In a development that raises hopes as well as ethical questions, several biotech startups are racing to create treatments aimed at extending the healthy lifespan—often called “healthspan”—of pets. Driven by robust venture capital funding, these companies are investigating everything from hormone-suppressing tablets to targeted gene therapies that promise to stave off age-related diseases in cats and dogs.
One leading voice in the field is Celine Halioua, founder of San Francisco-based startup Loyal. Her company has attracted more than $150 million in investments to develop what it hopes will be the first widely available lifespan-extension drug for dogs. Loyal’s scientists point to a key observation: Large dog breeds, such as Newfoundlands or Great Danes, tend to have shorter lifespans than their smaller counterparts, like Chihuahuas. Their approach focuses on reducing the production of the hormone IGF-1, believed to fuel both growth and, indirectly, faster ageing in large dogs.
“We live in the same environments as our dogs and share similar lifestyles,” says Ms Halioua. “By targeting IGF-1 levels, we believe we can improve overall health and potentially extend the dog’s years of vitality.”
Potential treatments on the horizon
Loyal has three drug candidates in development, two of which (Loy-001 and Loy-003) specifically target larger breeds, while Loy-002, designed for dogs over the age of 10, is closest to FDA approval. In February, the Loy-002 daily tablet received what the company calls “reasonable expectation of effectiveness” acknowledgement from US regulators, raising the possibility it may be available for prescription use later this year.
Meanwhile, the Dog Aging Project—a US-based research initiative—has been exploring the drug rapamycin since 2018, monitoring tens of thousands of volunteer dog owners and their pets in a wide-ranging study. Rapamycin has already shown potential anti-ageing effects in rodents, worms, and yeast by inhibiting mTOR, a protein that manages cellular growth and metabolism. Dr Matt Kaeberlin, a biologist at the forefront of the project, is cautiously optimistic:
“Rapamycin is one of the most well-studied interventions for extending lifespan in preclinical models,” Dr Kaeberlin says. “We’ve seen positive impacts on heart health and cancer prevention in laboratory animals, and we hope to see similar benefits for pets in real-world conditions.”
The dietary debate
Beyond drug interventions, there is broader agreement that lifestyle factors—such as diet, exercise, and stress management—play a major role in how quickly pets age. A landmark study in Labrador retrievers found that dogs fed 25 per cent fewer calories than their siblings lived a median 15 per cent longer. However, experts caution that strict calorie restriction in real-world scenarios could weaken immune responses, expose pets to illnesses, and jeopardize their overall well-being.
“A dog living in a lab may thrive on restricted calories, but the real world is different,” warns Dr Kaeberlin. “Pets face pathogens, stress, and all sorts of environmental factors. Going ‘lean-fed’ can be helpful in combating obesity, but owners should consult a vet before severely cutting calories.”
This aligns with the position of canine nutritionists such as Anna Webb, who stresses that simply feeding dogs fresh, unprocessed foods can help regulate their gut microbiomes. With research increasingly linking gut health to immunity and even cognitive function, ensuring a balanced diet might be an important—yet often overlooked—approach to increasing a pet’s quality of life.
The promise (and limits) of technology
The push to boost pet longevity has prompted a wave of gadgets and trackers. Wearable collars and activity monitors record pets’ exercise routines, while companion apps analyze dietary habits and even stool samples. For many owners, these tools are as much about peace of mind as they are about proactively extending a pet’s lifespan.
“I advocate for evidence-based approaches to improve a pet’s lifespan,” says Dr Michael Thompson, veterinarian and founder of Pets Food Safety. “That includes balanced diets, routine vet check-ups, and staying on top of dental care. In my practice, these basics often make more of a difference than expensive supplements.”
Still, cutting-edge interventions have captured the imagination of pet owners willing to spend thousands on therapies once reserved for humans. Japanese immunologist Toru Miyazaki is studying how to help cats remove dead cells more efficiently, potentially preventing kidney disease. His early findings have spawned AIM30, a special cat kibble claimed to offer kidney protection, though more definitive proof awaits further clinical data.
Ethical considerations
Critics argue that “anti-ageing” treatments for pets benefit owners more than the animals themselves, potentially prolonging the final stages of a pet’s life without preserving its quality. Ethical questions loom large: Is it fair, or even kind, to prolong an animal’s existence for the comfort of its human companions? Many scientists and veterinarians stress that longevity treatments must go hand-in-hand with improved health, a concept known as “healthspan.”
“Extending an animal’s life is only desirable if the animal continues to enjoy a good quality of life,” says Dr Thompson. “It’s crucial to ask: are we doing this for them or for us?”
For some, the question is deeply personal. Holly Brockwell, who runs a no-kill shelter for elderly and disabled cats, explains how her perspective shifted:
“When you see an animal that’s suffered its whole life only to be abandoned in old age, you want to give it a chance to experience happiness for a little longer,” she says. “I once tried chemotherapy for an ancient cat with cancer, but it came with terrible side effects. If a safer alternative to extend her healthy time had been available, I’d have done it.”
A balanced approach
As research accelerates, many experts recommend a blend of careful optimism and caution. While future breakthroughs may well help dogs and cats live longer, simpler interventions—such as regular exercise, balanced nutrition, and consistent veterinary care—remain the most cost-effective ways to enhance pets’ well-being today.
Joel Snapes, the Guardian journalist behind this deep dive, concludes that he might avoid any elaborate lengthening protocol for his young spaniel, Frankie—especially if it comes at a prohibitive cost or unknown risk.
“No longevity treatment can prevent sadness when a beloved pet eventually passes,” Snapes writes. “But if a feasible, effective option emerges that also safeguards a pet’s health and comfort, many owners might consider it. We humans, after all, have the power to decide—but the welfare of our companions should come first.”
