college of veterinary medicine

OSU study finds selenium added to alfalfa boosts calf growth, immunity

CORVALLIS, Ore. – A new study by Oregon State University researchers has found that adding selenium to fields planted with alfalfa will allow the perennial forage crop to “take up” the important mineral in its tissues, providing better feed for calves and other livestock.

The findings are particularly important, researchers say, because selenium delivered through plants in an organic form is much safer than directly feeding selenium to calves in an inorganic form, such as salt.

Results of the study have been published in part in the journal PLOS One.

Selenium is a naturally occurring mineral that is found in heavy concentrations in some parts of the country, and at low levels in others – including Oregon. Ranchers often provide selenium in supplements to livestock, but applications must be done carefully because too much of the mineral can be harmful to animals.

Providing the mineral in organic form greatly lessens the threat of toxicity, according to Jean Hall, a professor in the College of Veterinary Medicine at OSU and lead author on the PLOS One article.

“When selenium gets picked up by the plant, it goes right into the amino acid selenomethionine, and when the animals consume it, the selenium gets stored in the muscle in a benign way,” Hall said. “The ranchers we’ve spoken with are extremely interested in these results, because not only does it appear this is safer for the animals, it may be cost-effective as well.”

During field trials, selenium was applied at varying levels to alfalfa hay fields after the first of three scheduled cuttings. Regardless of the level of selenium applied, the plants had taken up 83 percent of the selenium by the time of the second cutting. The remaining 17 percent of the applied selenium was taken up in the alfalfa by the third cutting.

The percentage of selenium uptake by the alfalfa was consistent regardless of the amount applied, according to Hall. “If we doubled the amount of selenium, the plants took up twice as much,” she said.

The researchers then fed selenium-fortified alfalfa to calves and compared their growth to control animals. Several weeks later, the calves with supplemented diets had higher blood selenium content levels at a rate commensurate with the amount of selenium applied to the fields. The calves fed selenium-fortified alfalfa also weighed up to 10 percent more than calves fed alfalfa without selenium.

Weight growth by the calves increased with additional selenium, Hall said, though there was more variability than the linear response by the plants.

“We also tested weaned calves to see if selenium-fortified alfalfa might boost the efficacy of vaccinations, giving a boost to the animals’ immune system,” Hall said, “and it appears that is the case. Calves fed the selenium-fortified alfalfa had increased antibody production – at a rate that mirrors the amount of selenium applied.

“The study demonstrates that selenium-fortified hay boosts the growth and vaccination response of weaned beef calves, which results in decreased mortality and improved slaughter weights,” she added.

Hall is a fifth-generation Oregonian who comes from a cattle ranching family in Douglas County. She is part of a long history of selenium studies at OSU that go back 50 years.

“Oregon is the only state where you can artificially fertilize fields with selenium,” Hall said, “and because most areas of the state are deficient in the mineral, this may be a strategy to consider for ranchers. Some countries, including Denmark and Finland, require fertilization in fields to increase the amount of selenium in the food chain, so the precedent is there.”

Other authors on the paper, all from OSU, include Gerd Bobe, Janice Hunter, William Vorachek, Whitney Stewart, Jorge Vanegas, Charles Estill, Wayne Mosher and Gene Pirelli.

Media Contact: 

Jean Hall, 541-737-6532; jean.hall@oregonstate.edu

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Oregon cattle
Selenium added to
alfalfa fields boost
nutrition in cattle.

Assay developed to rapidly detect disease that hurt oyster industry

The study this story is based on is available in ScholarsArchive@OSU: http://bit.ly/11nabvq


CORVALLIS, Ore. – Scientists in the College of Veterinary Medicine at Oregon State University have developed a new, inexpensive and precise way to detect the toxin secreted by Vibrio tubiashii, a bacterial disease that a few years ago caused millions of dollars in losses to the oyster aquaculture industry in the Pacific Northwest.

When perfected and commercialized, the new assay should give oyster growers an early warning system to tell when they have a problem with high levels of this toxin and must take quick steps to address it. Findings were just published in the Journal of Microbiological Methods.

V. tubiashii has caused major problems for oyster growers in recent years, especially in 2007 when a major outbreak almost crippled the industry. When the bacteria and the toxin it produces reach unacceptably high levels, they can kill the tiny seed oysters before they have a chance to grow.

“We still need to improve the sensitivity of the test and better quantify results, but it should provide information in about 30 minutes that used to take three or four days,” said Frances Biel, a faculty research assistant in the OSU Department of Biomedical Sciences. “That type of rapid detection will let oyster growers know they have a problem while they can still do something about it.”

The oyster die-offs that began happening in the late 2000s appear to have various causes, researchers say, including changes in ocean acidification. Some measures were taken to help deal with the acidification, but widespread die-offs continued to occur that couldn’t be linked to that problem. The vibriosis disease caused by this bacteria was found to be a major concern. The largest shellfish hatchery on the West Coast, in Oregon’s Netarts Bay, faced near closure as a result of this crisis.

“Shockingly little was known about V. tubiashii at first, and the toxins that it produces,” said Claudia Hase, an OSU associate professor of veterinary medicine. “It secretes a zinc-metalloprotease compound that’s toxic to shellfish, and that’s what our new assay is able to detect.”

Besides oysters, this bacteria and toxin can also affect shrimp, clams and other marine species important to aquaculture.

The new assay uses a “dipstick” that has proven superior to another approach which was tested, and conceptually it’s similar to a human pregnancy test. It uses monoclonal antibodies that recognize the particular toxic protein of concern.

Marine food farming around the world depends on hatchery and nursery production of large quantities of high quality, disease-free larvae, experts said. Vibriosis in various species has been linked to major problems around the world since the late 1970s. This and other research at OSU has made significant progress in understanding the pathogenicity and toxicity of V. tubiashii.

Aside from farmed oysters and other seafood, there have also been declines of wild shellfish in some locations in recent years on the West Coast. It’s likely that increasing levels of vibriosis are related to that, researchers said. Declining coral reefs also suffer from a closely related bacterial species.

This research was supported by the U.S. Department of Agriculture and the National Oceanic and Atmospheric Administration.

Media Contact: 

Claudia Hase, 541-737-7001

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Oyster larvae

Oyster larvae

College of Veterinary Medicine

About the OSU College of Veterinary Medicine: The primary mission of the OSU College of Veterinary Medicine is to serve the people of Oregon and the various livestock and companion animal industries by furthering the understanding of animal medical practices and procedures. Through research, clinical practice and extension efforts in the community, the college provides Oregon's future veterinarians with one of the most comprehensive educations available anywhere.

OSU lifts quarantine for equine influenza, cites swift biosecurity as key to halt outbreak

CORVALLIS, Ore. – A horse treated for equine influenza at Oregon State University’s College of Veterinary Medicine earlier this month has fully recovered, and the large animal hospital there is once again accepting equine patients.

The horse, which recently arrived in Oregon from Texas, was quarantined at the hospital for 10 days.

“We chose to temporarily close the hospital to equine patients with non-emergency symptoms for a week as an added precaution because equine influenza can spread rapidly among horses and other equines,” said Keith Poulsen, an internal medicine specialist at the Lois Bate Acheson Veterinary Hospital. “Everything is back to normal now, and the horse has returned to its home in eastern Oregon.”

Equine influenza is the most common contagious respiratory pathogen for horses, though it is not transferable to humans or other animal species. Most animals that contact the disease fully recover.

The Large Animal Internal Medicine and Surgery Services program at OSU’s College of Veterinary Medicine worked closely with the state veterinarian’s office to inform veterinarians and horse owners about the disease. Several horses from the sale in Hermiston, Ore., contracted respiratory disease consistent with equine influenza, Poulsen said, but no hospitalized horses at the OSU Veterinary Hospital developed respiratory disease.

Poulsen and his colleagues suggest that horse owners use caution when traveling with their horses and to contact their veterinarian or the OSU College of Veterinary Medicine with questions about equine influenza or any infectious disease.

Media Contact: 

Keith Poulsen, 541-737-2858

OSU treats horse for equine influenza; warns horse owners to be vigilant

CORVALLIS, Ore. – A horse from Eastern Oregon that was referred to Oregon State University’s veterinary teaching hospital because of illness has been diagnosed with equine influenza virus, a highly contagious respiratory disease in horses that typically is not fatal.

The four-year-old quarter horse mare, which recently arrived in Oregon from Texas, has been placed in isolation and is being treated.

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

“Equine influenza is especially dangerous to foals and the foaling season just started,” said Keith Poulsen, an internal medicine specialist at the Lois Bate Acheson Veterinary Hospital in OSU’s College of Veterinary Medicine. “The virus can be spread by direct contact with nasal discharge, or when aerosolized from coughing.”

The Large Animal Internal Medicine and Surgery Services program at OSU’s College of Veterinary Medicine is working with the state veterinarian’s office to inform veterinarians and horse owners about the disease.

Poulsen said the first clinical sign in horses is typically a fever, followed by cough, nasal discharge and lethargy. Horses with a fever of greater than 102.5 degrees should be seen by a veterinarian. Horse owners should also consult with their veterinarian about vaccinations, he added.

Infected horses can “shed” or transmit the virus for up to 10 days after incubation. Horses that show signs of the disease should be isolated from other horses for 10 days after clinical signs first appear.

“The good news is that many disinfectants can easily kill the equine influenza virus, and thoroughly cleaning stalls and equipment can help prevent the virus from spreading,” Poulsen said.

The Eastern Oregon horse was purchased at a sale in Hermiston last weekend and several horses that were in close contact with it also have developed signs of illness, though they have not yet been diagnosed with equine influenza virus, officials say.

The horse will remain at OSU in isolation until it fully recovers. As an added precaution, the OSU hospital is only accepting equine patients requiring emergency treatment until Wednesday, Feb. 27. Horses being referred for elective surgery, lameness or non-emergency conditions will be delayed until after Wednesday.

“The college has some of the most sophisticated isolation facilities of any facility in the country,” noted Helio de Morais, interim director of the Lois Bates Acheson Veterinary Hospital. “Safely treating animals such as these – and working with veterinarians and animal owners around the state to prevent the spread of these diseases – is what we do best.”

Media Contact: 

Keith Poulsen, 541-737-4812

Ornamental fish industry faces problems with antibiotic resistance

NEWPORT, Ore. – The $15 billion ornamental fish industry faces a global problem with antibiotic resistance, a new study concludes, raising concern that treatments for fish diseases may not work when needed – and creating yet another mechanism for exposing humans to antibiotic-resistant bacteria.

The risk to humans is probably minor unless they frequently work with fish or have compromised immune systems, researchers said, although transmission of disease from tropical fish has been shown to occur. More serious is the risk to this industry, which has grown significantly in recent years, and is now a $900 million annual business in the United States.

There are few regulations in the U.S. or elsewhere about treating ornamental fish with antibiotics, experts say. Antibiotics are used routinely, such as when fish are facing stress due to transport, whether or not they have shown any sign of disease.

“We expected to find some antibiotic resistance, but it was surprising to find such high levels, including resistance in some cases where the antibiotic is rarely used,” said Tim Miller-Morgan, a veterinary aquatics specialist with Oregon State University. “We appear to already have set ourselves up for some pretty serious problems within the industry.”

In the new study, 32 freshwater fish of various species were tested for resistance to nine different antibiotics, and some resistance was found to every antibiotic. The highest level of resistance, 77 percent, was found with the common antibiotic tetracycline. The fish were tested in Portland, Ore., after being transported from Colombia, Singapore and Florida.

Findings of the study were reported in the Journal of Fish Diseases.

The bacterial infections found in the fish included Aeromonas, Pseudomonas, Staphylococcus and others, several of which can infect both fish and humans.

“The range of resistance is often quite disturbing,” the scientists wrote in their report. “It is not uncommon to see resistance to a wide range of antibiotic classes, including beta-lactams, macrolides, tetracyclines, sulphonamides, quinolones, cephalosporins and chloramphenicol.”

Problems and concerns with antibiotic resistance have been growing for years, Miller-Morgan said. The nature of the resistance can range widely, causing an antibiotic to lose some, or all of its effectiveness.

There have been documented cases of disease transmission from fish to humans, he said, but it’s not common. It would be a particular concern for anyone with a weak or compromised immune system, he pointed out, and people with such health issues should discuss tropical fish management with their physician. Workers who constantly handle tropical fish may also face a higher level of risk.

From an industry perspective, losses of fish to bacterial disease may become increasingly severe, he said, because antibiotics will lose their effectiveness.

Anyone handling tropical fish can use some basic precautions that should help, Miller-Morgan said. Consumers should buy only healthy fish; avoid cleaning tanks with open cuts or sores on their hands; use gloves; immediately remove sick fish from tanks; consider quarantining all new fish in a separate tank for 30 days; wash hands after working with fish; and never use antibiotics in a fish tank unless actually treating a known fish disease caused by bacteria.

“We don’t think individuals should ever use antibiotics in a random, preventive or prophylactic method,” Miller-Morgan said. “Even hobbyists can learn more about how to identify tropical fish parasites and diseases, and use antibiotics only if a bacterial disease is diagnosed.”

On an industry level, he said, considerable progress could be made with improvements in fish husbandry, better screening and handling, and use of quarantines, rather than antibiotics, to reduce fish disease.

The ornamental fish industry is large and diverse, including trade of more than 6,000 species of freshwater and marine fish from more than 100 different countries. About half the supply originates in Asia, and freshwater farming of ornamental fish is a rapidly growing industry.

Also increasing is the number of trained fish veterinarians, who can help fish hobbyists to reduce disease loss and save treasured pets. More information is available from the World Aquatic Veterinary Medical Association and the American Association of Fish Veterinarians. A database of aquatic veterinarians is available online, at http://aquavetmed.info

Media Contact: 

Tim Miller-Morgan, 541-867-0265

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Ornamental fish

Ornamental fish

Can you really give your dog or cat the flu?

CORVALLIS, Ore. – 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.

Media Contact: 

Christiane Loehr, 541-737-9673

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Risk to pets

Risk to pets

West Nile virus activity on the increase in Oregon

CORVALLIS, Ore. – Although summer may be winding down, the threat of West Nile virus in Oregon appears to be increasing, putting humans and some animals at risk.

The Oregon Health Authority has confirmed two human cases of West Nile virus in Oregon this week. And the Veterinary Diagnostic Laboratory at Oregon State University, which provides testing for the state, is reporting the highest levels of West Nile virus activity in mosquitoes since 2009. The lab has confirmed the virus in 58 different “pools” of mosquitoes – of which 55 were located in Malheur County.

In contrast, only three pools of West Nile virus were confirmed last year in Oregon, and four in 2010.

“It is still far less than in past years, such as 2006, when we confirmed the virus in some 1,100 pools of mosquitoes,” said Donna Mulrooney, supervisor of the molecular diagnostics section of OSU’s Veterinary Diagnostic Laboratory. “However, activity has been increasing over the past couple of weeks and it’s possible that it could continue moving west across the state.”

The virology section of the diagnostic lab has also confirmed West Nile virus in one horse in Klamath County, and in a crow from Malheur County. Certain birds are known carriers of West Nile virus, Mulrooney said.

“Infected crows, ravens, jays and other members of the corvid family are considered ‘reservoirs’ and will carry very high viral loads of West Nile,” she pointed out. “If they are bitten by mosquitoes, those mosquitoes invariably will become infected with the virus.

“Horses, on the other hand, are known as ‘dead-end’ hosts,” Mulrooney added. “They don’t carry enough of a viral load to infect mosquitoes if bitten. However, the danger to horses is real. Anywhere from 30 to 50 percent of horses infected with West Nile virus will die.”

In Oregon, West Nile virus surveillance efforts are coordinated and funded by the Oregon Health Authority, with testing of animals and mosquitoes performed at the Veterinary Diagnostic Lab in OSU’s College of Veterinary Medicine. Emilio DeBess, Oregon Health Authority veterinarian, said West Nile virus typically peaks around Labor Day Weekend. He recommends the following precautions for Oregonians:

  • Eliminate sources of standing water that are a breeding ground for mosquitoes, including watering troughs, bird baths, clogged gutters and old tires;
  • Protect yourself when outside, especially at dusk or dawn when mosquitoes are most active, by using repellants containing DEET, oil of lemon eucalyptus or Picardin, and follow directions;
  • Wear long-sleeved shirts and long pants in mosquito-infested areas;
  • Make sure screen doors and windows fit tightly and are in good repair.

More information on West Nile virus, including symptoms in humans, is available from the Oregon Health Authority at: http://public.health.oregon.gov/DiseasesConditions/DiseasesAZ/WestNileVirus/Pages/survey.aspx

Seventeen Oregon counties maintain mosquito control programs, and many of these vector control agencies conduct preliminary testing for West Nile virus then send the mosquitoes to the OSU Veterinary Diagnostic Laboratory for confirmation. Mulrooney and her colleagues use a polymerase chain reaction test to confirm the virus in mosquitoes, and serology (blood) tests to confirm the disease in horses.

The vector control agencies capture mosquitoes in traps at different strategic locations throughout the county, thus the 50 pools of West Nile virus means infected mosquitoes were found at multiple locations in Malheur County.

“Fifty to 60 pools of West Nile virus isn’t necessarily unusual, but that kind of widespread activity through Malheur County suggests that it might be ready to jump county lines,” said Jerry Heidel, director of the Veterinary Diagnostic Lab.

Media Contact: 

Donna Mulrooney, 541-737-6615

OSU partners with Woodburn School District to increase diversity in medical field

CORVALLIS, Ore. – Oregon State University is hoping to inspire a new generation of students to consider pursuing medical careers by giving high school students from the Woodburn area the chance to spend a week exploring the world of veterinary medicine.

OSU’s College of Veterinary Medicine and the Department of Biomedical Sciences at OSU are partnering with the Woodburn School District to sponsor the Summer Veterinary Experience, which begins Sunday, Aug. 12, and continues through Aug. 17 on the OSU campus.

Veterinary Medicine leaders say the college is committed to increasing the diversity of its student body, which contains 4 percent students of color. By contrast, 86.2 percent of Woodburn School District’s students are classified as minorities. Most of the summer program participants are students of color.

“Woodburn Schools are producing high academic achievers, who are bilingual,” said Susan Tornquist, OSU associate dean for student and academic affairs with the College of Veterinary Medicine. “We hope this partnership will help reach out to students who might not originally think of pursuing a medical degree.”

Ten sophomores and juniors from in and around Woodburn will participate in the program. They will learn about all aspects of the veterinary medicine field, including time in research and anatomy labs and clinical settings. They’ll also have the chance to meet with faculty, and will be assigned a current vet med student as a mentor. They will stay in residence halls on campus and will learn about admission requirements and financial aid opportunities.

“It’s important that students start thinking now about what they need to do in the future to be able to attend college,” said Woodburn School Superintendent David Bautista. 

If successful, the program may be extended to middle school students in the future.


Dr. Susan Tornquist, 541-737-6943

Childhood obesity may affect puberty, create problems with reproduction

CORVALLIS, Ore. – A dramatic increase in childhood obesity in recent decades may have impacts that go beyond the usual health concerns – it could be disrupting the timing of puberty and ultimately lead to a diminished ability to reproduce, especially in females.

A body of research suggests that obesity could be related to growing problems with infertility, scientists said in a recent review, in addition to a host of other physical and psycho-social concerns. The analysis was published in Frontiers in Endocrinology.

Human bodies may be scrambling to adjust to a problem that is fairly new. For thousands of years of evolution, poor nutrition or starvation were a greater concern, rather than an overabundance of food.

“The issue of so many humans being obese is very recent in evolutionary terms, and since nutritional status is important to reproduction, metabolic syndromes caused by obesity may profoundly affect reproductive capacity,” said Patrick Chappell, an assistant professor of veterinary medicine at Oregon State University and an author of the recent report.

“Either extreme of the spectrum, anorexia or obesity, can be associated with reproduction problems,” he said.

Researchers are still learning more about the overall impact of obesity on the beginning of puberty and effects on the liver, pancreas and other endocrine glands, Chappell said. While humans show natural variations in pubertal progression, the signals that control this timing are unclear.

But in general, puberty appears to be starting earlier in girls. It is being accelerated.

This may have several effects, scientists have found. One theory is an impact on kisspeptin, a recently characterized neurohormone necessary for reproduction. Normal secretions of this hormone may be disrupted by endocrine signals from fat that serve to communicate to the brain.

Another possible affect on pubertal timing, and reproduction in general, is disruption of circadian clocks, which reflect the natural rhythms of night and day. Disrupted sleep-wake cycles can affect the secretion of hormones such as cortisol, testosterone, and insulin, researchers have found.

“Any disruption of circadian clocks throughout the body can cause a number of problems, and major changes in diet and metabolism can affect these cellular clocks,” Chappell said. “Disruption of the clock through diet can even feed into a further disruption of normal metabolism, making the damage worse, as well as affecting sleep and reproduction.”

Molecular mechanisms have only started to be uncovered in the past decade, the report said, and the triggers that control pubertal development are still widely debated. For millennia, many mammals made adjustments to reduce fertility during periods of famine. But it now appears that an excess of fat can also be contributing to infertility rates and reproductive diseases.

Some studies in humans have found correlations between early puberty and the risk of reproductive cancers, adult-onset diabetes, and metabolic syndrome. Early onset puberty has also been associated with increased rates of depression and anxiety in girls, studies have found, as well as increased delinquent behavior, smoking and early sexual experiences in both girls and boys.

Other research has suggested that such problems can persist into adulthood, along with lower quality of life, higher rates of eating disorders, lower academic achievement and higher rates of substance abuse.

Additional research is needed to better understand the effect of these processes on metabolism, hormones and other development processes, the survey concluded.

Media Contact: 

Patrick Chappell, 541-737-5361