A blind therapy dog called Smiley held his owner’s hand hours before he died.

The golden retriever spent 12 years comforting patients in hospitals, schools and care homes in Ontario, Canada.

But vets found tumours on the 15-year-old dog’s liver and stomach in July, leaving him with months to live.

His devastated owner Joanne George documented the last months of Smiley’s life to his 300,000 social media followers.

How do I thank him for what he’s done? How do I say goodbye? It’s almost time to give him back. How do I just go on without him? A post shared by Joanne George (@smileytheblindtherapydog) on Oct 14, 2017 at 8:07am PDT

Smiley died on Saturday, holding Ms George’s hands hours before vets put him to sleep.

“The little dog with such a huge purpose has been let go”, Ms George wrote on Instagram.

“He left us so quietly and peacefully in his favourite spot today at 12:30.”

“Please, in honour of Smiley - see the world around you with your ❤️, be kind to others, and give back in any way you can.”

There is no shame in wanting to be larger than life. @popyourpup nailed Smiley's image on this huge canvas. Thank you so much!! His smile will always brighten our home now. A post shared by Joanne George (@smileytheblindtherapydog) on Sep 25, 2017 at 4:29pm PDT

Smiley was born blind due to a dwarfism-related condition, and his eyes were later sewn shut to stop them getting infected.

The condition also gave him oversized teeth, meaning he always looked like he was smiling.

So much to be thankful for. Smiley brings so many people hope and joy. ❤️He inspires. ❤️He makes us all smile. ❤️I am thankful for everyone who prays for him. A post shared by Joanne George (@smileytheblindtherapydog) on Oct 7, 2017 at 9:29am PDT

Smiley spent his first two years in a puppy mill, a commercial farm in which dogs are bred for sale, often in inhumane conditions. After his owner Ms George rescued him from the puppy mill, Smiley trained as a certified child therapy dog with St John Ambulance.

He visited children, often with the same disability as him, in hospitals, school and care homes. He also comforted children who had experienced a death in the family.

Thank you Evan for coming to meet me today. I was happy to pawprint your book for you! Last time I met you, you were in your mama's tummy! A post shared by Joanne George (@smileytheblindtherapydog) on Sep 22, 2017 at 9:03am PDT

"People say they feel like a different person after meeting Smiley," Ms George told the Huffington Post in 2015.

“These kids who were born with different disabilities are able to see that dogs, too, are born with the same disabilities.