​You came as part of a team with your brother Monty, nine week old border collies. I only wanted one puppy, but when I visited the strange and surreal farm (with a derelict badger under a piece of tarpaulin...raccoons in the garden) hidden deep in a Devon valley where you were born, there were only two pups left from the litter of eight, so what was I supposed to do? The boy pup was confident and friendly, the obvious choice; you were nervous and wary, skulking in the corner with a huge scab on your fluffy back and a pink map of Italy making your nose look lopsided, and you were insanely pretty. I didn't quite buy one, get one free, but I negotiated a slight discount mainly to convince myself that what I was doing was totally sensible, and you both came home with me.

The scab on your back turned out to be a particularly bad flea allergy, and the vet said your fur might never recover, but after treatment (watching scores of fat fleas falling off beforemy eyes on to the pale wood floor) you were good as new in a couple of weeks, and even prettier - a tricolour with huge amber eyes. Oh such eyes...and the map of Italy slowly disappeared from your nose, and you were perfect.

You were always the nervy one, the worried one. My silly Lily. Monty would come out eagerly to assess any visitors, ready to be friendly, but you would bark angrily from under the kitchen table to convince him they should all be bitten and sent running for their lives, and it worked. You told him that joggers were a threat and he dutifully nipped them, to my complete mortification. You were never apart, the terrible twins, team-destroyers of the new wooden kitchen (in spite of the clove oil everyone swore by to prevent such wanton fun).

But once you had grown up, you left behind all things doggy and concentrated on your career as Monty's shadow. There were maybe a dozen occasions in your whole life where you felt "off duty" enough to chase a ball or chew a stick...having first checked that Monty was busy with his own. And seeing you actually play...running happily with your ears up and your beautiful flag of a tail flying high...it made me emotional every time. Poor Lily, too worried to be a dog most of the time. Monty played with balls and chased sticks, and you watched him fixedly, poised for action. Your job was to make sure no harm befell him and you never took your eyes off him for eleven years.

Unless...you were cuddled up with me at home. The children used to say that it wasn't clear where Lily ended and I began. You were my other half, my devoted girl, and I only had to sigh for you to appear at my elbow and nudge me into reassuring you...neediest dog in the world, awash with love and concern and tireless in the giving and taking of it. You scuttled through life and never seemed tired or lazy. Until last year, when you slowed a little and didn't follow me upstairs every time. I put it down to being older, because you still became a crazed screeching mad thing when we were getting ready to go out for walks, and you appeared fine...

And then you had a small seizure one day. You recovered quickly and sat quietly on the sofa with me for the rest of the evening. I watched you closely the next day and you were almost normal....almost. But I had a bad feeling, and then you just sat down suddenly on the path, with the saddest face, as though you felt you were letting me down, and I carried you part way back to the car and phoned the vet. Blood tests revealed the type of anaemia that follows an internal bleed (which explained the seizure, low blood pressure) but the vet could feel nothing obviously amiss and a second blood test was normal. I relaxed a little...but the words "possible liver tumour" had been said and they were in my mind now. Irrevocably.

So one morning a month later when you tried to stand up and fell down again, I looked at your gums straight away and saw that they were already white. It was really happening. The tumour we had feared was there had ruptured, and you were bleeding out internally, and there was nothing whatsoever that could be done. I knew this from a friend whose beloved dog had the same problem. I was alone at home and the kindly vet was a thirty minute drive away. I agonised about what to do. You were so nervous and anxious about going there anyway, and I was terrified you would die on the way without my arms around you. So we just sat for several hours, and I never left your side; and you moved from place to place a couple of times and panted a lot, but I don't think you had much discomfort. At one point I thought I would take you to the vet, so they could ease you swiftly through this process of dying, but you cried out when I lifted you, and I just held you on my lap after that, with your head tucked under my chin, and talked to you constantly. Over and over again I told you what a good dog you were and how much I loved you; and your heart raced and raced until...it just stopped. I actually felt it stop under my hand. And you breathed out, my lovely Lily, and died so quietly.

Monty had been silent and watchful all morning, and he got up on the sofa and lay with his head on your back. I cried for an hour, and then had to call the children one by one and tell them.

It's been five months and it's still awful. The house is quiet, the car is quiet, and Monty and I sit in companionable silence and miss how you filled all the gaps in the conversations with your fuss and nonsense and outpouring of love. We miss you on every walk,and grown men cried when I had to tell them you had gone so suddenly. You came back to me in a dream, just once, and did your customary thing of rushing up and shoving your head insistently under my arm. And I knew in the dream that you had died and that this was a miracle. And I cried out, "Lily oh my Lily," like Jenny Agutter at the end of the Railway Children...and I know that was you, saying goodbye, all is well. Thank you, darling girl.