Everything Dogs Can Teach Us About Aging

Anyone who has shared their life with a dog will have noticed that the way it manifests in them over the years is very similar to that of humans: from playful and unruly puppies, they become less active and anxious as they grow older and some illnesses shape their behavior as they age. The similarity, however, is not just superficial. There are many parallels in other respects that have led dogs over the past decades to be seen by science as an increasingly valuable role model for learning more about how we age and perhaps how better. to get old.

The topic is the primary focus of the Canine Longevity Consortium, a network of prestigious research centers around the world that have allocated enormous resources to obtain useful information. In this context, one of the most ambitious initiatives is the “Dog Aging Project”, an initiative funded to the tune of $ 15 million by the United States government to try to identify the biological and environmental factors that contribute to the aging. healthy dogs.

This project – which is based on the University of Texas College of Veterinary Sciences and the Center for Biomedical Sciences at the University of Washington – aims to monitor 10,000 domestic dogs throughout their lives, involving dozens of veterinarians, gerontologists, epidemiologists, geneticists, pathologists and sociologists in what is the largest study of its kind ever undertaken.

AN IDEAL MODEL

Beyond the fact that dogs tend to change in much the same way as humans as they age, there are many reasons that have led scientists to conclude that they are an invaluable model for obtaining information on human aging.

In principle, today dogs get sick and die from causes more and more similar to us. Over the years, they develop heart disease, arthritis, cataracts and many of the same cancers; and they even become delicate and forgetful. But in addition, their life is often prolonged by expensive medical interventions.

Domestic dogs are, in many ways, a reflection of our own species. Unlike most other animal models used to study aging, they are not in a laboratory but share our same environment: they sleep with us, they also consume processed foods, and they have access to medical care similar to this. that they receive. the people. But they also exhibit genetic variability as diverse as humanity.

Another benefit of the “canine model” that scientists find is a certain genetic convergence between the two species, given by the fact that humans and dogs, influenced by the environment we share, have evolved together for thousands of years. .

The dominant theory is that humans and canines met tens of thousands of years ago, initiating a process of mutual domestication that brought survival benefits to both parties. Whereas the most sociable wolves have benefited from the conservation of the remains; ancient humans who tolerated these creatures found them to be good hunting companions and alarm systems, and so they thrived in tandem.

In fact, as some studies point out, that of dogs and humans is a relationship that continues to evolve to this day. In addition to keeping our homes safe and consuming leftovers from our meals, dogs who live with humans have been found to live longer and living with them improves the quality of life, especially for children and people. Elderly: People with dogs tend to weigh less, exercise more, and sleep better.

And no less important for research purposes is that dogs age much faster than humans, so in less time more information can be obtained from them and at a much lower cost: you don’t You don’t have to wait maybe 80 years to come to a conclusion.

CANINE AGE

One of the main goals of studies such as the Canine Aging Project is to determine to what extent the physical deterioration observed in aging dogs and humans is due to the environment or living conditions, and to what extent biological conditions.

One of the things to know in the first place is if there is anything in the DNA of dogs that explains why some of them live remarkably long lives, a fact that could be very helpful in prolonging healthy aging. among people. .

In this regard, the big unanswered question is why, if in general in mammals larger species tend to live longer than small ones, the opposite is true in dogs: small breeds tend to have the longest longevity.

This remarkable difference in longevity observed between breeds of dogs is one of the reasons that make it difficult to establish with precision the number of human years corresponding to a dog. Some recent research suggests, in fact, that the usual calculation of 1 by 7 might not be the best for estimating their age.

Based on comparing patterns of chemical changes in DNA between humans and dogs (specifically a process called methylation that does not change the content of genes, but changes their activity), a survey concluded that the best computation for equating the age of dogs with humans is a bit more complex than what we usually use.

This involves multiplying the natural logarithm of a dog’s age by 16 and then adding 31. So if a dog is 6 years old, multiply its natural logarithm, which is about 1.8, by 16, which is almost 29, and add 31. In conclusion, this animal would have an age comparable to a man of 60 years.

SOME RESULTS

The importance of establishing a more or less precise calculation for comparing the ages of dogs and humans is that it allows researchers studying canine aging to translate the results in humans. It is a particularly valuable resource for evaluating the changes that the passage of time produces in behavior.

One of the most important studies of dog personality changes over time is the Clever Dog Project at the University of Vienna, which has worked with domestic Border Collies. Its authors have scientifically verified that dogs’ behavior changes with age, just like in humans: they become less active and less anxious.

How did you check it? Border Collies have been subjected to various tests such as evaluating their reaction to being petted by strangers entering a room or being faced with a sausage out of reach. Experiments like these have shown that, “like some people, all dogs change behavior with age, but some do so much less than others,” says Borbalu Turcsan, one of the authors of the research. . The scientific term for this condition of maintaining youthful qualities is “neotenia” and it is a common characteristic in some older dogs that science seeks to learn.

“Anything you do to help your dog age well should be done with him”

Another interesting finding in this regard comes from a study by neuroscientist Elizabeth Head, who studies old Beagle dogs at the University of Kentucky.

After observing that once they reach middle age, dogs resist change, need more time to learn new things, and begin to decline on memory tests, this researcher found that at age 7, even healthy animals showed signs of beta-amyloid plaques, which are hallmarks of Alzheimer’s disease. But he also found that a third of them ended up developing the so-called “canine dementia”. This is a percentage similar to that of the population over 85 who develop Alzheimer’s disease in their country.

More interestingly, “dog ID tags look a lot like human tags, more than those found in our fellow primates,” says Head, who admits she doesn’t know why. “It could be that living in our environment – sharing our food, our water, our home – makes dogs more vulnerable to this disease”, which would be, as she understands, “a sort of accidental side effect of domestication. “.

In other studies, the same researcher found that a diet rich in antioxidants and behavioral enrichment – a series of exercises for memory and teaching new skills – can significantly delay or reduce the development of plaques and plaques. memory impairment.

As she seeks to perfect this diet and tries to stop brain deterioration in middle-aged animals altogether, the neuroscientist argues that “anything you do to help your dog age well, you have to do it with” him: eat good quality food, go out for a walk every day even when it rains, take a nap and become overjoyed when a loved one walks through the door, even if it happens five times a day.