Dog Tail-Chasing Linked to High Cholesterol
Jennifer Viegas, Discovery News
March 24, 2009 -- A team of veterinarians has found a surprising link between compulsive tail-chasing in dogs and high cholesterol, according to a study published in the March issue of the Journal of Small Animal Practice.
The finding adds to a growing body of evidence -- mostly from studies on humans -- that high cholesterol may be a marker for behavioral problems such as panic attacks and obsessive compulsive disorder, which could be expressed by frequent tail-chasing falls in dogs.
Bouts of tail-chasing can also occur after a dog experiences physical trauma, surgery or illness, noted Hasan Batmaz, a member of the Faculty of Veterinary Medicine at Turkey's University of Uludag, who conducted the study along with a team of colleagues.
Certain breeds, such as bull terriers and German shepherds, seem to chase their tails more often than others.
For the study, the researchers took blood samples from 15 otherwise healthy dogs that were compulsive tail-chasers. To serve as controls, 15 dogs that rarely chase their tails were included in the study as well.
The tail-chasers had significantly higher cholesterol numbers -- including both HDL and LDL -- compared with the control dogs, the researchers found.
The reason, they said, could be that high cholesterol levels glob up cell membranes at the microscopic level, affecting the flow of brain hormones such as serotonin that are involved in mood and behavior.
Female dogs were more likely to be obsessive tail-chasers, but the researchers aren't sure why.
Past studies have found that people with panic disorders and certain phobias often have higher cholesterol levels, possibly as a result of increased activity of hormones tied to the "fight or flight" response.
Lisa Peterson, a longtime dog breeder who is director of communications for the American Kennel Club, was surprised by the new study.
"It's an interesting hypothesis, especially as we don't usually test for cholesterol in dogs," she told Discovery News.
Peterson explained that since high cholesterol in dogs doesn't always lead to the same health issues as it does in humans, such as clogged arteries, dogs aren't tested for their serum lipid levels as part of their annual wellness exams.
"Blood pressure isn't usually measured for dogs either, unless the dog is exhibiting extreme symptoms," she added.
As for tail-chasing, she said, "this is usually just a puppy thing that happens when young pups discover they have a tail."
But when tail-chasing becomes compulsive, she said the behavior could be due to "nature or nurture," meaning genetic or environmental causes, including "a stressful incident trigger."
Although a change to a lower fat diet could help alleviate compulsive tail-chasing in dogs, Peterson doubts high cholesterol is always a result of overeating, since "manufactured pet foods must all meet governmental regulations for protein, ash, fat and water content, and more."
"Dogs don't elect to gorge themselves on french fries all day," she said.
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