There are many tough things that go with bringing a strange dog home. Who is he? Where has he been? What's his or her her history? What sort of baggage might he bring with him? What's he going to do to the carpets and furniture?

It's impossible to know exactly what we are buying into when re-homing an older dog, whether he's coming from the RSPCA, a pound, or simply a former neighbour. When I once enquired about the medical history of a Border Collie I was thinking of taking in I told all concerned that it wouldn't put me off, just that I needed to know. The RSPCA said she was a seven years old bitch, and the vet told me that he was a six years old dog. At least the owners knew – he was a seven and a half years old male – but they were all clear that he had no significant medical history beyond annual vaccination jabs.

A week into our relationship he had a truly massive fit - at the time I thought he was dying on me - and continued them regularly for the next ten years, until old-age caught up with him and cured him of them. Two years after he came to us, his former owners casually said, in a reply to an update I'd sent them, that they hoped he wasn't having those awful fits any more. When I had him checked at the vets, and accessed his history for myself, it turned out he'd had them all his life, and had also sustained a major impaling injury as a pup, with consequent major surgery.

Another time we took first one, and then the other of two Rottweiler bitches from a family that were expecting twin babies and felt they wouldn't be able to cope with the dogs as well. No one mentioned that the dogs fought each other in the manner of a couple of territorially pissy Tyrannosaurus Rex. They seriously compromised the balance of the pack till we got them settled down, not to mention the vet bills for shredded ears and holes torn in their necks en route.

One Collie X Lab dog spent his first eleven months with us leaping from the sofa to the TV and back, refusing to eat with the others, barking incessantly, and apparently pointlessly, and running off at every opportunity. He's one of my favourite ever dogs now, bright, communicative, and responsive.

Harvey, a Collie X Lurcher, didn't wag his tail for the first two years we knew him, and wouldn't come within a mile of anyone holding anything at all, whether it was a broom or a mug of tea. When the dog warden picked him up Harvey had no fur on his back due to a flea-allergic reaction, ears full of mites, eyes closed and leaking pus, and was practically see-through, he was so thin. He was the only dog I've ever known who knew how to break ice from a pond to get a drink.

We've had dogs that hate all other dogs on sight. Dogs that lost first one eye and then the other. Dogs that eat car interiors – or the couch. Dogs that sound the alarm for spiders, or leaves blowing in a draft. Dogs that see food as a power base they will fight to the death over. Dogs that shit on the bed - OUR bed. Dogs that wake up on the couch, stretch languidly, pee where they were lying and then move to the other end of the couch where it's nice and dry. Dogs that cheerfully jump from first floor windows. Dogs that vomit and then eat it, and dogs that eat faeces. Dogs that sneak into other people's gardens and bark at the startled occupants. Dogs that make muddy beds for themselves on the pristine white-linen bedding of our gardening clients, or take a poo on their sitting room rug, in front of the TV - while they are all watching it. And every single one of them lets off shell-shock inducing high-pressure, sinus-melting, toxic farts that require full psychotherapeutic counselling to get over, in the middle of the night, while blissfully snoozing mere inches away from your face.

But what we've found is, that, if we wait long enough - without actually showing how seriously, desperately pissed off we are with a complete moron of a newcomer - an almost magical transformation gradually takes place. And that, in time, and with a world of patience, even the most ill-treated or bloody-minded, empty-headed shite-of-a-useless-lump of a dog becomes biddable, willing and eager to please, and as loving as we could wish for. The axiom about it not being possible to teach old dogs new tricks is just so much clichéd and ill-considered crap, in my experience.

My experience is that love mends everything that can be mended. And that gives us all hope, doesn't it? Hope that, by showing ourselves patience and love, and with some incremental change, we can become deserving of all the good stuff life has to offer, not just the shit we often learn to believe is our due.

And then, after all that patience and love, and in a tragically short space of time, our dogs die. Having matured into actually being man's best friend they bloody well die, of old age, or cancer - or, perhaps, defying all the odds, they manage to get out of the front door alone, and wander myopically into a busy road. But more likely still is the scenario that we have to call it, and make the decision to end the life of a creature we love.

Frequently, they leave a little something to remember them by, perhaps to be accidentally stumbled upon a week or so later, as if a gift from beyond the grave. Max, the most gentlemanly German Shepherd imaginable, used to have his bed in the doorless cupboard under the stairs - where, shortly before his final drive to the vet, he hid an epic turd, which quietly dessicated in his cushions, waiting, with a modest smile, to be discovered when I eventually steeled myself into having a clearout of his stuff. Our Rottweiler, Taz left a silly-string cobweb of foamy, sticky saliva in the back of the Audi. On my jacket.

Some of them simply leave us with an unexpected and massive bill, to be finally paid off long after they have peed on their first carpet in heaven. But they all, every one of them, leave us with an ache, and a smile, in our hearts. We wear their name-tags on our keyrings and keep their photographs on our bookshelves, and we miss them terribly.

In the last eleven years I have held nine dogs as one of our wonderful vets has administered the Big Blue Jab, and it sucks - I dread it. But what I hate more is the knowledge that thousands of dogs are destroyed daily for reasons of economy, or over breeding, or simply for the sake of misunderstanding what a dog really is when the idea to have one as a pet first comes up – and that I can't take them all in to live with us.

There are many tough things to take into account when considering bringing a strange dog home. But the toughest thing of all, for me, is leaving the vets with a dog-less lead and collar, for the blurry-eyed and agonisingly slow walk back to an empty car. To go home and put away another stainless-steel bowl that will remain empty for the foreseeable future, having said goodbye to the best friend any one could ever have.

And that, my friends, all adds up to a privileged way of life that I am incredibly fortunate to have. I couldn't do it without my partner, the remarkable Louise, or the support of Burghfield and Goring Vets at www.fullyvetted.com. I am so far beyond grateful for their support that I am a speck on the horizon.

When I began writing this piece we had said goodbye to our dear, old, former ear-shredding, growl-at-you-as-soon-as-look-at-you, head-shy and windscreen-cracking Rotty, Taz, just the day before, and we have a mere four dogs left living with us at the moment - two lurchers and two collie crosses. Each one has brought countless wallet-emptying forehead-smacking moments with him or her, and all have revealed more to me about who I really am, and can be, than would have otherwise been the case.

I'm a lucky, lucky man. Thank you for reading x