The Capital couple are also offering a £1000 reward to find their Parsons Russell terrier Jeff who disappeared during a walk in Newbattle Woods near Dalkeith.
Janeanne Gilchrist, 43 and partner Will Beeslar, 38, have set up a Facebook page called Find Jeff Reward £1000 Scotland.
The rescue dog was said to have been spotted close to the Old Dalkeith Colliery gypsy traveller site but has not been seen since.
Ms Gilchrist said she was “gutted” when Jeff disappeared while she was out walking her other Parsons Russell terrier Molly, and her mother’s Yorkshire terrier Charlie.
She said: “Since then I have combed those woods and fields day and night. We are just broken by it.
“Jeff is more than just a dog – he lives his life to the max with us and was included in everything that we have done over the last eight years. He is our best friend.”
Ms Gilchrist has now approached the Pet Detectives Limited and will engage its services after “all leads have been exhausted”.
The Pet Detectives, based near London, is the only detective agency in the UK that specialises in tracking down missing and stolen animals.
Colin Butcher, company director, said that he had spoken to Ms Gilchrist, who was keen to engage his services, and had given her some free advice.
Mr Butcher said: “A police officer who had been on this traveller site is 99 per cent certain that the dog she saw was this lady’s dog.
“I have given her a list of things to do rather than charge a huge amount of money because this is what we do in the early stages with clients.”
He added that cases of dogs being stolen and exchanged was becoming an “increasing problem” nationwide.
Ms Gilchrist initially assumed that Jeff was out wandering in the woods and would come back or that someone had picked him up and would return him.
But because the woods are used regularly by dog-walkers, she is not ruling out the possibility that Jeff was stolen.
She said: “I was not aware how many pets have been stolen over the past few months, and the stress, upset and devastation it leaves owners in.”
Police were unable to confirm that a dog matching Jeff’s description had been spotted by an officer. But they said they had received a report of a dog having run off when out for a walk with his owner and that they were investigating.
Signs for attaching to lampposts have been donated to help publicise the appeal.