It's just after 5pm when seven-year-old Declan bounds through the front door in his school uniform, bubbling with energy

A sturdy russet Labrador pup scrambles to play with his best friend after a long day at school, but Benji is more than just a family pet - he's in training to become Declan's assistance dog.

Declan McInnes-Pirie was diagnosed with autism just a few months before his third birthday.

He suffers from anxiety and has a tendency to run off when confronted with stressful situations, meaning his parents have to constantly hold his hand when they go to the shops or for a walk in the park.

"He has no concept of danger or pain, which was what first led us to have concerns," explains his mother, Phionna.

"Declan contracted swine flu in 2010 and it was during his recovery that we realised he had missed a few milestones.

"His recovery was very slow and his speech had regressed. He was echolalic (where a person will echo words and noises made by another person) for 18 months until I could get his speech by using puppets."

It has made life challenging for the family of four from Aberdeen. Phionna explains that Declan, seven, has trouble understanding the world around him and looks to his elder brother Rogan for support as he finds it difficult to make friends.

Phionna says she has been forced to sleep in the hallway outside her son's bedroom ever since he learned to climb out of his cot five years ago to prevent him trying to open his bedroom window or wake his brother in the next room.

She didn't know where else to turn when she came across A Friend called Henry, a book about a family in Glasgow who had noticed an improvement in their own child after getting a dog.

Convinced an assistance dog that would grow up with Declan was the solution, mother-of-two Phionna searched the web for help.

It became clear to the family they would have a long wait before they were even considered by an Assistance Dogs International (ADI)-approved charity so Phionna decided to fund the training herself.

She turned to an Irish firm to provide a fully-trained service puppy in exchange for £5000 raised from events such as bake sales and race nights over the course of four months.

As Declan crossed off the days on his bedroom calendar until he would meet his new best friend, the family were left devastated when the company suddenly shut down, vanishing with more than £1000 of their money.

Explaining to Declan what had happened to the dog would have been impossible, Phionna says.

Luckily, her father knew of a breeder in Aberdeenshire who reared puppies for families with additional support needs in the past.

With a recent litter of fox red Labradors in his care, the breeder recommended a puppy to the family and, at nine weeks old, Benji was introduced to Declan for the first time.

The bond between the boy and his dog was instantaneous. When Benji arrived at the family home, he bypassed the couples elder son and sat by Declan's side.

Benji has now been given training to become an ADI-accredited dog, which would give the puppy the same rights as guide dogs to enter buildings and public transport.

Phionna says: "Benji is a smart wee thing and has picked up all the commands he has been taught so far. Most importantly there is an incredible bond between Declan and Benji, where there is rarely one without the other."

Now six months old, Benji has responded incredibly well to his training, mastering a technique using a mechanised clicker in two days which allows him to learn new behaviours through noise and positive reinforcement.

Benji's harness training has also helped with Declan's tendency to run in stressful situations. The pair are joined together using a harness and handle, with Benji learning to anchor himself if Declan is spooked, physically stopping him from running away.

Simply holding on to the harness has helped give Declan the independence to walk safely in a park with his family, something which up until recently would have been a stressful experience for the whole family.

Phionna says: "We are able to get out to the park as a family now - something we havent been able to do for years as Declan would bolt off when he got anxious and my stress levels would be though the roof.

"It has encouraged both Dennis and I to take turns taking Benji for his walk in the evening, which has become a bit of a stress reliever for us both too."

Benji has even taken to pressure therapy, which calms Declan when he is in an autism-related meltdown without any real training. By simply placing a paw or leg on the seven-year-old, the pressure helps to reduce Declan's anxiety.

It is hoped once Benji is a fully-trained service dog, in around 18 months time, he will be able to move from his crate to instead sleep outside Declan's bedroom, relieving Phionna of her late night sentry duty and instilling a sense of normality for the family.

Delighted with the progress Benji and Declan have made together, Phionna says: "We have a much calmer boy. We can shape his behaviour a bit better now by telling him Benji doesn't like what he is doing.

"He takes home pictures he has done at school and want to give them to Benji. Benji has also been great for homework as he is very good at listening to Declan's reading."

With the added responsibility of feeding and watering Benji, the puppy is learning to recognise Declan as his master as well as instilling a sense of independence within the young boy.

Phionna says: "The plan is that Declan can learn to think about others' needs as well as his own and perhaps will be able to make friends through Benji. After all, having a dog is quite social and he is very happy to talk to people and tell them all about his dog."

After Benji passes all of his ADI training, he will officially become Declan's autism assistance dog as well as his best friend, supporting each other as they grow up together.

"Benji has been wonderful, he has really had his personality tested with Declan and he has risen to the challenge every time. Never have I seen such loyalty, patience and compassion.

"There has been many a happy tear shed in this house. You read about it, sure, but until you see it happen with your own child - well that's some experience.

"It's worth everything we put ourselves through. Getting Benji was the best thing we could have done."