost twice as high as experts previously estimated, according to the largest ever study of its kind.
Photo Credit: Michaela Wenzler

New study from the University of Sheffield, IoZ, and UCL found more than one in six bird eggs fail to hatch. Hatching failure increases as species decline, so the new research could be used to predict what species are most at risk of extinction.

The work provides evidence that conservation managers can use to support their decision making, creating the best possible outcomes for threatened bird species recovery.

The new report highlights how conservationists can best support the recovery of threatened bird species, as it outlines how different conservation practices may affect hatching rates.

Researchers from the University of Sheffield, Institute of Zoology, and University College London (UCL) looked at 241 bird species across 231 previous studies to examine hatching failure. They found that nearly 17 per cent of bird eggs fail to hatch - almost double the figure reported 40 years ago of just over nine per cent.

Tuesday, January 31, 2023

Deer carry SARS-CoV-2 variants that are extinct in humans

White-tailed deer
Photo Credit: Heidi-Ann Fourkiller | SFLORG

White-tailed deer ­– the most abundant large mammal in North America – are harboring SARS-CoV-2 variants that once widely circulated but are no longer found in humans.

Whether or not deer could act as long-term reservoirs for these variants that have become obsolete in people is unknown, as scientists need more time and study to verify if it’s true.

The study, “White-tailed Deer (Odocoileus virginianus) May Serve as a Wildlife Reservoir for Nearly Extinct SARS-CoV-2 Variants of Concern,” which published Jan. 31 in the journal Proceedings of the National Academy of Sciences, represents one of the most comprehensive studies to date to assess the prevalence, genetic diversity and evolution of SARS-CoV-2 in white-tailed deer. The study focused on the white-tailed deer population in New York.

“One of the most striking findings of this study was the detection of co-circulation of three variants of concern – alpha, gamma and delta – in this wild animal population,” said Dr. Diego Diel, associate professor in the Department of Population Medicine and Diagnostic Sciences and director of the Virology Laboratory at the College of Veterinary Medicine’s (CVM) Animal Health Diagnostic Center. 

Over the course of the pandemic, deer have become infected with SARS-CoV-2 through ongoing contact with humans, possibly from hunting, wildlife rehabilitations, feeding of wild animals or through wastewater or water sources, though no one knows for sure.

Tuesday, January 24, 2023

Parasite common in cats causes abortion in bighorn sheep

Bighorn sheep
Photo Credit: David Mark

A parasite believed to be present in more than 40 million people in the United States and often spread by domestic and wild cats could hamper ongoing conservation efforts in bighorn sheep.

A recent study led by Washington State University researchers at the Washington Animal Disease Diagnostic Laboratory found that Toxoplasma gondii, a parasite that infects most species of warm-blooded animals and causes the disease toxoplasmosis, is a cause of abortions, or pregnancy loss, as well as neonatal deaths in the sheep. Researchers documented five cases in bighorn sheep in a study published in the Journal of Wildlife Diseases, but additional studies are needed to determine the full scope of its impact, the authors said.

“We have seen Toxoplasma as a cause of fetal and neonate loss pretty commonly in domestic sheep, but we hadn’t seen pregnancy loss due to toxoplasmosis yet in bighorn sheep,” said Elis Fisk, the lead author of the study. “Unfortunately, it does appear to be causing abortions and some level of death in young bighorn lambs.”

Wednesday, January 4, 2023

Major Breakthrough as Scientists Sequence the Genomes of Endangered Sharks

Hammerhead Shark
Photo Credit: David Clode

The first-ever chromosome-level genome sequences completed for great hammerhead and shortfin mako sharks have shown that both species have experienced major population declines over a 250,000-year history. Low genetic diversity and signs of inbreeding add a layer of concern to the management of Critically Endangered great hammerhead sharks, whose populations have been in freefall recently due to overfishing for their highly valued fins. In contrast, with a larger effective population size (the ideal breeding population size) in the past and higher genetic diversity, shortfin mako sharks appear equipped to be more resilient to rapid environmental change: that is, if the current fishing pressure on them is substantially reduced.

“With their whole genomes deciphered at high resolution we have a much better window into the evolutionary history of these endangered species,” said Mahmood Shivji, Ph.D., professor at Nova Southeastern University’s (NSU) Halmos College of Arts and Sciences and director of the Save Our Seas Foundation Shark Research Center and NSU’s Guy Harvey Research Institute.

It’s a startling image that describes a milestone in conservation science for sharks. Shivji, Michael Stanhope, Ph.D., from Cornell University’s College of Veterinary Medicine and their collaborators have glanced back in history by sequencing to chromosome level the genomes (entire genetic blueprint) of great hammerhead and shortfin mako sharks. Their DNA timeline shows that their populations have declined substantially over 250,000 years. What the scientists have also found is worrying: great hammerhead sharks have low genetic variation, which makes them less resilient to adapting to our rapidly changing world. The species also shows signs of inbreeding, an issue that can lower the ability of its populations to survive.

Thursday, December 15, 2022

Artificial Intelligence in Veterinary Medicine Raises Ethical Challenges

Chimmi (Chimichanga) a few hours before having his spleen removed due to a mass. Detected by Hi-Def Ultrasound by a radiologist. 7/2021
Photo Credit: Heidi-Ann Fourkiller

Use of artificial intelligence (AI) is increasing in the field of veterinary medicine, but veterinary experts caution that the rush to embrace the technology raises some ethical considerations.

“A major difference between veterinary and human medicine is that veterinarians have the ability to euthanize patients – which could be for a variety of medical and financial reasons – so the stakes of diagnoses provided by AI algorithms are very high,” says Eli Cohen, associate clinical professor of radiology at NC State’s College of Veterinary Medicine. “Human AI products have to be validated prior to coming to market, but currently there is no regulatory oversight for veterinary AI products.”

In a review for Veterinary Radiology and Ultrasound, Cohen discusses the ethical and legal questions raised by veterinary AI products currently in use. He also highlights key differences between veterinary AI and AI used by human medical doctors.

Wednesday, November 30, 2022

Important discovery could help extinguish disease threat to koalas

Retrovirus is more prevalent in New South Wales and Queensland koalas, compared to animals in Victoria and South Australia.
Photo Credit: Jordan Whitt

University of Queensland virologists are a step closer to understanding a mysterious AIDS-like virus that is impacting koala populations differently across state lines.

Dr Michaela Blyton and Associate Professor Keith Chappell from the Australian Institute for Bioengineering and Nanotechnology (AIBN) and School of Chemistry and Molecular Biosciences, have uncovered another piece of the puzzle in their quest to halt the koala retrovirus known as KoRV - a condition strongly associated with diseases that cause infertility and blindness.

“We’ve learned that the retrovirus is far more prevalent in New South Wales and Queensland koalas, compared to the southern populations in Victoria and South Australia,” Dr Blyton said.

“Uncovering crucial patterns like these helps us learn how the disease is evolving, how it’s spreading, and how we can contain the damage through anti-viral medication or koala breeding programs.”

Koala numbers have fallen rapidly over the past decade due to widespread land clearing, climate change induced weather events, and disease.

Dr Blyton’s research has already established the link between KoRV and chlamydia, cystitis and conjunctivitis, which suggests the virus weakens the animal’s immune system.

Tuesday, November 29, 2022

Common Veterinary Drugs Show Effectiveness Against Bed Bugs

Fluralaner and ivermectin were tested for their effectiveness in killing bed bugs.
Photo Credit: Courtesy of Coby Schal and Maria Gonzalez-Morales.

Two common drugs used by veterinarians to combat parasites may be effective against bed bugs, with one showing especially strong potential, according to a new study from North Carolina State University that examined the drugs in the context of controlling resurgent bed bug populations on poultry farms.

Fluralaner and ivermectin, which are used to kill fleas and ticks on household pets like dogs and cats, among other uses, were tested for their effectiveness in killing bed bugs. In a collaboration between entomologists and veterinary scientists from NC State’s College of Veterinary Medicine, researchers tested bed bug mortality rates in different experiments: after the pests consumed blood mixed with the drugs on the lab bench and after bed bugs bit and fed off chickens that had either ingested or received topical treatment with the drugs.

Fluralaner is a relatively new, longer-lasting anti-parasitic drug used mostly for companion animals; however, Europe and Australia have approved its use for the poultry industry. Besides household pet uses, ivermectin effectively serves anti-parasitic uses in human populations, particularly in Africa, as well as in larger animals.

Monday, November 28, 2022

Why steamed hay can lead to protein deficiency in horses

Photo Credit: Manfred Richter

Hay treated with hot steam is safer for horses but provides them with less protein. The horse forage is treated with steam to rid it of potentially harmful microorganisms and to bind particles that could otherwise be inhaled. However, a team of scientists from Martin Luther University Halle-Wittenberg (MLU) has discovered that this also causes a chemical reaction which damages the proteins in the hay and makes them harder for horses to digest. This can lead to signs of nutrient deficiency in the animals and, for example, impair growth or muscle development. The team reports on their scientific work in the journal Animals.

Hot steam is used to heat hay up to 100 degrees Celsius, which kills harmful microorganisms and binds fungal spores and dust to the hay. "Many horses suffer from lung problems such as equine asthma. The steaming process virtually eliminates all of the living microorganisms and particles in the hay that could be inhaled during feeding and damage the lungs. In theory, the end result is a very good forage," explains Professor Annette Zeyner from the Institute of Agricultural and Nutritional Sciences at MLU.

Saturday, November 5, 2022

Limiting antibiotics for cows may create a new dairy market

Photo Credit: David Mark

Consumers would be willing to buy milk from cows only treated with antibiotics when medically necessary – as long as the price isn’t much higher than conventional milk, according to researchers at the College of Veterinary Medicine.

The findings suggest conventional farmers could tap a potentially large market for this type of milk if they can find the right price point – and that dairy consumers can help slow the rise of antimicrobial resistance.

“Most of the antibiotics produced throughout the world are used for animal agriculture. Therefore, reducing antibiotic use in animals, including dairy cattle, is necessary to tackle antibiotic resistance at a global scale,” said Dr. Renata Ivanek, professor in the Department of Population Medicine and Diagnostic Sciences. She is senior author on the study, which was published Nov. 4 in the Journal of Dairy Science.

In the paper, the researchers propose a new label for milk that indicates responsible antibiotic use (RAU), which would leverage consumer preferences to reduce the use of antibiotics on commercial dairy farms. The study showed that, although a consumer’s willingness to pay for the RAU-labeled milk was comparable to how much they would pay for the unlabeled milk, they strongly preferred the RAU-labeled milk over the unlabeled milk option. Therefore, the researchers hypothesize this new RAU label would entice farmers to minimize antibiotics more than they do for conventional, unlabeled milk.

Monday, October 31, 2022

Just like humans, more intelligent jays have greater self-control

A study has found that Eurasian jays can pass a version of the ‘marshmallow test’ – and those with the greatest self-control also score the highest on intelligence tests.
Photo Credit: Takashi Yanagisawa

This is the first evidence of a link between self-control and intelligence in birds.

Self-control - the ability to resist temptation in favor of a better but delayed reward – is a vital skill that underpins effective decision-making and future planning.

Jays are members of the corvid family, often nicknamed the ‘feathered apes’ because they rival non-human primates in their cognitive abilities. Corvids hide, or ‘cache’, their food to save it for later. In other words, they need to delay immediate gratification to plan for future meals. The researchers think this may have driven the evolution of self-control in these birds.

Self-control has been previously shown to be linked to intelligence in humans, chimpanzees and – in an earlier study by these researchers – in cuttlefish. The greater the intelligence, the greater the self-control.

The new results show that the link between intelligence and self-control exists across distantly related animal groups, suggesting it has evolved independently several times.

Of all the corvids, jays in particular are vulnerable to having their caches stolen by other birds. Self-control also enables them to wait for the right moment to hide their food without being seen or heard.

Tuesday, October 18, 2022

Reliably estimating proportion of vaccinated populations in wildlife

Japanese Wild Boar
Credit: KENPEI, CC BY-SA 3.0/Wikimedia Commons

Researchers develop a ground-breaking model to estimate bait vaccination effectiveness in wild animals based on the proportion of immunized animals in a population and the number of vaccine applications.

Wild animals are host to pathogens that cause a wide variety of infectious diseases, including zoonotic diseases such as rabies, influenza and tuberculosis. The control of these diseases in wild animals is an important issue in the fields of public health, livestock health, and conservation biology. One of the most widely used methods of control is vaccination of wildlife via bait containing oral vaccines (bait vaccination). However, assessing the effectiveness of these vaccines has been difficult.

A team of scientists led by Associate Professor Ryosuke Omori at the International Institute for Zoonoses Control, Hokkaido University, has developed a ground-breaking model to estimate the effectiveness of bait vaccination in wild animals. Their model and findings were published in the journal PLOS Computational Biology.

Wednesday, September 28, 2022

Birth of a sibling triggers long-lasting stress in young bonobos

Young bonobos as old as eight years suffer long-lasting stress after the birth of a sibling. 
Credit: MPI of Animal Behavior/ Christian Ziegler

In any family, the birth of a child is a transformative event, often greeted with positive feelings from parents—and mixed feelings from siblings. The arrival of a new brother or sister, and the loss of parental attention that comes with it, is stressful for any first-born child. Now, scientists have shown that it is not just humans who have trouble becoming siblings. Bonobos, our closest living relatives, also experience stress in the transition to siblinghood. Following the birth of a sibling, young bonobos had five times higher levels of the stress hormone cortisol and a reduced immune response, which lingered for months. The international team of researchers behind the study were able to show that the stress response was due to the birth of siblings, and not to the natural weaning process that young bonobos inevitably go through. The study on wild bonobos, which is the first to investigate physiological changes in an animal as it transitions to siblinghood, reveals similarities between humans and bonobos—and an evolutionary history behind the stressful event of becoming a sibling.

Bonobos (Pan paniscus) are a species of great ape found only in the Congolese rainforest. Like humans, bonobos and other great apes take an unusually long time to reach independence. Bonobos rely on their mothers for food and protection for eight years and only reach full adulthood at 12 years. While in most animals, offspring are weaned before the mother gives birth to another infant. In bonobos, maturation is slow and the birth of another baby happens long before the older infant has become independent—setting the scene for sibling rivalry.

Wednesday, September 21, 2022

No evidence that dehorning black rhinos negatively impacts the species’ reproduction or survival

A sedated black rhino in the process of being dehorned, with a cap over its eye to protect it from the dust
Credit: Piet Beytell, Namibian Ministry of Environment, Forestry and Tourism

There are no statistically significant differences in key factors of population growth - breeding, birth, survival, life span and death - between dehorned or horned black rhinos new research, conducted by the University of Bristol Vet School, Namibian Ministry of Environment, Forestry and Tourism, and Save the Rhino Trust has found.

The black rhino is critically endangered, with poaching one of several threats to the species’ survival. Many reserves across a number of African countries, including Namibia, South Africa, and Zimbabwe, now dehorn their rhinos in an attempt to reduce poaching but few studies have looked at the impacts of dehorning, particularly in black rhinos.

The study aimed to build on existing knowledge of population productivity between dehorned and horned individuals in four sub-populations of black rhino (of the sub-species Diceros bicornis bicornis) in Namibia.

Three of the populations had undergone some level of dehorning at least once while one of the populations had never been dehorned. The measures investigated included: age of females at the birth of their first calf (age at first reproduction or AFR); average time between the birth of calves for each female (inter-calving interval); birth sex ratios, calf survival, life span and cause of death

Wednesday, September 14, 2022

Vets and pets to reap benefits from new drug to treat common infection


Australia’s 29 million pets look set to benefit from a more effective treatment for Giardia, a common intestinal infection in dogs and cats, thanks to a collaboration between academia and industry.

Pharmaceutical scientists from five Australian universities are partnering with veterinary pharmaceutical company Neoculi Pty Ltd to develop a new drug to treat Giardia, which affects at least 15 per cent of dogs, particularly puppies, and approximately 12 per cent of cats.

Existing treatments on the market are ineffective and have significant drawbacks, according to University of South Australia pharmaceutical scientist Professor Sanjay Garg, one of the key collaborators on the three-year project, led by the University of Newcastle.

Professor Garg says current drugs have limited effectiveness due to parasitic resistance, require multiple treatments and have toxic side effects.

“The drug we are developing is safe and effective in one single dose. We are aiming to produce a palatable formulation that pets will take without any resistance.” Prof Garg says. “It should be available within three years.”

Tuesday, September 6, 2022

Endangered Amargosa Voles Begin to Repopulate Desert Habitat

This landscape shows the Amargosa Valley at sunset. Amargosa voles are endemic to unique Mojave Desert marshes fed by natural springs and the Amargosa River.
Credit: University of California, Davis

Seven years of carefully planned habitat restoration on private land in the Mojave Desert have yielded hope for the persistence of the endangered Amargosa vole. In early August, a photograph from a wildlife camera placed by researchers from the University of California, Davis, and dated July 3 revealed the presence of one, possibly two, vole pups born from parents that were reintroduced to restored marsh habitat on private land in Shoshone Village, Inyo County.

The Amargosa vole was first discovered in the marshes of Shoshone in the late 1800s but had disappeared by the early 1900s because of habitat conversion to agriculture and other uses that destroyed the marshes. The only other place in the world where the voles persist in the wild is near the town of Tecopa, about 8 miles south of Shoshone.

Restoration of the Shoshone Spring marsh started in 2015 as a joint effort of Shoshone Village, the Amargosa Conservancy, UC Davis and the California Department of Fish and Wildlife (CDFW). The restoration was funded by U.S. Fish and Wildlife Service (USFWS) Section 6 and Partners in Fish and Wildlife grants.

Wednesday, August 17, 2022

Scientists Create a DNA Test That Identifies Lyme Disease in Horses

Photo credit: Christine Mendoza on Unsplash

A Rutgers scientist aiming to help heal a sick horse created an ultra-sensitive DNA test that could have applications for difficult-to-detect illnesses in humans such as Lyme disease.

As described in a study published in the Journal of Veterinary Diagnostic Investigation, a special DNA test devised by Steven Schutzer, a professor of medicine at Rutgers New Jersey Medical School, helped a Cornell University School of Veterinary Medicine team identify Neurologic Lyme disease in a sick 11-year-old Swedish Warmblood mare.

Although Lyme disease was suspected, a standard PCR test didn’t detect the disease agent, the corkscrew-shaped bacterium Borrelia burgdorferi.

As with the treatment of most diseases, early detection is essential with Lyme.

“Early diagnosis leads to immediate treatment,” Schutzer said. “And, naturally, that gives the best chance for a cure.”

The Schutzer team’s “genomic hybrid capture assay,” a highly sensitive test the team has been developing, identified the pathogen in a sample of the horse’s spinal fluid, allowing it to be diagnosed and successfully treated. The test works by first selectively isolating DNA from the microorganism causing the disease.

“The method is like having a special, specific ‘fishhook’ that only grabs Borrelia DNA and not the DNA of other microbes, nor the DNA of the host (animal or human),” Schutzer said. “Detecting DNA of the disease is a direct test, meaning we know you have active disease if it’s circulating in the blood or spinal fluid.”

Thursday, August 11, 2022

Mini donkey gets big boost from pacemaker

Veterinarians at Cornell prepare miniature donkey Nix for her pacemaker surgery.
Credit: Carol Jennings/CVM 

Nix, a miniature donkey with a potentially fatal heart condition, is on the mend after a successful pacemaker implantation by veterinarians at the Cornell University Hospital for Animals – the first surgery of its kind in a large animal species at Cornell.

“It was either do nothing and Nix would continue to get worse and possibly have a painful death – or the pacemaker,” said Mindy Lockwood of Canandaigua, New York, who owns Nix with her husband, Carlton.

Nix’s collapsing episodes and overall lethargy began in the fall of 2020 when she was only a few months old. Her regular veterinarian, Dr. Joan Ayers of Genesee Valley Veterinary Hospital, assessed her condition in consultation with the Lockwoods and Dr. Barbara Delvescovo, clinical fellow in the Section of Large Animal Medicine at Cornell.

In February of this year, Nix’s condition worsened. The Lockwoods saw that Nix was falling again, this time from a standing position, and she staggered even more while walking. “When she fell, she was dazed for a few seconds and then would get back up. Several times she fell and rolled out of the pasture fence, which caused us even more concern for her safety,” Carlton Lockwood said.

Tuesday, August 9, 2022

Hearing Loss in Dogs Associated With Dementia

Image by Chen Vision, licensed under CC BY-NC 2.0

A new study from North Carolina State University explores the connection between hearing loss and dementia in geriatric dogs. The work could aid in both treatment of aging dogs and in understanding the relationship between sensory loss and cognitive function in dogs.

“In humans, we know that age-related hearing loss is estimated to affect one-third of people over age 65,” says Natasha Olby, the Dr. Kady M. Gjessing and Rahna M. Davidson Distinguished Chair in Gerontology at North Carolina State University and corresponding author of the study.

“We also know that the rate of cognitive decline is approximately 30-40% faster in people with age-related hearing loss and that hearing loss is a greater contributor to dementia risk than other factors such as hypertension or obesity. But we don’t understand whether the same holds true for dogs.”

In the study, Olby and colleagues evaluated 39 senior or geriatric dogs. Auditory and cognitive tests were performed on each dog and their owners were asked to fill out two commonly used questionnaires – one focused on cognitive ability and the other on quality of life. Cognitive testing, questionnaire scores and age were compared between hearing groups.

Monday, July 4, 2022

Male dogs four times more likely to develop contagious cancer on nose or mouth than females


A new study has found that male dogs are four to five times more likely than female dogs to be infected with the oro-nasal form of Canine Transmissible Venereal Tumor.

Researchers think this is because of behavior differences between the sexes: male dogs spend more time sniffing and licking female dogs’ genitalia than vice versa.

Canine Transmissible Venereal Tumor, or CTVT, is an unusual cancer – it is infectious and can spread between dogs when they come into contact. The living cancer cells physically ‘transplant’ themselves from one animal to the other.

CTVT commonly affects dogs’ genitals and is usually transmitted during mating. But sometimes the cancer can affect other areas like the nose, mouth and skin.

In the study, the researchers reviewed a database of almost 2,000 cases of CTVT from around the globe and found that only 32 CTVT tumors affected the nose or mouth. Of these, 27 cases were in male dogs.

“We found that a very significant proportion of the nose or mouth tumors of canine transmissible cancer were in male dogs,” said Dr Andrea Strakova in the University of Cambridge’s Department of Veterinary Medicine, first author of the paper. She performed this study with colleagues from the Transmissible Cancer Group, led by Professor Elizabeth Murchison.

Strakova added: “We think this is because male dogs may have a preference for sniffing or licking the female genitalia, compared to vice versa. The female genital tumors may also be more accessible for sniffing and licking, compared to the male genital tumors.”

Tuesday, June 28, 2022

Highly antibiotic-resistant strain of MRSA that arose in pigs can jump to humans

Pig farm 
Credit: Mark Holmes

The strain, called CC398, has become the dominant type of MRSA in European livestock in the past fifty years. It is also a growing cause of human MRSA infections.

The study found that CC398 has maintained its antibiotic resistance over decades in pigs and other livestock. And it is capable of rapidly adapting to human hosts while maintaining this antibiotic resistance.

The results highlight the potential threat that this strain of MRSA poses to public health. It has been associated with increasing numbers of human infections, in people who have and have not had direct contact with livestock.

“Historically high levels of antibiotic use may have led to the evolution of this highly antibiotic resistant strain of MRSA on pig farms,” said Dr Gemma Murray, a lead author of the study, previously in the University of Cambridge’s Department of Veterinary Medicine and now at the Wellcome Sanger Institute.

She added: “We found that the antibiotic resistance in this livestock-associated MRSA is extremely stable – it has persisted over several decades, and also as the bacteria has spread across different livestock species.”

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