This isn’t sentiment. This is neuroscience.
If you’ve lost a pet and found yourself surprised — genuinely caught off guard — by how devastated you feel, you’re not alone. And you’re not overreacting. Here’s the science behind why losing a pet hurts.
Most of us grew up in a culture that treats grief over a pet as something smaller than other grief. Something to move through quickly. Something that doesn’t quite warrant the same acknowledgment as losing a person. You get a few sympathetic texts, maybe a day where people tread softly around you, and then the world moves on.
But your nervous system doesn’t get that memo.
What you’re feeling after losing a pet is not a lesser version of grief. Science — real, peer-reviewed, published-in-major-journals science — is now telling us clearly what many pet owners have always known in their bones: this is the real thing. This is genuine loss, processed by a brain that formed a genuine bond, and it deserves to be treated that way.
Here’s what the research actually says.
The Study That Changed the Conversation
In January 2026, a landmark study led by researcher Philip Hyland of Maynooth University was published in the journal PLOS One. It is the most rigorous examination of pet grief ever conducted, and its findings are difficult to argue with.
Researchers surveyed 975 adults in the United Kingdom, asking which types of losses they had experienced, which loss they found most distressing, and whether they had symptoms of prolonged grief disorder — a condition involving twelve months or longer of debilitating grief. Rockanimal
One third of respondents had experienced the death of a beloved pet, and almost all of those people had also experienced the death of a human. Among them, 21% chose the death of their pet as the most distressing bereavement they had ever experienced. Aplb
Read that again. Among people who had lost both a pet and a human loved one, one in five said the pet loss was harder.
Around 7.5% of people who had lost pets met the clinical criteria for prolonged grief disorder — comparable to rates following many human deaths, including the loss of a close friend or grandparent. Petworks
Perhaps most significantly, the research found no measurable differences in how prolonged grief disorder symptoms manifest, whether the loss involves a person or a pet. The grief operates identically. The brain doesn’t distinguish. The pain is the same kind of pain. Petworks
Why Your Brain Bonds With a Pet the Way It Does
To understand why the loss hurts this much, you have to understand what the relationship was actually doing — neurologically — while it was happening.
When you interact with your pet — making eye contact, petting them, simply being in the same room — your brain releases oxytocin. Oxytocin is the same bonding hormone involved in forming relationships with human family members, and eye contact with a dog triggers its release in both the human and the animal. Sage Journals
This isn’t metaphorical. It’s measurable chemistry. Every morning they greeted you, every evening they settled beside you, every time they sought you out — your brain was being chemically reinforced to bond with them more deeply. Day after day, year after year.
A 2014 study from Massachusetts General Hospital and Harvard Medical School used fMRI brain imaging to examine what happens in a mother’s brain when she looks at photos of her own child versus photos of her own dog. Researchers found a common network of brain regions involved in emotion, reward, affiliation, and social cognition activated by both — and mothers rated images of their child and dog as producing similar levels of emotional arousal and pleasantness. Love, Baxter
The brain, in other words, processes the love for a pet and the love for a child through many of the same neural pathways. This is not a figure of speech. It is a finding from brain imaging research conducted at one of the most respected medical institutions in the world.
When a pet becomes part of your daily emotional regulation system — a source of comfort, routine, and unconditional presence — they become woven into your neurological life. When they die, your brain and body must recalibrate without the living presence of that bond. The synchronized rhythms of affection, comfort, and shared presence are suddenly severed. Routledge
What you feel in those first days and weeks isn’t simply sadness. It is your entire nervous system adjusting to an absence it was chemically structured to resist.
The Routine Was the Relationship
There’s another dimension to pet grief that science helps explain — one that catches many people off guard.
With human relationships, love exists alongside complexity. History, conflict, ambivalence, distance, unresolved things. With a pet, the relationship is free from the social complexities, conflicts, and ambivalence that often complicate human dynamics. A pet provides pure, unconditional acceptance, and their daily routine dictates the rhythm of our lives. harvard
That routine — the feeding, the walks, the particular sounds of their day, the way they tracked your movements through the house — was not just habit. It was the architecture of your relationship made physical. It was how love expressed itself concretely every single day.
When the routine stops, the absence is everywhere. When a pet enters decline or dies, that daily rhythm fractures. You reach for the leash that doesn’t need reaching for. You move quietly out of habit so you don’t wake them. You buy their food before you remember. These are not small moments. They are the places where the loss lives, and they are constant. harvard
The Grief Nobody Acknowledges
Here is the part that makes it harder than it needs to be.
Pet loss is frequently stigmatized, minimized, or dismissed, resulting in limited social support and cultural validation for those who are mourning. Researchers call this disenfranchised grief — grief that a person experiences when they suffer a loss that is not openly acknowledged, socially sanctioned, or publicly mourned. Wikipedia
Research focusing on North American pet owners shows that roughly one third of people experience disenfranchised grief after losing a pet. Each day in the United States alone, over 38,000 people lose a pet. Lapoflove
That’s 38,000 people a day carrying a grief that their workplace, their social circle, and sometimes even their own internal voice tells them isn’t quite legitimate.
When loss is unacknowledged, discounted, or minimized, people experience isolation and disconnection in their closest relationships. They may develop guilt and shame over the grief they feel when they find themselves unsupported — further deepening the isolation and making healthy grieving harder to reach. DVM360
The science is not ambiguous here. The grief is real. The bond was real. The loss is real. And the cultural failure to acknowledge it doesn’t reduce the pain — it compounds it.
What This Means For You Right Now
If you are in the middle of this grief and any part of you has been wondering whether you’re handling it correctly, whether it’s appropriate to still feel this bad, whether you should be further along by now — the research has a clear answer.
A University of Michigan study of 174 adults who had lost pets found that 85.7% experienced at least one symptom of grief immediately following the loss. Symptoms decreased to 35.1% at six months and 22.4% at one year — and the severity and length of those symptoms was significantly correlated with the strength of the bond the person had formed with their pet. Phys.org
Which means the more you loved them, the longer this takes. That is not weakness. That is the direct and measurable consequence of a deep attachment. The grief is proportionate to the love. It cannot be otherwise.
People experiencing deep and prolonged grief over losing a pet should consider seeking support, and should also be aware of potential physical effects including fatigue, headaches, and dizziness — all documented physical responses to grief that deserve the same attention you would give any other health concern. Rockanimal
You are not alone in this. The science says so clearly. And the science also says that what you had with your pet — the bond, the routine, the daily chemistry of loving and being loved — was something real and significant and worth grieving fully.
Honoring What Was Real
One thing that research on grief consistently finds is that people heal more completely when they are given permission to honor the loss rather than minimize it. When the grief is acknowledged, named, and given a place — rather than pushed aside and moved past — the path through it is healthier and more complete.
That means letting yourself grieve without apology. Talking about them. Saying their name. Telling their stories. Creating something in their memory that holds who they actually were — not just what they looked like, but the specific, irreplaceable personality of the animal that shaped your days.
[LINK: How to Create a Pet Memorial Space at Home]
[LINK: 10 Ways to Honor a Pet Who Has Passed]
And when you are ready — in your own time, on your own terms — [LINK: Everhere.us] we are here to help you capture exactly who they were, before the details that only you know begin to blur.
The science says the bond was real. Honor it like it was.