Frank Beholm may have had the distressing experience of watching his wife, Maureen, suffer from dementia, but he has no doubt what helped the most. It wasn't medication that improved Maureen's physical, social and cognitive functioning – it was Oscar, a golden retriever specially trained to help couples where one person has dementia.

He said: "Maureen was in the care home for the last year of her life, but she would have been in earlier if not for the dog." After her diagnosis in 2009, Maureen's speech got progressively worse, until she hardly spoke a word, but within a week of having Oscar, Frank heard her speaking to the dog. From then on, he says, the dog was like a buffer, easing communication between them.

Oscrar was part of a small scale pilot – a world first – in 2012 that saw three dogs placed with couples in Arbroath by the Dementia Dogs project, a collaboration between Alzheimer Scotland and Dogs for Good.

The dogs go to live with people in the early stages of dementia, who are still living at home with their carer (usually their spouse) and leading an active life. As Fiona Corner, from Dementia Dog explained, each one is specifically trained for the couple's needs. "We match a dog with a couple and have a trial period when our dog trainer will be there daily. We ask about people's routine. Perhaps they go for lunch at a restaurant? We will go with them and the dog and gradually during those first few weeks we back off so they are leading the dog and we are walking behind them."

The visits become three-monthly, then annually and continue for the lifetime of the dog. If, as was the case with the Benholms, the person with dementia dies, the dog stays in the family home. It is certainly the case that from the very beginning, it is the carer who has responsibility for the dog.

Dementia dogs are generally golden retrievers or labradors since they have got the right temperament, and are a well-known breed that people feel comfortable with, important since not all the charity's clients have necessarily owned a dog before.

Their primary role is to maintain a routine. As well as fetching the medication pouch, the dog can be trained to respond to a different sound alarm, so if he hears that sound he goes to the person, nudges them, and keeps on nudging them until the person follows them to the sound. Glenys, whose husband, Ken, suffers from dementia, leaves a note in the kitchen, saying Ken's dinner is in the fridge, and he needs to put on the oven at a certain time and it is their dog, Kasp, who makes sure Ken sees the note.

An alarm can be left in the bathroom, so the dog takes the person there to remind them to go to the loo. The dogs can learn how to regulate sleeping patterns by waking someone up in the morning and gently nudging them awake if they nap during the day.

As for promoting independence, the dog can bring its lead to show the owner it is time for a walk, and if that is not enough, they can bring a jacket and shoes too. When they come home, the dog can help to remove a person's coat. Anyone who regularly walks a dog will know how they are a natural social icebreaker and open up conversations with others in the community. This boosts the confidence of dementia sufferers and in turn reduces social isolation and encourages independence.

The carers benefit too. The dogs build up their resilience, enabling them to cope better day to day, and can naturally diffuse any tension. When the dog takes care of the routine tasks, the carer no longer has to nag and see their spouse becoming resentful towards them for the nagging. Glenys says that their dog, Kaspa, has "given us our life back". She continued: "Life is so much better for both us of now. Ken is happy and it has taken so much stress away from me as well. Glenys has noticed that Kaspa can sense when Ken is becoming agitated, and will take a toy to him. "That puts a smile on Ken's face," she said.

Those unable to have a dog full-time in their home need not miss out on all these proven advantages. Professionals working in the field of dementia visit people with their specially trained pet dog on a weekly basis, and Alzheimer Scotland's dementia resource centre, in Kilmarnock, is currently trialling monthly dog days, where people of all stages of dementia get together with their carers to enjoy gentle interaction with trained pet dogs and handlers. Families have found that these sessions can trigger reminiscing and opportunities to share meaningful time together.

It is definitely a case of 'watch this space' as man's best friend continues to provide so much more than mere friendship.

To find out more, or to make a donation, please go to www.dementiadog.org, where you will also see fabulous illustrations from the Glasgow School of Art project where students were asked to inject fresh perspectives into service design for people living with dementia.