I was recently alerted to a lecture discussing how to “double your dog’s lifespan”. It is an understandable topic of interest. Every dog owner wants more time with their companion and, more importantly, we want those extra years to be healthy, comfortable, and with a good quality of life.
However, while the science behind canine longevity is growing and we are understanding more, there are those who peddle misinformation in order to capitalise on our desire to have our pets around for as long as possible.
One of the claims reportedly made during the lecture was that only 10% of a dog’s health outcomes are determined by genetics, with the remaining 90% influenced by environment and lifestyle. Meanwhile, we were told (by the company whose professional supporter gave the lecture) that “genes are overrated” and that epigenetics is the true driver of health and ageing, because “the reality is epigenetics is a stronger pathway – just one that doesn’t fit with the big-pharma narrative or their drugs as commodities financial system.”
For many of us, hearing “big-pharma narrative or their drugs as commodities financial system” tells us everything we need to know about the company pushing these narratives, but for those who still want to understand the nuance behind the statements, we can look at what the research says on dog longevity (though we will barely begin to scratch the surface of the available evidence). Take, for example, a 2024 systematic review in the Journal of Veterinary Science, which summarised:
The majority of research on factors which modify longevity in pet dogs has included non modifiable factors such as sex, breed, and body size. This appears to mostly be due to the fact that these factors are studied frequently as part of the demography of any study …This is useful information to both prospective pet owners and veterinary professionals when it comes to decision-making in the process of obtaining a dog (e.g., selecting breed and sex of dog), and to clinicians in determining courses of treatment. However, the research about how to best extend the lifespan of pet dogs with changes to their lifestyle is less robust.
Are dogs living shorter lives?
A common claim is that modern dogs are becoming sicker and dying younger, usually citing commercial diets, medications, vaccines, or environmental toxins. The evidence does not seem to support this narrative. Multiple studies examining canine longevity across different countries have found that dogs are generally living longer than they did in previous decades. Advances in veterinary medicine, improved nutrition, better parasite control, vaccination, diagnostics, and welfare standards have all contributed to increased life expectancy.
Again, according to the 2024 systematic review:
There is a wide difference in longevity among individual dogs, and determining which factors may contribute to lengthening or shortening their lives is of utmost interest to dog owners, veterinary professionals, researchers, and pet industries, alike. Indeed, a US veterinarian made headlines when he claimed that dogs of today are actually living shorter lives than decades previous. However, a review of scientific studies in multiple countries has proven that if anything, dogs’ lives are getting longer (although the tools used to measure longevity in dogs are imperfect).
That does not mean all breeds are thriving equally. Certain breeds continue to suffer from serious health problems, particularly those with extreme conformations. However, population-level data do not support the claim that dogs as a whole are experiencing dramatically shortened lifespans.
Why some dogs live longer than others
One of the strongest and most consistent findings in canine longevity research is the relationship between body size and lifespan. Unlike most mammals, where larger species tend to live longer, larger dog breeds generally have shorter lives than smaller breeds.
Research has repeatedly shown that adult body size is inversely associated with lifespan in dogs. In simple terms, the larger the dog, the shorter the average lifespan tends to be.
Breed also matters but, as we well know, there are many other factors that play into the health of an animal. Life table data from the UK companion dog population found wide variation between breeds. In one study, Jack Russell Terriers had one of the longest life expectancies at birth, while French Bulldogs had one of the shortest. Other research has also found that brachycephalic dogs – flat-faced breeds such as French Bulldogs, English Bulldog and Pugs – have an increased risk of shorter lifespan.
Are genes really “overrated”?
According to the lecture, genes are “overrated”, accounting for only 10% of a dog’s health outlook. Instead, we were told, epigenetics is the more important factor. Genetics is the study of heredity and the variation of inherited characteristics that animals are born with; epigenetics can influence how those genetics are expressed throughout life.
In dogs, genetics clearly plays a major role in health and longevity. Certain breeds are predisposed to specific diseases, cancers, heart conditions, neurological disorders, joint problems, respiratory compromise, and structural abnormalities. And again, large breeds – as determined by their genes – consistently have shorter average lifespans than smaller breeds, while brachycephalic breeds face well-documented health challenges associated with their conformation.
At the same time, environmental factors such as nutrition, body condition, exercise, disease exposure, stress, stress of the dam (the animal’s female parent), reproductive status, and access to veterinary care can influence how those genetic predispositions are expressed. This is where epigenetics becomes important.
The scientific evidence does not support choosing one over the other, and certainly not a claim of a 90/10 split. Instead, ageing is increasingly understood as the result of complex interactions between genetic inheritance, epigenetic regulation, environment, lifestyle, disease, and chance.
What actually drives ageing in dogs?
Modern ageing research has moved far beyond the idea that ageing is simply ‘wear and tear’. Scientists now recognise a number of biological processes that appear to drive ageing across many species. These are often referred to as the ‘hallmarks of ageing’, and include genomic instability, epigenetic alterations, mitochondrial dysfunction, cellular senescence, altered nutrient sensing, chronic inflammation, stem cell exhaustion, immune dysregulation, and changes in communication between cells.
Many of these processes are interconnected. As cells age, DNA becomes more vulnerable to damage, repair systems become less efficient, inflammatory pathways become more active, and tissues gradually lose their ability to regenerate and function normally.
One particularly exciting area of research involves epigenetics. Unlike genetic mutations, which alter DNA sequences, epigenetic changes influence how genes are switched on and off. These changes accumulate throughout life and can be measured through DNA methylation patterns.
Researchers have now developed ‘epigenetic clocks’ capable of estimating a dog’s biological age by measuring these methylation changes. Remarkably, some of these clocks work in both dogs and humans, highlighting how similar the ageing process appears to be across mammals.
However, identifying biomarkers of ageing is not the same as proving that ageing can be dramatically reversed. An epigenetic clock can help researchers measure aspects of biological ageing, but it does not prove that a supplement, diet, detox or lifestyle programme can double lifespan.
Lifespan vs health
One important distinction in this discussion is the difference between lifespan and health, or to use a term coined by Brennan McKenzie VMD in Veterinary Practice News, ‘healthspan’. Lifespan means how long an animal lives, healthspan means how much of that life is spent in good health.
Most canine ageing research is not simply trying to make dogs live as long as possible. The goal is to improve and maintain their health; to delay frailty, maintain mobility, reduce chronic disease, support cognitive function, and preserve quality of life.
We would not advocate for quantity of life unless it is paired with great quality of life.
Proven longevity science
If there is one intervention that repeatedly appears in ageing research, it is maintaining a lean body condition. Yet, despite repeated messaging against obesity, our pet population is overwhelmingly overweight – research shows that between 50% and 60% are obese, and 74% of vets believe pet obesity levels are increasing.
One 2002 canine longevity study followed Labrador Retrievers throughout their lives. Littermates were assigned either to a control group or to a calorie-restricted feeding programme designed to maintain a lean body condition. Apart from food intake, the dogs received the same veterinary care and lived under similar conditions. Dogs maintained at a lean body condition lived almost two years longer on average and developed age-related diseases later than their counterparts.
More recent reviews continue to support the importance of body condition and weight management. Overweight dogs consistently experience shorter lifespans and increased risk of chronic disease compared with dogs maintained at an ideal body condition.
This is perhaps one of the most important messages for owners: while cutting-edge anti-ageing therapies remain experimental, maintaining a healthy weight is something that can be implemented today and is supported by decades of evidence.
That does not mean dogs should be placed on extreme diets. Calorie restriction studies are carefully controlled, and inappropriate restriction can cause harm, particularly if it leads to nutritional deficiencies or loss of muscle mass. Sensible, pragmatic feeding, managing begging behaviours, and engaging in enrichment feeding can all play a part. The practical message is far simpler: keep dogs lean, well-muscled, appropriately fed, and regularly monitored by a veterinary professional.
What about supplements and longevity products?
When it comes to products that claim to be able to elongate the lifespan of your pet, you should be highly skeptical. The growing interest in canine longevity has created a market for supplements, diets, and products claiming to slow ageing or extend lifespan. At present, evidence supporting many of these claims is limited or absent. Notably, the company that posted this longevity lecture defended its claims by suggesting that its science “doesn’t fit with the big-pharma narrative of their drugs as commodities financial system” – while selling an unproven health product, presumably with a rather tidy profit.
Some promising pharmaceutical approaches are currently under investigation. For example, researchers are studying interventions that target metabolic health, growth pathways, and age-related frailty. Some medications have been studied in ageing research, and some companies are developing drugs specifically intended to extend healthy lifespan for dogs.
For a treatment to be recommended responsibly, it needs controlled studies, appropriate safety data, and meaningful clinical outcomes. It is not enough to show that something changes a biomarker. We need to know whether it actually helps dogs live longer, healthier lives without unacceptable risks. Until those data exist, extraordinary claims should be treated with appropriate scepticism.
As Brennan McKenzie VMD wrote in Veterinary Practice News:
Not surprisingly, excitement about the burgeoning field of canine geroscience and the potential to extend healthspan and lifespan and improve patient welfare has led to a proliferation of approaches not always based on solid science. Proponents of various diets and supplements often claim these can extend lifespan, but there is not yet reliable data to support such claims. Some veterinarians are already prescribing off-label drugs approved for other uses in humans… with claims about longevity benefits.
These claims have also not yet been proven in people or dogs. Waiting for new treatments to be available is tough, especially when our patients and our own pets are visibly aging. However, the best way to effectively extend healthy lifespan in dogs and to ensure our interventions do more good than harm is to follow a rigorously scientific and evidence-based approach.
What owners can actually do
Epigenetic mechanisms are, of course, of great interest, and play a role in longevity. According to a 2024 review paper:
The recognition of the interaction between environmental and genetic factors in aging remains pivotal. Modulating epigenetic mechanisms through interventions in the living environments of these animals may represent a promising strategy for enhancing the quality of physiological aging. While direct intervention in the genetics of adult animals is not feasible, epigenetic regulation offers a potential lever to promote long-term health and well-being.
However it is important to recognise that, when it comes to longevity, the factors influencing it are vast and complicated. Yet, there are some ways to support your pet to help ensure the healthiest possible lifespan. These include:
- Maintaining a healthy body condition
- Feeding a complete and balanced diet
- Maintaining your pets hydration status
- Avoiding obesity and providing regular, appropriate exercise
- Supporting muscle mass and mobility into older age
- Keeping up with preventative veterinary care
- Treating pain and chronic disease promptly
- Considering breed-related health risks when choosing a dog
- Avoiding breeding practices that prioritise appearance over welfare, or support low-welfare breeding
- Supporting mental stimulation and quality of life throughout ageing
These interventions may not sound revolutionary, but they are all actionable.
The future of canine ageing research
As McKenzie’s 2024 Veterinary Practice News article explained:
As with other risk factors impacting canine health, such as obesity, genetics, neutering, and specific diseases, it is unlikely a single, perfect “silver bullet” will be found that eliminates the risks associated with aging. Extending healthy lifespan will ultimately involve a combination of approaches that include lifestyle interventions, such as diet and exercise practices, and medical interventions, such as drugs, gene therapies, and others not yet identified.
Scientists increasingly understand ageing as a collection of biological processes that may, at least in part, be modified. Research into epigenetic clocks, metabolic health, frailty, body size, growth pathways, and cellular ageing is opening exciting new avenues for improving the lives of dogs. Dogs may also be uniquely valuable in ageing research because they share our homes, environments, and many of the same age-related diseases. This makes them a potentially important bridge between laboratory studies and human medicine.
However, we must be careful not to let announcements outrun evidence. There is currently no secret diet, supplement, detoxification protocol, or anti-pharmaceutical philosophy proven.
What we do have is a growing body of research showing that ageing is complex, that genetics and environment both matter, and that healthspan may be a realistic target for future interventions.
Until then, the most effective path forward is the same one veterinary medicine aims to follow: curiosity, evidence, compassion, and a healthy scepticism of claims that sound too good to be true.
References
- Dog longevity | Liverpool John Moores University
- Longevity of UK Dog Breeds: Research | Dogs Trust
- Frontiers | Demographic Change Across the Lifespan of Pet Dogs and Their Impact on Health Status
- Longevity of companion dog breeds: those at risk from early death | Scientific Reports
- Nutrition Research in Aging Dogs and Cats: What We Know and What We Need to Do
- Life tables of annual life expectancy and mortality for companion dogs in the United Kingdom | Scientific Reports
- Genetic, epigenetic, and environmental factors influencing dog lifespan: a systematic review
- The expanding universe of canine aging science – Veterinary Practice News
- Aging at scale: Younger dogs and larger breeds from the Dog Aging Project show accelerated epigenetic aging – PMC
- DNA methylation clocks for dogs and humans – PMC
- Dog Aging: A Comprehensive Review of Molecular, Cellular, and Physiological Processes
- Pet Obesity: data & statistics | UK Pet Food
- State of Pet Obesity in the United States
- Exceptional longevity and potential determinants of successful ageing in a cohort of 39 Labrador retrievers: results of a prospective longitudinal study – PMC
- Effects of diet restriction on life span and age-related changes in dogs, Journal of the American Veterinary Medical Association
