What Your Pet Is Actually Doing to Your Brain

Picture the moment: you have just walked through the front door of your HDB flat after a twelve-hour day. The commute was standing-room on the MRT. Your inbox still has forty-three unread messages. Somewhere behind your eyes is the specific dull pressure that Singaporeans recognise as the chronic kind of tired — not the tiredness that sleep fixes, but the kind that has been compounding since the last long weekend. And then your cat jumps up onto the bench beside you, leans against your arm, and starts to purr.

Something happens. You know it happens — you can feel it. But what, exactly? What is the biology of that moment? What is your brain doing, and why does a warm animal make it do that? These are questions scientists have been asking seriously for about forty years, and in the last decade they have started to get answers precise enough to cite in peer-reviewed journals. The answers are, if anything, more interesting than the feeling.

This is the story of what your pet is actually doing to your brain — and why the research lands differently when you read it in Singapore, a city that has one of the most demanding work cultures in the developed world, a loneliness problem it is only beginning to measure, and a fast-ageing population that is about to need every wellness tool it can find.

The city's particular kind of stress

To understand what pets are doing for Singaporeans, you have to understand what Singapore is doing to them. The data here is blunt. According to Ministry of Manpower figures, the average Singaporean works 44.5 hours a week — among the highest in the developed world. A 2024 Wellness at Work report found that 61 per cent of employees are struggling with burnout. Employment Hero's research found the figure climbs to 68 per cent among Gen Z workers. Burnout, anxiety and stress cost the Singapore economy an estimated S$15.7 billion annually in lost productivity.

The mental health picture is consistent with the burnout data. The Institute of Mental Health's Mind Matters 2 study — the most comprehensive national mental health survey Singapore has conducted, covering 4,195 citizens and permanent residents surveyed between 2022 and February 2024 — found that 25.5 per cent of young adults aged 18 to 29 reported poor mental health, the highest rate of any age group measured. Young women in that bracket registered 31.7 per cent — more than double the national average. The second Singapore Mental Health Study, conducted in 2016, found that the lifetime prevalence of any mood, anxiety or alcohol use disorder had already risen to 13.9 per cent, up from 12.0 per cent in the 2010 study.

Sitting alongside the burnout and mental health data is a loneliness story that Singapore has been slower to talk about but that researchers are now measuring carefully. A 2023 poll by the Institute of Policy Studies, covering 2,356 Singaporeans and permanent residents, found that young adults aged 21 to 34 reported the highest loneliness scores of any age group measured — higher than the elderly. More than half of respondents in that age group said they felt anxious about talking to people in person and found it easier to communicate online. A city of five-and-a-half million people, and the loneliest residents are the young adults who fill its offices.

This is the backdrop. This is what researchers mean when they talk about Singapore's "particular stressors" in the pet-and-mental-health literature. And this is the context in which the science of what pets do to the brain stops being academic and starts being practically urgent.

What the Singapore data actually says

The most direct Singapore-specific evidence comes from a study conducted at the Yong Loo Lin School of Medicine and the Saw Swee Hock School of Public Health at the National University of Singapore during the COVID-19 circuit breaker of 2020 — exactly the kind of high-stress, high-isolation environment that forces the question of what, if anything, a pet actually does for your wellbeing.

The researchers, led by Joel Shi Quan Tan, recruited 534 Singapore residents aged 21 to 64 during the circuit breaker period between May and July 2020 — when the city was in lockdown, movement was restricted, and the psychological toll of enforced isolation was acute. They compared pet owners to non-pet owners across a battery of validated mental health measures. The results were striking. Pet owners scored 9.66 points higher on emotional wellbeing, 8.29 points higher on energy levels, and 11.2 points higher on social functioning — all statistically significant differences at p-values below 0.001. Dog owners also reported 31.8 more minutes per week of mild-intensity physical activity.

The researchers noted an important nuance: the benefits were strongest in pet owners who identified as the primary caregiver and who scored higher on pet attachment measures. This is a thread that runs through the wider literature — the quality and depth of the relationship matters, not just the presence of an animal in the home. A pet is not a passive appliance for dispensing wellness; it is a relationship, and it is the relationship that does the work.

The oxytocin loop: two species, one bond

The most extraordinary piece of science in this field is also one of the most elegant. In 2015, a team led by Miho Nagasawa at Azabu University in Japan published a study in the journal Science that traced the precise neurochemical mechanism by which gazing at your dog makes you feel good. The team recruited thirty dog-owner pairs and measured urinary oxytocin — the neuropeptide associated with social bonding, trust and love — before and after a thirty-minute free-interaction session. Dogs whose owners spent more time in mutual gaze showed the largest increases in oxytocin. And here is what makes the study remarkable: the oxytocin rose in both the human and the dog, in a feedback loop that is almost identical to the one that operates between a mother and an infant.

The study did not find the same loop in wolves and their handlers, which led Nagasawa and colleagues to conclude that the oxytocin-gaze bond is a product of domestication — something dogs evolved to trigger in humans, over tens of thousands of years of co-existence, as a mechanism for cementing the partnership. When you catch your dog looking at you across a room, you are not imagining a connection. You are experiencing a biochemical event with deep evolutionary roots.

Ten minutes. That is all it takes.

If the oxytocin-gaze finding is the most elegant result in the field, the most practically useful finding for a time-poor Singaporean might be what Patricia Pendry and Jaymie Vandagriff at Washington State University found in 2019. Their randomised controlled trial recruited 249 undergraduate students and assigned them to one of four conditions: hands-on petting of dogs and cats, observing others pet animals, viewing images of the same animals, or a waitlist control group. Then they measured salivary cortisol — the hormone most closely associated with the physiological stress response.

Just ten minutes of hands-on petting produced a significant reduction in cortisol compared to all three control conditions. Not an hour. Not a structured therapy session. Ten minutes. It was also the first study to demonstrate cortisol reductions from animal contact in a real-life setting rather than a laboratory — and the effect held whether the animal being petted was a dog or a cat. The researchers noted that students who merely watched others pet animals, or looked at photos, showed no significant cortisol reduction. The physical contact was what mattered.

For context: a ten-minute petting session is shorter than most MRT commutes. It is shorter than a coffee queue at a kiosk during the morning rush. The physiological case for owning a pet is not asking you to reorganise your life. It is pointing out that something you are probably already doing is working on your hypothalamic-pituitary-adrenal axis in measurable, reproducible ways.

The heart of the matter

The cortisol reduction does not stay neatly in the brain. It moves downstream. Lower cortisol means lower sympathetic nervous system activation, which means lower blood pressure, lower resting heart rate, and, over time, measurable differences in cardiovascular risk. The American Heart Association published a review in Circulation in 2013 noting that multiple studies had found beneficial effects from pet ownership, including lower blood pressure, more favourable lipid profiles, and improved autonomic tone.

The most powerful dataset in this space comes from a 2017 Uppsala University study, led by Tove Fall and Mwenya Mubanga, which drew on Swedish national registers covering 3.4 million people with up to twelve years of follow-up. The team found that dog ownership was associated with a 33 per cent lower risk of death for people living alone, and an 11 per cent lower risk of cardiovascular disease. For single-person households — the demographic group that is most rapidly expanding in Singapore — those numbers are not small. A 2019 study in Circulation: Cardiovascular Quality and Outcomes, drawing on Swedish data for 336,000 post-heart-attack patients, found that dog owners had a 31 per cent reduced risk of dying from cardiovascular causes after the event, and a 65 per cent reduced risk of dying after a heart attack compared to non-dog-owners.

The causal story here is probably multi-factorial: regular walking, increased physical activity, reduced social isolation, lower chronic stress, lower blood pressure. Dog owners do not live longer because of magic; they live longer because their dogs give them a hundred small reasons to get off the couch, stay connected to their neighbours, and keep their cortisol from spending decades elevated. But the outcome is the outcome, and the size of the effect is large enough that cardiologists take the data seriously.

Cats, small pets, and the question of species

Most of the dramatic cardiovascular findings are about dogs. The dog-and-gaze literature, the dog-and-walking literature, the dog-and-longevity literature — these are predominantly canine stories, partly because dogs are easiest to study (they go places with their owners) and partly because the oxytocin-gaze mechanism is specifically canine. So where does that leave the estimated 94,000 or more cats living in Singapore flats, the hamsters in their cages on study desks, the rabbits that became Singapore's third most popular pet during the pandemic years?

The evidence for cats and small pets is more mixed, and it is important to say that honestly. The 2019 Washington State University cortisol study found the ten-minute effect held for cats as well as dogs — physical contact with either species produced the reduction. A 2023 Morning Consult poll of 2,200 adults found that 86 per cent of pet owners — equally among dog and cat owners — reported positive mental health effects from their animals, with the most commonly cited benefits being reduced stress, emotional support, and companionship. A 2025 systematic review and meta-analysis in Annals of General Psychiatry found that overall pet ownership was not significantly associated with higher rates of depression, though it noted the evidence base remains heterogeneous and subject to confounding.

Cat ownership, specifically, appears to reduce the subjective experience of stress and loneliness for many owners, even if the measurable physiological effect is smaller than for dogs. The purr is not nothing. The feel of a cat settling its weight against your leg has a physical dimension that is different from scrolling through your phone. And for the many Singaporeans who live in HDB flats — where, until September 2024, cats were illegal but where they lived anyway in their tens of thousands — the relationship between cat and owner clearly meant something, or people would not have taken the regulatory risk.

For small pets — hamsters, rabbits, guinea pigs — the honest position is that the research is thinner. What exists suggests that the mechanisms of care, responsibility, and routine that any pet provides may be as important as species-specific effects. A 2021 qualitative study in the journal Anthrozoös found that pet owners across species frequently described their animals in terms of the reason they get up in the morning, the anchor in a difficult period, the constant when everything else is uncertain. A hamster does not produce the oxytocin-gaze feedback loop. But having something that depends on you, that notices when you come home, that gives you a reason to maintain a routine — these appear to be beneficial for mental health independent of species.

The social glue nobody talks about

One of the more counterintuitive findings in the pet-and-wellbeing literature is that pets do not just affect your internal state — they change your relationship with the people around you. A 2025 study published in PLOS ONE by Itaru Ishiguro and colleagues at Sagamihara City near Tokyo examined 377 participants using generalised structural equation modelling to understand how dog ownership affected social capital and sense of community. The key finding: dog ownership was significantly associated with what the researchers called "anchored personal relationships" — the recurring, place-based interactions with neighbours and other regulars that form the substrate of community life. The regression coefficient was b = 1.13 (95% CI: 0.59–1.67, p < .001). More strikingly, it was those anchored relationships, not friendships or casual interactions, that mediated the effect of dog ownership on sense of community.

In plain English: dogs give you neighbours. They give you the same person at the park every morning. They give you the other walker whose name you know and whose dog your dog loves. These recurring, place-anchored interactions are exactly the kind of social infrastructure that research on loneliness identifies as protective — and exactly the kind that urban density, long working hours and phone-mediated socialising are eroding in Singapore.

For Singapore, where the 2023 IPS poll found that adults aged 21 to 34 report the highest loneliness scores of any age group — including the elderly — and where more than half of young adults say they find it easier to communicate online than in person, this mechanism is not a small thing. The dog is not just lowering your cortisol in private. It is pulling you outside, into contact with your neighbourhood, and making you a more socially embedded human being.

The ageing question

Singapore is ageing faster than almost any developed country in the world. By 2030, one in four residents will be aged 65 or above. The number of single-person households for those aged 65 and above more than doubled between 2014 and 2024, rising from 42,100 to 87,200 households. Research from Singapore's Centre for Research on Successful Ageing has found that about 4 in 5 older adults report feeling socially isolated despite living with their families — a reminder that physical proximity and genuine connection are not the same thing. A study in BMC Geriatrics found that living alone was associated with a hazard ratio of 1.66 for mortality among older adults in Singapore, independent of health and other variables.

Animal-assisted activities are already part of the response to elderly isolation in Singapore, if not yet at scale. SOSD's Healing Paws programme, launched in January 2014, brings volunteers and their dogs to elderly homes, children's homes and hospices, including Ren Ci Nursing Home, Thye Hua Kwan and HCA Oasis Gracehaven. The programme does not claim clinical outcomes — it is structured as animal-assisted activities, not therapy — but it operates on the same physiological principles: physical contact, novelty, positive social interaction, a reason to engage.

For elderly Singaporeans who own their own pets, the picture is more complex but broadly positive. The Swedish cardiovascular data is most protective in single-person households — precisely the demographic that is growing fastest in Singapore's ageing population. Pets create routine, which is protective for elderly mental health. They create gentle physical activity, which is protective for mobility. They create ongoing social interaction — with the animal itself, and with the community of other owners that forms around places like the park and the groomer.

Healing Paws and the formal side of the bond

Beyond individual ownership, Singapore has a small but growing animal-assisted therapy and activities sector. The Centre for Human Animal Connection (CHAC) conducts animal-assisted interaction programmes in special-needs schools, nursing homes and health institutions. Cat-Assisted Therapy Singapore (CATS), operating under NeuroDiverCity, focuses on interactions with cats for neurodiverse individuals. A 2015 pilot study published via ResearchGate and assessed in a Singaporean clinical context found that with stringent candidate selection and sound safety measures, the future for animal-assisted therapy in Singapore was "promising."

These programmes draw on a well-developed body of international evidence. Guinea pigs have been shown to reduce anxiety in children with autism spectrum disorder in school settings. Canine-assisted interventions at universities in Thailand produced measurable stress reductions in students — consistent with the Washington State University findings. The mechanism is consistent across contexts and species: direct, positive, physical interaction with an animal produces a measurable shift in the human autonomic nervous system.

A city that turned to pets during the hard months

Singapore's own pandemic data captures something important about what people reach for under acute stress. The Society for the Prevention of Cruelty to Animals reported that foster applications rose tenfold during the 2020 circuit breaker — from 10 to 15 per month before the lockdown to 120 to 150 per month during it. More broadly, the COVID-19 period saw a surge in pet acquisition across the island, with poodle prices reportedly inflating from S$2,000–3,000 to S$8,000 as demand outpaced supply.

Not every circuit-breaker pet story had a happy ending — animal welfare groups documented a subsequent 30 per cent rise in abandonments as workplaces reopened, which is a real and documented harm that comes from impulse rather than considered ownership. But the raw act of tens of thousands of Singaporeans reaching for animals during their most stressful period in a generation is data of its own kind. People knew, before any of the studies confirmed it, that pets helped.

The science is now catching up to the intuition. It is saying: yes, the thing you felt is real. It has a name — oxytocin. It has a mechanism — the hypothalamic-pituitary-adrenal axis. It has a dose — ten minutes. And it has an effect size that is large enough to show up in a cohort of 3.4 million Swedes followed for twelve years.

What this means — with caveats

None of this is a prescription. The science of pets and wellbeing is real, but it is also genuinely complex, and it would be dishonest not to say so. Most studies in this field are observational, which means they can identify associations but cannot cleanly establish that owning a pet caused better mental health outcomes rather than that healthier, less isolated people are more likely to own pets in the first place. The largest longitudinal UK study on the topic, published in 2024, found no significant association between pet ownership and improvements in depression, anxiety or loneliness during the COVID period — a finding that sits in productive tension with the Singapore and Swedish data.

Cat ownership, specifically, has been associated in some studies with higher rates of depression, though the 2025 meta-analysis in Annals of General Psychiatry found that the overall association between pet ownership and depression was not significant. The research on small pets — hamsters, rabbits, fish — is thinner still. And for some people, the financial burden, time commitment, housing constraints and emotional weight of pet loss are real costs that can outweigh benefits. The decision to get a pet is a serious one, and no study on oxytocin should substitute for genuine self-assessment about readiness and capacity.

What the strongest evidence supports is more precise than "pets make you happy." It is this: the act of caring for and physically interacting with a companion animal triggers a series of well-mapped neurobiological responses — reduced cortisol, elevated oxytocin, dampened sympathetic nervous system activity — that have downstream effects on blood pressure, social behaviour, physical activity, and, in large prospective cohorts, mortality. The relationship quality matters. The attachment depth matters. The consistency matters. Pets are not passive wellness tools; they are relationships, and relationships require investment, attention and honesty about what you can genuinely offer.

But for the people who are in those relationships — the hundreds of thousands of Singaporeans sharing their flats with dogs, cats, hamsters, rabbits, and everything in between — the science is now in a position to tell them something they probably already suspected: the warmth they feel when their animal comes to find them after a hard day is not a soft, unverifiable feeling. It is cortisol dropping. It is oxytocin rising. It is two species, tens of thousands of years of shared history, and a neurochemical conversation that both sides are having at once.

In one of the most high-pressure, high-density, high-achievement cities in the world, that conversation — quiet, unhurried, conducted without words — might be one of the most important ones happening.

By the numbers