Scientists seek answers to the canine aging process and lifespan
By Kim Campbell Thornton
How long do dogs live? I think we can all agree that it's not nearly long enough. Canine lifespans vary from as short as 6 to 8 years for certain giant breeds to an astounding 20-plus years for some tiny dogs. Owners of small and medium-size dogs can generally expect their companions to live 10 to 15 years.
Diet, good care and genetics all play a role in the length of a dog's life, but two researchers at the University of Washington in Seattle are hoping to learn more about how dogs age, as well as whether the aging process can be delayed and the lifespan lengthened. The Dog Aging Project (DAP), headed by Daniel Promislow, Ph.D., and Matt Kaeberlein, Ph.D., plans to track 10,000 dogs in homes around the United States to get a sense of how genetic and environmental factors affect aging in dogs.
As dogs -- and humans and other animals -- age, organs and tissues break down, increasing the risk of age-related diseases such as cancer, cardiovascular disease, kidney disease, Alzheimer's disease and more. Age is a greater risk factor for these diseases than diet, weight and exercise.
"The big picture behind what we're trying to do is to understand the aging process so we can delay the onset and progression of all these diseases," Dr. Kaeberlein says. "It's sort of a fundamental shift from the traditional medical approach, which is to wait until dogs -- or people -- are sick, and then try to treat the disease."
The dogs in this observational study will include many different breeds in different environments: short-lived dogs, long-lived dogs, dogs in wealthy households and dogs in more modest households. The researchers will look at not just how long the dogs live, but also at how environmental factors affect them as they age.
Included in the DAP will be a smaller study, with up to 36 pet dogs in the Seattle area. It will look at whether a drug called Rapamycin -- used to prevent organ transplant rejection in humans -- can slow aging, extend canine lifespans and improve quality of life. The drug has been shown to increase lifespan in many different organisms, Dr. Kaeberlein says, as well as improve cognitive, cardiac and immune function in animals such as mice.
"There's been accumulating evidence over the past several years that not only do they live longer, but that the aging process itself is slowed down," he says.
Of the 46 dogs whose owners have expressed interest in enrolling them in the Rapamycin study, only 26 dogs so far have met the criteria to be included: at least 6 years old, weighing at least 40 pounds and with no pre-existing conditions. Among them are golden retrievers, a greyhound, Labrador retrievers, German shepherds and mixed breeds.
In both studies, dogs are good subjects because their shorter lifespan allows scientists to see results in a decade or less.
"If we had a large enough sample size, we could know in three years -- certainly in five years -- the extent to which Rapamycin improved healthy aging in dogs," Dr. Promislow says. "And for a longitudinal study of age, where we want to follow dogs throughout life and understand the genetic or environmental factors that affect aging and disease in dogs, you can do that in a decade. That's not possible in that timeframe in people."
The eventual results could have implications for humans, but the dog-loving scientists say their research is about more than that.
"We're both determined to find ways to improve the quality of life for dogs," Dr. Kaeberlein says. "This is not just about finding something that will help people. It might be good for dogs and their owners."
Essential oils can
be toxic to pets
Q: I've been using an essential oil diffuser in my home, and I'm wondering if the oils are safe for use around my pets. Can inhaling the scents harm them? What about topical use? -- via email
A: Essential oils are extracted from plants, usually by distilling flowers, leaves, wood, bark, roots, seeds or peel. Some people use them medicinally, by inhaling them or applying them to the skin.
Pet owners who are interested in holistic remedies sometimes use essential oils to fight flea infestations or soothe hot spots or other skin conditions. It's important to use these oils cautiously around pets, however. They are powerful and can be toxic or even fatal if misused. Cats are especially at risk because their livers aren't able to metabolize certain drugs and toxins, including essential oils such as melaleuca (tea tree oil), pennyroyal, D-limonene and linalool.
According to my colleague Sharon Gwaltney-Brant, DVM, a toxicology specialist who spoke on this subject at a veterinary conference, the most common signs seen in pets who have essential oils applied to the skin are loss of coordination, muscle weakness, depression and behavior changes. Small dogs have become temporarily paralyzed when owners applied melaleuca oil down the spine as a topical flea treatment. Cats improperly exposed to the oils can develop liver failure. Pets who lick or ingest the oils may vomit or have diarrhea or suffer mouth burns. Inhaling the oils can not only irritate your pet's sensitive nose, but can also cause aspiration pneumonia. Pet birds have an extremely delicate respiratory tract, and you should never use scent diffusers or scented candles in their presence.
In essence, it's important to be careful when using these products. Never let pets lick them off your skin, and always check with your veterinarian before using essential oils on or around your pets. -- Dr. Marty Becker
Do you have a pet question? Send it to email@example.com or visit Facebook.com/DrMartyBecker.
Coat color may affect
-- Does your calico have cattitude? Science says: Yes. According to a study conducted by researchers at the University of California, Davis, calico and tortoiseshell cats are more likely to be assertive in their interactions with humans. In other words, they don't hesitate to hiss, chase, bite, swat or scratch to get their point across to owners and veterinarians. The information, acquired by surveying more than 1,200 cat owners and published in the Journal of Applied Animal Welfare Science, confirmed that cats who come in those patterns can have spirited temperaments. Some call them "difficult"; we like to think of them as, uh, forceful communicators. Want a more laid-back cat? Choose one with a solid-colored coat.
-- Endangered rhinos have some new best friends: anti-poaching dogs. One of them is Larry, a 2-year-old Belgian Malinois employed in Swaziland, a country in southern Africa where rhinos are at high risk from poaching gangs. Larry and other dogs, including bloodhounds and foxhounds, track and apprehend poachers and scent out rhino horns and ammunition smuggled through airports. Anti-poaching dogs and their handlers also work to protect rhinos in South Africa's Kruger National Park and Kenya's Ol Pejeta Conservatory. Elephants and gorillas benefit, too, from the approximately 100 dogs who help to protect African wildlife.
-- When Annabelle slipped down an icy embankment in Orange, Massachusetts, and became trapped in some brush, her pal Jacques did the sensible thing: He called the police. Officers had been trying to catch the west Highland white terriers, who had escaped after their owner was taken to the hospital, but they couldn't get close to them until Jacques ran up to an officer and barked, then led him to Annabelle. Officers were able to use a ladder to rescue her, and brought them in until they could be reunited with their owner. Thank goodness for "Lassie" reruns. -- Dr. Marty Becker, Kim Campbell Thornton and Mikkel Becker
ABOUT PET CONNECTION
Pet Connection is produced by a team of pet-care experts headed by "The Dr. Oz Show" veterinarian Dr. Marty Becker and award-winning journalist Kim Campbell Thornton. They are affiliated with Vetstreet.com and are the authors of many best-selling pet-care books. Joining them is dog trainer and behavior consultant Mikkel Becker. Dr. Becker can be found at Facebook.com/DrMartyBecker or on Twitter at DrMartyBecker. Kim Campbell Thornton is at Facebook.com/KimCampbellThornton and on Twitter at kkcthornton. Mikkel Becker is at Facebook.com/MikkelBecker and on Twitter at MikkelBecker.
CAPTIONS AND CREDITS
Caption 01: Studies of canine longevity could have benefits for dogs and humans. Mouse, a 6-year-old husky-shepherd mix, is participating in the Dog Aging Project's Rapamycin study. Photo credit: John Benavente Position: Main Story
Caption 02: The genes that dictate a cat's coat color and pattern may also be linked to temperament. Position: Pet Buzz/Item 1