Jim Leonard is the proud owner of 'inseperable' father and son duo Scruff and Lucky.
Mr Leonard, of Glasgow, has watched on as doting father Scruff acts as a dedicated guide for his two-year-old pup Lucky, who was born without retinas.
He said: "Lucky was blind from birth and it seemed that he was always running or knocking into something and hurting himself. We were really worried about how he was going to cope.
"But we started to take Lucky and Scruff on walks together and it was amazing to see Scruff starting to take charge, looking after Lucky and checking he was okay.
"Now Scruff licks him on the face and guides him where to go. If they are separated for a little while, Scruff will rush over to Lucky and lick him as if to say 'sorry I had to leave you'."
After discussing this condition with PDSA vets, Jim and his family went to great lengths to care for Lucky in his infancy.
Jim even took the unusual step of wearing bells at the bottom of his trousers to let Lucky know where he was.
"When he hears the noise he will follow you," Jim said.
"We also put strong smelling scents like lemon or lime in parts of the room where there are dangers and Lucky knows not to go there. It's hard work to care for a pet with a disability but so rewarding.
"We're extremely grateful to the PDSA vets and nurses at the pet hospital in Tollcross for the help."
PDSA senior vet Elaine Pendlebury said the bond between Lucky and his dad was a touching reminder of canine character and loyalty.
She said: "Dogs can behave in a unique and extraordinary way. They are social animals and can help both pets and people in ways that never fail to amaze.
"It's inspiring to us all that Scruff acts as a guide dog and looks after his son.
"It's nice to see that all of Lucky's family are working together to make sure that he can live life to the full."