The end of the affair: Why do we get so grief-stricken at the loss of a pet?

When Christina McDermott was 11 years old, she had a diabetic hamster called Soda, who died. "My little brother built her a mausoleum out of chipboard," she recalls. "Unfortunately, it wasn't the sturdiest structure in the world, and one of the neighbourhood cats dug Soda up and ran off with her carcass. My mother was not best pleased."

Perhaps the growth of the UK pet bereavement industry is in part due to the structural integrity (or lack thereof) of the burial homes we gave our childhood pets. There's little need for makeshift mausoleums with the advent of "poffins" – custom-made pet coffins available in sizes ranging from "hamster/budgie" to "oversize dog". Things have certainly changed since the days when the death of a pet was a rite of passage that warranted little more than a small hole in the back garden with a tombstone made of lollipop sticks and a daisy chain for a funeral wreath.

The pet bereavement business is booming, and caters for everything from animal funerals (cremation or burial) to the transformation of ashes into memorial jewellery, and counselling for bereaved pet owners.

That said, "On the death of your dog" still isn't a section you're likely to find in your local card shop. Not surprising, perhaps, except that the growth of the pet bereavement industry suggests that the death of a pet can be a profound loss, and that the resulting grief can often be met with a lack of sympathy.

I write this as someone not known for her devotion to the animal kingdom. I accidentally starved my own guinea pig to death (my dad was right; this will happen if you don't feed them) and at the tender age of three I conducted a legendary but ill-fated experiment on my brother's terrapin involving something to do with velocity and a brick wall. So it was a shock to find myself recently rendered incoherent by the death of a dog. Why the woe? After all, she was just a dog. Well, no actually. It turns out she was much more than just a dog.

Many dog owners admit that their pooch is practically an extra child in the family, sometimes as badly behaved as the naughtiest toddler but no less adored. From James Herriot to Gerald Durrell via Lassie and Black Beauty, it's well-documented that the faithfulness of animals – and dogs especially – earns them a unique place within families, and one that holds deep, lasting significance. It follows that the loss of such an animal might therefore have serious repercussions.

Nevertheless, I didn't expect to cry when my dog-in-law died. A Weimaraner (a German hunting dog to the uninitiated), Cassie was a charming eccentric. She was eight weeks old when she came to join my husband's family and eight years old when she died. This was a dog whose presence, it must be said, sometimes invoked frustration above affection. There was nothing she could not eat. She had sampled everything from designer prescription sunglasses (twice) to a dozen eggs (shells and box included). But the discovery of an aggressive, inoperable tumour and the suddenness of Cassie's death brought to light the existence of a real and profound relationship between that dog and I, one which I had largely failed to notice while she was still alive.

Cassie was a faithful witness to many chapters of our family life. Walking the dogs in the woods behind my in-laws' house was the modern equivalent of courting, and the first year I visited at Christmas, keen to impress, I went armed with gift-wrapped doggy treats. The first time we took our newborn son to meet the family, the master of the house took the baby's blanket outside for inspection by the dogs. The theory was that the dogs would respect and recognise the baby's smell and thus accept this tiny foreigner into the fold. The gesture was as practical as it was touching, not least because that baby's first word was later a gleeful cry of "boggies!", uttered upon sight of his canine friends. Though the dogs were so large and the boy was so small as to warrant much reminding that "dogs are not for riding", they none the less formed a deep and drooling mutual love affair. More recently, seeking solace with my in-laws at a difficult juncture in our lives, walking Cassie was a daily ritual, an incantation, more for our benefit than hers. I was grateful for her exuberant distraction; it's impossible to wallow with two energetic gun dogs urging you to oblige them with a run across the fields. Cassie's untimely end served to illuminate the place she had occupied in our family's story, more poignant because it was only recognised when it was too late to be rewarded.

That's a sentiment shared by Anna Webb, who was devastated by the death of her dog, Minnie. Anna rescued Minnie from a dogs' home but felt she had betrayed her by not being there when she died. "Minnie was there for me as a grounding aspect to my life. Losing her made me realise how precious life is and that you shouldn't take it for granted," she says.

Eve Menezes Cunningham also felt guilty when her cat Lou died following a seizure. "I was completely unprepared for losing her," she says. "I held her while they put her down and when I got home I howled." Eve's previous encounters with death did little to help make sense of what she felt. "I've been to loads of funerals and have lost a lot of people. But Lou was my pet cat. I loved her unconditionally. She'd never let me down and I felt I wasn't able to do enough for her. It broke my heart that I couldn't make it all right for her." Eve was surprised by the intensity of her loss. "I remember thinking I could never have kids or get married," she says. "If the loss of a cat is such a blow, how could I cope with human loss?" Though Eve's feelings were uncharacteristically irrational and changed as her grief subsided, her experience is not unusual.

Susie Richardson found the death of her cat a bewildering experience. "If I'm honest it was quite frightening," she says. "I wasn't prepared for the intensity of my emotions. I thought I was going mad." Like Eve and Anna, Susie blamed herself. "I was so hard on myself. The what-ifs haunted me," she admits. Susie feels she might have coped better if she'd known her feelings were normal, and now volunteers with a support service for bereaved pet owners in the hope of helping others cope.

The pet bereavement Support Service ( bluecross.org.uk/web/site/AboutUs/PetBereavement) provides free emotional support to those suffering the loss of a pet. Run by the Blue Cross in conjunction with the Society for Companion Animal Studies (SCAS), the service is staffed by volunteers and funded by public donations. Use of the service has grown consistently, with the number of people calling the helpline doubling in recent years. Last year, nearly 5,000 people rang the helpline and this year's figures are already up by 200 calls compared with the same time last year. While the majority of callers are women, there is a steady increase in the number of men using the service. The Blue Cross website also allows bereaved pet owners to create a page in memory of their pet. So far this year, over 5,500 pages have been created, and during August, over 6,000 people visited those pages.

Jason Ward is a pet undertaker. His parents John and Terri Ward started their family-run business ( petfuneralservices.co.uk), based in Wales, 19 years ago, and continue to provide services to bereaved pet owners. Their pet ambulances have covered 70,000 miles in the past year, collecting deceased pets and returning ashes. The business operates around the clock and largely outside of conventional business hours. But far from being an oddity, the services that Jason provides are fast becoming the norm for bereaved pet owners. He attributes this in part to the fact that people move house more frequently, making burying animals in the garden impractical. He is regularly asked to exhume and cremate pets whose remains have been disturbed following a house move or extension build. He also connects the growth of the pet bereavement industry to the growing importance placed on pets in an increasingly fractured society. If you listen to Jason, himself a devoted dog-lover with a heartbreaking pet-loss story of his own, you'd believe that unconditional love is only to be found on four legs.

Jason likens the death of a pet to the loss of a child. He makes a compelling case. "Some people compartmentalise the relationship they have with their pets," he says. "But there's always a mother figure – not necessarily a mum or even a female – but someone in the family for whom the bond with a pet goes deeper." For them, the quotients of grief are akin to those of a bereaved parent, because the intensity of the bond and the nature of the relationship with the animal are as close to parent and child as you can get. That's not to say they equate the life of an animal with that of a child, but that the fibres that bind some people to their animals seem made of the same stuff that binds a parent to its child.

That's never truer than when a person finds their pet a reliable constant at a time when human relationships fail. Roz Leach rescued her cat, Amy, from the Cats Protection League and had her for 17 years. "One common thread that runs through many a cat lover's history is all that you experience together – divorces, deaths, illnesses, you name it. None of this means much to the cat but it does to the human," she says. When Roz left her marital home, Amy was a source of comfort and security amid uncertainty.

In Jason's experience, the most even-minded and rational pet owners are the ones hit hardest by their grief, precisely because they are unprepared for it. "You'd be surprised at the reactions we see, everything from shock to people literally collapsing under the weight of their emotions. Grief is no respecter of class or any social boundary," he says. "We see all walks of life levelled by their sense of loss."

Jason considers modern society ill-equipped for acknowledging the impact of pet bereavement. "Mention down the pub that your dog died and people change the subject, but if your granny dies they'll buy you a pint and give you a consolatory slap on the back," he says. He thinks we play down the pain of losing a pet. Also, many people don't teach their children that pets die, reducing their capacity to cope when the inevitable happens.

Christina McDermott agrees. She was 23 when the kitten she had been given at the age of 12 died of kidney failure. "He was part of the furniture of my everyday family life," she says. "I cried my eyes out. It was like a cornerstone of my teenage years had gone."

Losing a childhood pet seems as defining a moment as the first taste of teenage heartbreak. Lynley Oram was 16 when her beagle was killed. "She was like the youngest sibling in the family," she recalls. "It seemed wrong to get another dog, and I've never owned another pet. It's such a commitment to love something like that. What if it happened again?"

For others, the loss of a pet awakens latent empathies. When Helen Kaut-White's cat vanished, she was devastated by not knowing what had happened to him. For closure, she buried the cat's brush in the garden at her granny's suggestion. "I was surprised by her understanding," she says. "She's not a cat person but she told me how hard it was for her family when her brother disappeared during the Second World War."

Carrie Dunn was terrified of dogs for almost 25 years, having been bitten on the face as a child. She was understandably anxious about meeting her boyfriend's German shepherd, Conner, but a bond slowly grew, and she was devastated when Conner developed a fatal tumour. "I knew I'd be upset when he died but I didn't realise how much," she says. "I couldn't stop bawling and stayed in bed crying. It felt really wrong to be so upset when he wasn't actually my dog, but David and the vet both pointed out that of course he was my dog too, because I loved him so much and he loved me."

Mary Leigh runs a pet clotheswear company, equafleece.co.uk, and the retired greyhound she rescued became its principal model for several years. "Josh didn't like to be left so he became an integral part of my working life," she says. "When he died he'd been with me for the best part of eight years – my shadow, my constant companion." Mary encouraged her children to see the dead dog. "I think that helps normalise the experience of losing a pet," she says. "The more you can prepare a child for the reality that all things die, the more you're preparing them for life."

That's a sentiment echoed by John Grogan, the American journalist who penned a eulogy for his dog and immortalised him in the book-turned-film Marley & Me. "A person can learn a lot from a dog, even a loopy one like ours," he wrote. "Marley taught me about living each day with unbridled exuberance and joy, about seizing the moment and following your heart. He taught me to appreciate the simple things – a walk in the woods, a fresh snowfall, a nap in a shaft of winter sunlight. And as he grew old and achy, he taught me about optimism in the face of adversity. Mostly, he taught me about friendship and selflessness and, above all else, unwavering loyalty."

To contact the Pet Bereavement Support Service call 0800 096 6606 or e-mail pbssmail@bluecross.org.uk. Call 01993 825539 for information about becoming a volunteer