For those of us who love dogs in the same way other people love people (only we love dogs a bit more), the object of life is simple: a dog of one’s own. It is also elusive: modern life may as well have a “beware of the dog” sign slung round its neck, so unwelcoming is it to the humble hound. As my dad put it, slightly offensively considering that I am his two-legged daughter: “Dogs are more of a responsibility than children. You’re not ready.” He was right, I wasn’t.

It was 2012. I was 33 and working full time as a journalist in Edinburgh. I lived in a flat, went out a lot, ate out a lot, worked on planes and trains a lot, and exercised not so much. Life was good, busy, easy, pleasure-driven. I had a great deal of freedom – the most I have ever had, in retrospect – but it was also a time characterised by yearning (which I now think often accompanies an unrecognised surplus of freedom). I wanted, in no particular order apart from the first one: a dog; to go hillwalking more; travel less; have a baby; write a book; sort out my chronic back pain from years of typing thousands of words a week; learn the names of trees, flowers and birds; and so on. None of it seemed possible, especially the baby. My partner, Claire, and I had been trying for more than a year and were on our second donor. The quiet cyclical disappointment of not being pregnant was beginning to seep into other parts of my life. We went on holiday to Orkney and, on a vertiginous walk around a headland whipped by northern wind and vertical sea spray, I watched a couple with their baby in a carrier and a dog trotting at their side and felt lost.

Two weeks later, a “petite one-year-old staffordshire bull terrier cross currently in a foster home in north Devon” showed up. We found her online – or, as all those who adopt like to think, she found us. She had been saved from a council pound just hours before she was due to be put to sleep. We looked at a photo of her, eyes closed, ears up, sunning her bald staffie belly on a Devon step, more than I have looked at any other photo. Our lives were in no way ready, but we took a leap of faith and adopted her.

Everyone told us we were mad, which was annoying, but I also feared they were right. Daphne (after Daphne du Maurier, as opposed to Daphne Broon from The Broons as is generally assumed in Leith), was traumatised. She barked at the shelves. She cried for hours after the volunteer, on whose lap she had insisted on sitting for the duration of the 450-mile drive from Devon to Edinburgh, left. We tried to put her in doggy day care but she ran around like a maniac all day and got a frozen tail, which is an actual ailment requiring treatment. She stood on broken glass and I had to pull the shard out of her paw and carry her home, both of us spattered in blood and shaking. She would not sleep anywhere but on top of us. The responsibility was literally and figuratively engulfing. And yet she was here. She was my dog and, as all dog lovers know, so much of our daily unspoken happiness is rooted in the simple act of watching a dog be a dog. She grunted, smiled and sang like only a staffie (and a seal) can. She possessed the most marvellous black and white toenails. She wanted only to be with us.

What was amazing was how this dog changed everything. It was like an epic and gradual cascade; an avalanche in slow motion. Two weeks after Daphne arrived, I was pregnant. By the time the baby was born, I was plotting my first book; eight weeks after the birth, I was writing it. And the changes, major and minor, kept coming. We stopped travelling and I haven’t been abroad, or even on a plane, for seven years. I took voluntary redundancy from my job and went freelance; something I had been threatening to do for years. I spent my maternity leave walking (dog and baby) and writing (about walking, baby and, sometimes, dog). I learned the names of some trees. Life got harder, scarier, better.

Seven years later, life – and change – goes on. I have another baby. I work from home. We have moved flat. I have found a really good physio for my back. The dog has a grey muzzle and bumpy haunches from the removal of some tumours. I write these words as she snores beside me, sighing deeply when I tweak her ears for inspiration, as is our way. It would be foolish to suggest that a dog is responsible for the life I lead now. Yet, like a dog carrying a stick to its owner, what she brought into my life was the reward of responsibility. And that changed everything.