On a sunny mid-August day in 2015, Lee Green left his van – with the window down – for only a few minutes as he popped into a sandwich shop in Busby, East Renfrewshire.

Inside the van, happily waiting for his return, was his Jack Russell puppy Cooper, just four months old and the beloved pet of Mr Green’s two-year-old daughter, Eva.

But on his return Cooper was gone, snatched by a stranger through the van’s open window, leaving Eva devastated and sparking a social media campaign for the canine’s return.

It took two and a half years but, in January, completely out-of-the-blue, there was a happy ending for the family from Carmunnock, in the south of Glasgow, when they were reunited with Cooper.

He was found by a dog warden in Ayrshire, who took him to a police station and identified him by scanning his microchip.

 The family believe he was taken to be used as a stud dog, but he was in good health and happy to be home.

Mr Green said: “The warden and the police were great. And, to top it off, Cooper looked in good health. He and Eva hit it off right away and it was as if he’d never been away. It is amazing because after being away for so long we never thought we’d see Cooper back.”

For many, though, the hunt goes on.

Statistics show dog theft has increased in the UK over the past two years, with an average of five dogs reported stolen every day in 2017.

The figures – compiled from Freedom of Information requests to police - show 1,909 dogs were reported stolen last year, up 6.8 per cent from 1,788 snatches in 2016 and a 14% increase on the previous year.

Campaigners and animal charities say the pets are being stolen for resale, breeding or fighting.

But the rise in thefts is also being blamed on the trend for owning “designer dogs”, with some breeds seen as being popularised by celebrities such as Madonna and Cheryl Cole. 

Insurance firms say the right breed can fetch hundreds, and sometimes thousands, of pounds on the black market, with Staffordshire bull terriers, French bulldogs, Chihuahuas and Jack Russells the most commonly targeted in 2017.

As well as dogs, certain pedigree cats are also at risk but in much smaller numbers.

Head of pet insurance at Direct Line, Prit Powar, said: “The fashion for certain types of dogs means people are willing to pay thousands for an animal, which unfortunately makes them prime targets for thieves.”

Nicola Cree, of Kilmarnock, contacted the Dog Theft Action charity when her eight-year-old male Elkhound, Bragi, vanished near home in June 2014. 

She said: “The day he was stolen, my whole world fell apart. There is not a day goes by that the kids do not talk about him and I do not cry for him. I would give everything to cuddle him and see his face again.”

This week alone on Missing Pets Dundee and Angus, one of the many Facebook sites for lost pets, appeals have been put out for animals feared stolen.

Glen the collie dog, who requires heart medication, was “still missing, presumed stolen” yesterday, from Charleston in Dundee. And on Sunday, a warning went out after an apparent attempt to steal a cat.

A post read: “Some woman grabbed my mum’s outdoor cat early hours of morning when he was going on his usual walk. She tried to take him away with her, she wasn’t trying to return him as he’s got the address written on his collar and she was walking in the opposite direction. My dad luckily drove past her and saw it, she then dropped the cat and ran off”.

More than 106,000 people have signed a petition calling for pet theft to be made a crime in its own right, saying current sentences do not act as a deterrent.

The petition led to a debate in Parliament, during which some MPs called for tougher sentences for those found guilty and there was “outrage” expressed at the low conviction rate.

However, minister for agriculture, fisheries and food, George Eustice, said the Government was “not convinced” a law change was required, believing the 1968 Theft Act offers “sufficient sanctions”.

Conservative MP for Aberdeen South, Ross Thomson, said there was a need to make pet theft a serious criminal offence in its own right to reflect the “deep emotional harm” to victims. He proposed a change in the law to Westminster this week.

Under current laws, stolen pets are treated as possessions, but Mr Thomson said an offence should be created to reflect the animals being “part of the family”.

He said: “Pets are very much part of the family, they are not possessions like a car or HD TV. For anyone unfortunate enough to have experienced pet theft, it can be truly heart-breaking, distressing and devastating. The theft of a pet should be recognised as a serious, criminal and punishable offence that recognises the status the animal has within their family. I want to see tougher sentencing guidelines to deal with those that are caught”.