Researchers at the University of Nottingham say they’ve documented a serious decline in the fertility of male dogs — and suggest that dog food or environmental causes may be to blame.
In a study spanning 26 years, researchers tracked the sperm motility levels of five different breeds — Labrador retrievers, golden retrievers, curly coat retrievers, border collies and German shepherds.
They took samples from between 42 and 97 dogs each year, according to the study, published in Scientific Reports.
Between 1988 and 1998, the team recorded a 2.5 percent decline in the amount of motile sperm per year. Between 2002 and 2014, this trend continued at a rate of 1.2 percent each year.
The researchers also found that male pups produced by dogs with declining sperm quality had an increased incidence of cryptorchidism, a condition where one or both of the testicles don’t descend properly.
The study suggests that the sperm quality may have been impacted by contaminants in dog food.
“We looked at other factors which may also play a part, for example, some genetic conditions do have an impact on fertility,” said Dr Richard Lea, leader of the study. “However, we discounted that because 26 years is simply too rapid a decline to be associated with a genetic problem.”
Dogs used for the study were all bred, raised and trained as service animals for disabled people at an unidentified center in England, according to the New York Times.
The scientists said that in addition to collecting samples throughout the study, they examined the testicles collected from dogs that had undergone castration.
Both showed environmental contaminants in high enough concentrations to affect sperm motility. These same chemicals were also discovered in various commercially available dog foods.
The researchers say the findings raise the question of whether a reported decline in human semen quality over the last 70 years could also be a result of environmental factors.
(Photos: Roscoe, a yellow Lab who was not involved in the study, and has no interest in the results, by John Woestendiek)
Posted by John Woestendiek August 12th, 2016 under Muttsblog.
Tags: animals, breeding, chemicals, contaminants, decline, dog food, dogs, food, health, motility, pets, quality, reproduction, research, semen, sperm, study, testicles, university of nottingham
The university that cloned the first mammal is now investigating why some older dogs — especially those in colder climes — sometimes experience limp tails.
A study at Edinburgh University in Scotland says the phenomenon known as ‘limber tail,’ which causes a dog’s tail to become limp and difficult to move, tends to affect larger working breeds, and is more common among dogs who live in the north.
The study of dozens of dogs found that the chance of a dog developing the condition rose by 50 per cent for each additional degree of latitude further north he or she lived.
Working dogs, who spend more time outdoors, and those who enjoy swimming were also around five times more likely to develop “limber tail,” which is also known as “cold tail” or “swimmer’s tail.” More informally, the condition is sometimes referred to as a dog “losing their wag.”
Personally, we like the name a Telegraph headline writer gave the condition: Erect-tail dysfunction.
No, this is not The Onion you’re reading, and this is not a joke — at least not to the dogs who get it. Owners report that it can be very painful and distressing for the dogs.
“We were surprised by how many owners were reporting limber tail to us but it meant we had the chance to do a detailed investigation,” said Dr. Carys Pugh, of The Roslin Institute and Royal Dick School of Veterinary Studies.
The Royal Dick School of Veterinary Studies, commonly referred to as the Dick Vet, is no joke, either. It’s the veterinary school of the University of Edinburgh.
Dolly the sheep, the world’s first mammal clone, was born at the Roslin Institute in 1996, marking a new era of biological control. Nine years later the cloning of dog — the 18th species successfully cloned — was achieved by scientists in South Korea.
Those affected by limber tail were more likely to be working dogs, and more likely to regularly swim.
The condition, which was first reported in the scientific press in 1997, is thought to affect around 60,000 dogs in Britain, “but owners often struggle to find out what is wrong with their pets as there is little literature available,” the Telegraph reported.
It’s generally not a lifelong condition; rather, it resolves itself within a few days or weeks.
The researchers hope further studies will identify genes associated with the condition, which could one day help breeders to identify animals that are likely to be affected.
Caroline Kisko, Secretary of Kennel Club, which funded the research through its charitable trust, said owners should be careful not to over-expose their dogs to the cold.
“The condition is rare, but is it most often seen in working dogs such as Labrador retrievers, flat coated retrievers and pointers. Dogs usually recover their normal tail posture and function over a period of days or weeks, however it can be painful.”
Gudrun Ravetz, junior vice president of the British Veterinary Association warned owners not to become so worried about the cold that they stop exercising their pets.
“Limber tail is rarely seen in veterinary practices and the research indicates that most owners do not seek veterinary attention for this problem,” she said.
(Photos: Top, a young chocolate Lab with a perky and lively tail; bottom, an older chocolate Lab whose tail has gone limber)
Posted by John Woestendiek August 3rd, 2016 under Muttsblog.
Tags: breeds, cause, cloning, cold, cold tail, edinburgh, erect-tail dysfunction, genes, genetic, limber tail, limp, losing the wag, research, retrievers, roslin institute, science, scientists, study, swimmer's tail, treatment, university of edinburgh, working breeds, working dogs
Specially trained dogs have been alerting diabetics to decreases in their blood sugar levels for years now — but only now do scientists have a pretty good clue of how dogs are able to do it.
Researchers at the University of Cambridge say what the dogs are able to sniff out is a common chemical called isoprene, which is found on our breath.
Isoprene increases significantly — and sometimes almost doubles — during hypoglycemia.
Medical detection dogs wake up or alert their owners whenever their blood sugar level drops to the point of hypoglycemia, a condition that can cause shakiness, loss of consciousness, and, if untreated, death.
Using mass spectrometry, the scientists studied the breath of eight women with type 1 diabetes, noting changes in the chemical signatures of their exhalations when their blood sugar levels were lowered to the point of hypoglycemia.
The increased in isoprene is too subtle for humans to smell, but with the ability to detect odors at concentrations of around one part per trillion, dogs are able to sense it.
The scientists aren’t sure why isoprene increases as blood sugar levels drop, but they suspect it might be a byproduct of cholesterol.
Their findings were published in the July issue of the journal Diabetes Care.
The research could lead the way to developing medical sensors that replicate some of what diabetic alert dogs do, providing diabetics with an alternative to frequent blood testing, said lead researcher, Mark Evans.
“It’s our vision that a new breath test could at least partly – but ideally completely – replace the current finger-prick test, which is inconvenient and painful for patients, and relatively expensive to administer.”
Posted by John Woestendiek July 1st, 2016 under Muttsblog, videos.
Tags: animals, blood sugar, breath, detection, diabetes, diabetic, diabetic alert dogs, dog, dogs, hypoglycemia, increased, isoprene, levels, medical, pets, research, science, scientists, sense, smell, sniff, university of cambridge
Dogs used in scientific research would need to be considered for adoption before they can be routinely euthanized under legislation passed this week in New York.
The measure — focused on beagles because they are most commonly bred for research use — has been sent to Gov. Andrew Cuomo to be signed into law, WGRZ reports.
The Research Animal Retirement Act — also referred to as the “Beagle Freedom Bill” — would require all educational institutions that use dogs or cats in research to establish adoption programs.
The law would mandate that a veterinarian determine whether a beagle or other animal that is no longer useful to researchers is medically suitable for adoption. If approved for adoption, the animal would then be shipped to a shelter or given to an interested owner.
Similar laws have been passed in Nevada, California, Minnesota, and Connecticut.
“This bill, once it is signed into law, will mean that research animals will have a chance at a second life,” said one sponsor of the legislation, Assemblywoman Linda Rosenthal, D-Manhattan.
“All animals, being freed of their testing responsibilities, should be afforded the opportunity of a loving, forever home to live the remainder of their days,” said another, Sen. Phil Boyle, R-Suffolk County.
The The Beagle Freedom Project — whose work is featured in the video above — has mounted campaigns in several more states to get the law passed.
The New York law requires publicly-funded higher education research facilities to take reasonable steps to provide for the adoption of dogs and cats when they are no longer being used for scientific research.
While federal laws regulate animal research, they do not protect dogs and cats from being euthanized when their services are no longer needed.
Some research facilities, however, have instituted their own adoption programs.
“These dogs and cats deserve to live normal lives as companion animals once their time in the laboratory ends,” said Brian Shapiro, New York state director for The Humane Society of the United States.
“People who have adopted former research dogs and cats can attest to the resilience and affection of these animals once they are given the chance to flourish in a home environment,” he said.
Posted by John Woestendiek June 16th, 2016 under Muttsblog, videos.
Tags: adoption, animals, beagle freedom bill, beagle freedom project, beagles, dog, dogs, euthanasia, euthanized, freedom, homes, lab, laboratory, law, legislation, new york, pets, protection, research, research animal retirement act
If, like me, you tend to mindlessly credit the canine nose when you hear about a dog miraculously finding his way hundreds of miles back home, you might be interested in this other possible explanation.
Researchers have shown for the first time that the eyes of dogs have a version of the molecule cryptochrome 1 — the same molecule that gives bats, birds and certain other mammals the ability to perceive Earth’s magnetic fields.
It’s not clear yet that dogs possess magnoreception — that GPS-like ability that allows birds to return to the same spot every year — but researchers at the Max Planck Institute in Germany have shown that a version of the molecule that gives birds that ability is present in the retinas of dogs, wolves, bears, and more.
Magnoreception could help explain the mystery of why dogs tend to line up parallel to the north-south axis when they poop.
And many, more important, things, as well.
Presence of the light-sensing molecule gives some plants and animals almost a sixth sense, allowing them to regulate their circadian rhythms and find places they have left far behind.
But not humans. We’ve lost whatever cryptochrome 1 we might have had long ago — probably about the same time we started asking for directions.
According to the study, simply having cryptochrome 1 doesn’t necessarily mean that animals can perceive magnetic fields, but the presence could be a sign of that.
It has been found in the cone photoreceptors of some mammals — the same place it is located in birds.
Out of 90 species of mammals examined, researchers found only a few contained cryptochrome 1.
It was found in the eyes of dogs, wolves and foxes; five members of the weasel family, including ferrets and sea otters; orangutans and two types of macaques; brown bears and polar bears.
With further studies, scientists could find out if and how those animals are using it.
“…It is possible that these animals also have a magnetic sense that is linked to their visual system,” the researchers concluded.
It could explain why some animals approach certain prey from a certain direction, why dogs like to line up north to south to do their business and how so many a lost dog — in real life and movies — manages to find his or her way back home.
Posted by John Woestendiek February 25th, 2016 under Muttsblog.
Tags: animals, bats, bears, birds, cone receptors, crypochrome 1, cryptochrome, dog, dogs, eyes, foxes, germany, magnetic fields, magnoreception, magnoreceptors, max planck institute, molecule, research, retinas, science, sixth sense, study
Ten years after a dog was first successfully cloned, scientists have managed to produce the world’s first litter of pups to be born through in vitro fertilization.
In July seven puppies were born through IVF at Cornell University — five beagles and two “bockers,” or beagle-cocker spaniel mixes.
The achievement was not revealed until this week with the release of the research study.
Seems like science would have happened the other way around — that a “test-tube” puppy would have premiered long before we entered the even more science fiction-like era of cloned dogs becoming available on the marketplace.
But, while IVF has been used for decades in other animals, including humans, scientists had never succeeded in using it to produce a newborn pup.
Previous attempts to use IVF in dogs had resulted in very low rates of fertilization, and no live births at all once IVF embryos were transferred to a host.
“Since the mid-1970s, people have been trying to do [IVF] in a dog and have been unsuccessful,” said co-author Alex Travis, associate professor of reproductive biology at the Baker Institute for Animal Health in Cornell’s College of Veterinary Medicine.
What made it so difficult were some of the same factors that proved challenging in cloning dogs — females only ovulate once or twice a year, and their eggs are not transparent, making it harder to see the structures inside of the egg.
The Cornell researchers, in a joint project with researchers from the Smithsonian Institution, found that by waiting an extra day for eggs to mature before extracting them, they met with more success.
Adding magnesium to the environment where the sperm and egg met also helped with fertilization, the team found, according to a Cornell press release.
The achievement was revealed this week in a study published online Dec. 9 in the journal Public Library of Science ONE.
The seven surviving puppies (out of 19 embryos) are genetically the offspring of two different fathers (a cocker spaniel and a beagle) and three different beagle mothers, carried by the same beagle surrogate.
Unlike cloning, which involves transferring an existing (or dead) dog’s DNA into a donor egg, IVF involves the creation of a new genome through fertilization. Each each animal has a unique set of DNA.
The researchers say the development will open the door for preserving endangered canid species using assisted reproduction techniques.
It could also enable researchers to eradicate heritable diseases in dogs and facilitate the study of genetic diseases in dogs and humans, they say.
(Photo: Cornell graduate student Jennifer Nagashima and Smithsonian Conservation Biology Institute research biologist Nucharin Songsasen — lead author and co-author of the study — walk some of the puppies born through IVF; by Jeffrey MacMillan / Cornell University)
Posted by John Woestendiek December 10th, 2015 under Muttsblog.
Tags: animals, assisted, beagles, biology, bockers, cloned, clones, cloning, cocker spaniels, cornell, cornell university, dna, dog, dogs, egg, first, in vitro, in vitro fertilization, ivf, pets, puppies, pups, reproduction, research, science, sperm, study
Some researchers are suggesting that selfish mama dogs may have played a role in the early domestication of the species by keeping the good food to themselves, as opposed to sharing it with their pups.
As a result, the researchers theorize, pups and young dogs ventured out of the wild and into human communities where they didn’t have to compete as hard for food — at least not with their own mothers.
(Being a cartoonist at heart — albeit one who can’t draw — I am picturing a young pup, sneaking away from the home of his domineering mother with one of those sacks on a stick over his shoulder, muttering to himself, “That bitch. That bitch. That greedy bitch!”)
Sure, there may be some substance to this research, but it mostly makes me laugh.
The researchers conducted experiments with feral dogs in India, then theorized that ancestral dogs thousands of years ago must have behaved the same way.
First, they offered low-quality biscuits to mother dogs, and the mother dogs tended to share those with their pups, with no conflicts arising.
Then they brought out the good stuff. Protein-rich meat seemed to make the mother dogs forget their motherly ways, growling at their pups to keep them away, and even grabbing meat from the mouths of their puppies.
The authors, Anindita Bhadra and Manabi Paul of the Indian Institute of Science Education and Research, say ancestral dogs, once they reached 8 or 9 weeks old, became able to clearly distinguish between protein rich food sources and the un-nourishing filler their mothers were trying to pass off on them.
At that point, the researchers theorize, many young ancestral dogs would set out for farming communities where they had access to what humans threw away. There is evidence also that the earliest farmers fed these dogs, making life among humans even more appealing.
The theory, outlined in the journal Royal Society Open Science, could help to explain the origins of dog domestication and how some ancestral dogs so willingly elected to live with people instead of with their own kind, Discovery reports.
“Ancestral dogs” is kind of a safe term scientists use — just in case dogs didn’t evolve from wolves, but from some other species.
As for why ancestral dog moms turned so selfish when a good cut of meat became available, Bhadra said, “We feel that the mothers just tend to grab the best resources when available.”
Ancestral mother dogs are not available to respond to those charges, so I will speak for them:
“Hey, you think it’s easy giving birth to 14 kids at once, and then raising them? Alone?
“Yeah, where IS dad? Good question. Haven’t seen him since he knocked me up.
“So, yes, I get a little anxious, a little snippy. But I’ve got to feed the whole lot of them, and protect them. It’s not like I can walk into the Food Lion and get all I need. You have no idea how tired I am. And yes, I get hungry, too. If I am not nourished, how do you expect me to nourish all of them? Go research that, why don’t you?”
(Photo: From Lovethesepics.com)
Posted by John Woestendiek December 9th, 2015 under Muttsblog.
Tags: ancestral dogs, animals, dog, dogs, domesticated, domestication, feeding, food, greedy, humans, mothers, pets, puppies, pups, research, science, selfish, study, wolf, wolves