I know he’s trouble before he even sets foot in the building. I can tell by the way he slams the door of his 4×4 and storms across the car park without waiting to see if his short, bespectacled wife is following him. When he reaches the glass double doors to reception, I avert my gaze back to my computer screen. It’s best to avoid direct eye contact with an aggressor. When you spend twelve hours a day with dangerous animals, you learn a lot about confrontation, fear and hostility – and not just in relation to dogs.

The bell above the doors rings as the man enters the reception area, but I continue to enter the details of a seven-day evaluation into the computer database. An Alsatian-cross called Tyson was brought in by an inspector a week ago. We’ve been evaluating him ever since, and I’ve identified behavioural issues with other dogs, cats and humans – unsurprising in a former drug-den guard dog. Some people believe that a dog like Tyson should be put down for his own good, but I know we can rehabilitate him. Your past doesn’t have to define your future.

“Where’s my fucking dog?” The man rests his elbows on the reception counter and juts out his chin, contempt etched onto his thin, sunken face. His shoulders are narrow beneath an oversized leather jacket and his jeans hang loosely from his hips. He can’t be much older than late forties, early fifties tops, but he looks worn down by life. I suspect he’s the sort to own a dangerous breed. Small man, big car. Big dog, too. No wonder he wants him back. He’s missing his canine penis extension.

“Can I help you?” I swivel round to face him, and smile.

“I want my dog. One of my neighbours saw the inspector turn up when we was out. They took him out the back garden. I want him back.”

“He’s called Jack, he’s a Staffordshire bull terrier and he’s five years old.” His bespectacled wife puffs into the reception area, her black leggings sagging at the knees, her pink lipstick neatly applied and her grey-streaked hair scraped back into a tight ponytail.

“And your name is?” I look back at her husband.

“Gary. Gary Fullerton,” the man replies, ignoring his wife.

I know the dog they are talking about. Jack was brought in four days ago. His right eye was so swollen it was sealed shut, his lip was torn and bloody and his left ear was so mangled the vet had to remove half of it. He’d been in a fight but it clearly wasn’t a one-off. You could tell that by the scars on his body and the wounds on his face. This owner’s obviously fresh from the police station. On bail pending a hearing, probably.

My smile fades. “I’m afraid I can’t help you.”