‘Ambitious but possible’: The project that might boost your dog’s lifespan

This story is part of the May 17 edition of Good Weekend.See all 13 stories.

It’s the eyes. Whether they are the excited peepers of a puppy whose whole body is shaking with joy at the thought of licking your face or the wise, old ones of a shelter dog, abandoned by the family he loved his entire life, those soulful, expressive eyes will get to you. Look into a dog’s eyes, and you’ll see a being, some may say a soul, yearning to love and be loved.

The truth is, dogs are capable of unconditional love. And it’s only through bonding with a dog that the wonder of this fully reveals itself. Who is this furry creature that greets you when you’ve been out to the shops for an hour as if you’ve come home from a year in Alaska? Who can tell the sound of your car engine from a hundred others on the street and whose heart practically explodes with joy at the mere sight of you? Who will curl up in your bedding when you’re out, just to be immersed in your scent like a lovesick teenager?

And no matter how long you’ve been absent, there are no remonstrations, just a madly wagging tail and jumps for joy that you have come home, indeed that you exist at all. And if you encourage it, the bond grows, through thousands of walks, road trips, games, swims, adventures, naps together, in sickness and in health. The wordless engagements, the shared understandings created through hours spent just hanging out, make the bond ever stronger. The physical affection, the toothy smile, the gorgeous nose leather, the general cuteness and doggie smell all work their spell on you.

But all too soon the pace of the walks begins to slow, the energy winds down. The happy dance of gratitude when dinner hits the bowl is reduced to a wag or two of the tail. The puppy face, once golden, tan, jet-black or brindle, grows frosty, the jumps of joy less convincing as arthritis and other conditions inhibit movement.

Dogs, as we know to our cost, age much faster than humans. Sometimes it’s as if you can see it happening in real time. And while they have their own canine-exclusive ailments – such as distemper, parvovirus and leptospirosis – they are also prey to those general complaints we see in humans, such as cancers, anxiety, diabetes, even dementia.

Perhaps it’s no wonder the love of dogs has inspired scientists to look into why they age as quickly as they do, and to see if anything can be done about it. Advances are being made in understanding the physiology of dogs and in drug treatments designed to prolong what is called the “healthspan” – the number of years a dog lives a healthy, disease-free life – and overall longevity, or the total number of years lived.

So are scientists close to finding the doggie fountain of youth and, if they are, what implications might that have for extending our own lives? Well, the truth is that progress is slow – but promising.

Founded in 2018, the US-based Dog Aging Project is the largest and most ambitious canine health study ever undertaken, with more than 50,000 dogs enrolled. Broadly, the goal is to understand how genes, lifestyle and the environment influence dog health and ageing. Speaking to Good Weekend from the University of Washington in Seattle, Professor Matt Kaeberlein, co-founder of the project, explains that there are essentially two components to it.

Matt Kaeberlein, co-founder of the Dog Aging Project, with Dobby, his German shepherd who died last year aged 14.Credit: Courtesy of Matt Kaeberlein

“The largest is a longitudinal study of ageing,” he says. “All that means is that it’s purely observational. We’re following dogs living with their owners over time and collecting data, with the aim of understanding the most important genetic and environmental factors that influence health and longevity. The other is a clinical trial of [the drug] rapamycin, to test whether it can slow ageing and increase lifespan and health span in dogs.”

The project is engaged in a huge double-blind, placebo-controlled, clinical trial of the drug. Originally developed as an immunosuppressant for organ-transplant patients, rapamycin has found recent scientific favour as a potential anti-ageing drug. Isolated in 1972 from a bacterium found on Easter Island (Rapa Nui), rapamycin was found to significantly extend the lifespan of worms, yeast, flies and mice in the early 2000s.

There are other studies and treatments as well, notably from the San Francisco-based biotech Loyal, which has three dog longevity drugs awaiting full US Food and Drug Administration approval status. LOY-001 and LOY-003 are focused on extending the lifespans of larger dogs, who – for reasons thought by Loyal to be linked to an overactive growth hormone – live far shorter lives; and LOY-002, which will target almost all dogs except the tiniest of breeds.

When it comes to longevity in dogs, size really does matter. Closer to home, Dr Jack Da Silva – a senior lecturer at the University of Adelaide – has an explanation for why larger breeds live shorter lives. “Larger breeds have shorter lifespans mostly because they have higher rates of cancer,” he says. “Bigger animals are the result of more cell division. The more cell division there is, the more likely mutations are to arise.”

This could be bad news for tall humans as well. But there is a twist in the tale. While bigger mice, for example, have higher cancer rates than their smaller counterparts, bigger species – such as elephants – don’t. Da Silva says this is down to Peto’s paradox. “It’s a simple idea,” he says. “Larger species have evolved greater cancer suppression mechanisms. They invest more in searching for DNA damage that might cause cancer, in DNA repair and repairing mutations that may lead to cancer. They invest more in the
immune system that helps suppress cancer.”

So why are bigger dog breeds more susceptible to cancer and therefore live shorter lives? “It’s probably because we produced these large breeds fairly recently, and they haven’t had time to evolve these cancer-suppressing mechanisms that you see in big species,” says Da Silva.

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In the US, unlike the relatively straightforward university research-funding processes we have in Australia, the funding of large scientific projects is a mélange of government research grants and philanthropy.

You get the sense Matt Kaeberlein has struggled with funding – and won. “We’ll get to the end point and be able to unblind [revealing which dogs received the drug] within this funding period,” he says. “The longitudinal study hasn’t had its funding renewed by the National Institutes of Health yet. There is a lot of effort being put into a large grant to fund that whole project and individual smaller grants to fund pieces of it, as well as efforts towards philanthropic funding.”

‘In dogs, seeking a 25 per cent increase in lifespan might be ambitious but possible.’

Matt Kaeberlein

Kaeberlein and his colleagues recently set up a non-profit organisation called The Dog Aging Institute to support the Dog Aging Project’s research. “We secured a couple of million dollars in philanthropic funding in the last year to keep the infrastructure in place and to support it,” he says. “So, that’s the state of the project right now; it’s still going. We’re able to maintain all of the dogs that are currently in the study, but we’ve really had to slow down on new science, sample collection, processing, things like that.”

And what does he make of the funding landscape under what is looking to be the most unpredictable and capricious president in US history? “It’s too early to tell,” he says. “Obviously, there’s a lot of uncertainty about what’s going to happen with federal funding for research. I would say at this point people are carrying on, trying to maintain some cautious optimism that things will work out.”

Assuming the huge rapamycin trial survives the current US funding uncertainty and proves effective at increasing healthspans and lifespans, how much benefit might we reasonably expect?

“When you target the biology of ageing, it seems like you slow multiple functional declines in diseases simultaneously; it’s called compression of morbidity,” says Kaeberlein. “The idea is you push the diseases back a little bit later in life. In dogs, seeking a 25 per cent increase in lifespan might be ambitious but possible. However, it wouldn’t shock me if you could get a 20 per cent increase and maybe a little bit more, which is not insignificant. For a dog who’s going to live 12 years, you’re talking about another 2-2.5 years of healthy life.”

Kaeberlein with Dobby: “The grief comes and goes. We had 14 years with him, which for a German shepherd is pretty good.”Credit: Courtesy of Matt Kaeberlein

Not the fountain of youth, then. At least, not yet. “Part of me would say the science is going to keep maturing,” says Kaeberlein. “With new tools, like AI, who knows what’s going to happen. There are lots of reasons for optimism.”

If you look up Kaeberlein on the internet, you’ll find a fit-looking man in his mid-50s who takes care of himself. Among the images that come up, many feature his beloved German shepherd, Dobby. He goes quiet for a moment when I ask how Dobby is doing.

“Dobby passed in October,” he says. “It was one of the toughest things in my life. Anybody who’s a dog person understands just how tough it is. It was brutal. Just yesterday, I was driving back from the grocery store and I suddenly missed him terribly. The grief comes and goes. We had 14 years with him, which for a German shepherd is pretty good.”

Such is the desperation to keep our beloved animals, that those with the means to do so have had their pets cloned. Singer Barbra Streisand did this with two of her dogs in 2018, but the star said she was a little disappointed. A dog’s personality is formed through all kinds of genetic and environmental quirks and through unique experiences.

“You know, the clone is not going to be your dog,” says Kaeberlein. “But I’m certainly not going to judge [Streisand] for that. I’d be lying if I said that didn’t pass through my mind when we lost Dobby. I can totally see why somebody would do that. But if you’re expecting that clone to be your original companion, they’re not. It’s going to be a different individual.”

If we can’t clone them, and all we can expect in the near future is just a couple of years – at best – of drug-enhanced longevity, what can we do to prolong our dogs’ lives?

“Don’t let your dog get obese is the starting point,” says Kaeberlein. “And exercise them. One thing that has come out of the longevity project is that dogs who get more exercise are much less likely to develop dementia. So those kinds of lifestyle factors are super-important.

“And data shows that when people interact lovingly with their companion animals, both lives are improved. Pet your dog, cuddle your dog, love your dog. These interactions have a positive effect on the physiology of both the dog and the human.”

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