Today I found one of Sukie's whiskers under a stair-rod and I wept all over again, even though she's been gone three months.' That was the line that moved me most in a letter I received in my postbag, from a woman who'd lost her beloved cat.
And after I'd published her letter in my agony aunt column, I had a staggering response from readers who felt exactly the same. Indeed, so many heartfelt letters arrived - 'I cannot look at where Buster left his scratch marks on the door, and yet I cannot bear to paint them over'; 'I am writing this in my greenhouse, shaking with sobs - I could not let my wife see me like this, but truly Sheba was the only living thing I have ever truly loved and who loved me' - that I wrote Goodbye Dear Friend, Coming To Terms With The Loss Of A Pet, reissued this month.
People often sneer at those who mourn when their pets die, saying that the grief can't possibly be as bad as it is over a human being. They think that 'getting another one' will put everyone thing right.
Or they claim that all this sentimentality about pets, and the increase in the number of pet crematoria and pet bereavement helplines is some kind of mawkish, new and over-sentimental 'American' or 'Diana-like' phenomenon. But people have always felt devastating grief when their pets die.
Byron's inscription on the headstone to his dog, Boatswain, illustrates the emotions perfectly. 'Near this spot are deposited the remains of one who possessed Beauty without Vanity, Strength without Insolence, Courage without Ferocity, and all the Virtues of Man without his Vices.
This Praise, which would be unmeaning Flattery if inscribed over human ashes, is but a just tribute to the Memory of Boatswain, a dog.'
You can't really understand the grief people feel over a pet's death without understanding their relationship with animals in the first place.
Pets may be substitute children, completely dependent on their owners for their well-being and offering unconditional love. I suspect this was true in the case of actress Calista Flockhart who understandably went to pieces when her dog, Webster, died. (Her boyfriend, Harrison Ford, was, apparently, so unsympathetic about her grief, being of the 'Why not get another one?' brigade, that they even split up temporarily.)
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And artist Tracey Emin is unashamed in admitting that her cat, Docket, is a substitute child. 'Docket is not just a pet to me. Without sounding too corny, he is really like my baby,' she has written. 'The reason why I love him so much is because of all the love I have invested into him. 'To some people, a cat is just a cat. It miaows, it has to be fed and it has a tail. But for me, cats are small animals which occupy a massive amount of my mind - especially Docket, who I live with.
'If I'm honest, I realise that I plan a lot of my life around my cat. And by this, I don't mean small things, I mean where I live, who I live with and my future plans. Should I move to the country? Should I live by the sea?
Every large-scale decision that I make involves Docket.' An animal's love is always wholehearted. It's never grouchy in the mornings, or irritable in the car if you lose your way. It never criticises you when you're down or says things such as: 'I think you are wrong'.
It's always there, wordless, faithful, ever available with a lick and a warm furry body to snuggle up to when you feel down. A dog can act, too, as a protector, barking when strangers come to the house. You feel safe when it's around. And the grief one feels about the death of a pet can be compounded because the grief can feel so lonely.
When a close relative dies there are plenty of other bereaved people around to comfort you, because the dead person had close relationships with other people in his or her life. But often the only person who knew your animal really well, was you, the owner. Grief over an animal can be tremendously isolating.
Why is it that people think that because pets can't talk, are smaller than us and don't last very long - we animal lovers have to suffer bereavement after bereavement if we have animals in our lives - that we should get over their deaths so quickly?
I've had letters from people who are still grieving for animals years and years after their death, and there are pet cemeteries where couples often go up week after week and year after year to put flowers on their dead pet's graves.
In Dogs Today magazine, which features a memorial column for pets, one obituary reads: 'Shayne: I can't believe it's two years since you left me, but in my heart you live on for ever. We had 18 wonderful years together. You helped me grow up and taught me so much with your love. We will be together soon, wee man. Wait for me, son, love Mum xxxxxx'
Even rats have their day. This was to Loot, who died aged three. 'A shy gentleman who loved his food. Put to sleep because of cancer. Now reunited with brother Nailer. Thank you for keeping me company. I shall not forget you.' An animal may be only an animal, but it is, like a human being, a form of life - even if it has four legs or a beak, fur or feathers, and no language to say 'I love you'. And yet to adore something so fundamentally different to ourselves is often seen as rather weird.
The English ladies in Naples who feed the stray cats; the widow who leaves all her money to Battersea Dogs' Home; the man who kills himself when his pet dies; the tourist who spends £6,000 bringing a stray dog back home from Spain - they're all thought to be very sad and touching, but completely bonkers.
Sometimes I wonder why it never occurs to people who don't really love animals that it is they who are the crazy ones.
At Salisbury Cathedral, the former Bishop, the Rt Rev John Austin Baker, would hold regular services for animal blessings.
'Some say it's very sentimental and that there's no point in blessing an animal,' he said. 'But the beauty of the life and character of an animal is a blessing in itself. Perhaps we should get blessed by animals rather than the other way round.' Each of us who has loved, and been loved, by an animal can't fail to feel blessed. It's small wonder we grieve for them when they die.
Farewell, old friend: The pain of losing a pet | Mail Online