For the last seven years, Kevin Seabrook and his guide dog Jake have been inseparable.
Next Friday, however, they will go their separate ways, Kevin to a new dog and Jake into a well-earned retirement.
The Labrador-retriever cross is almost 10 years old, the age at which guide dogs must retire.
But, while Kevin knows coping with his retirement was always going to be a necessary part of having Jake, it does not make the process any easier.
“Giving him up is a huge thing – it is going to be devastating,” he said.
“I was a lot less confident before I had Jake and he has made my life so much better.
“He has slowed up a lot recently and is ready for retirement – but he has been a brilliant dog.”
Fortunately, rather than saying goodbye forever, Kevin has arranged for Jake to live out his retirement with his dad in the seaside town of Mablethorpe.
“If my dad would not have taken him I would probably have never seen him again,” he says.
“He is going to have a lovely time there on the beach but I think he will miss working.”
Kevin has an inherited degenerative condition called retinitis pigmentosa, which has now become so bad that he only has 20 per cent of his vision left.
He likens it to curtains slowly closing in to a central point which gets ever smaller and may one day rob him of his sight completely.
The 40-year-old used to work as a chef at the cafe in Graves Park but, after being declared legally blind in 2010, has been unemployed since.
“It is not through lack of trying,” he says.
“In nine out of every ten cases employers’ insurance won’t cover me to work there.
“And when the government shut Remploy down four or five years ago that was it for me really.”
Nevertheless, he says Sheffield is fantastic for those who are disabled, with excellent public transport links and the best RNIB in the country.
When he is not working, Jake becomes just like any other pet.
He barks and bounds up to visitors and loves to play with a ball when out for a walk.
In the harness, however, he switches into work mode and has a completely different personality.
Over the last seven years, the pair have worked together as a team to safely navigate the world.
“The main problem for me was what was going on below waist height,” says Kevin.
“I used to bang into children a lot and the most embarrassing moment was when I went over a chair and ended up on a glass table at the Royal Bank of Scotland.”
It took Kevin a long time to learn to trust Jake, something he must now do all over again with his new dog.
The new dog he has been paired with is a giddy one-and-a-half-year-old Alsatian-retriever cross called Uri.
However, despite his quick match, there is a chance the relationship will not work and Kevin will have to try again with another dog.