Watch: Supervet Noel Fitzpatrick breaks down in tears over late pet
The border terrier died in September and the vet said at the time that his heart was “truly broken” and that Keira had been his “best friend in the whole wide world”.
Opening up about his loss to host Lorraine Kelly, Fitzpatrick said that Keira’s grave is outside his window and that he talks to her every day.
“I cried for, well - the truth is I couldn’t cope,” he said.
“The truth is I woke up every day crying, and I’m treating other people’s animals and I’m crying.”
The TV star ran the marathon this year and said it was the race that helped him to let his pooch go.
He said: "I ran the marathon on a sprained ankle and I was in horrendous pain and a really interesting thing happened.
"I ran it for her, with a photo of her in my pocket, and a very interesting thing happened. When the physical pain met the emotional pain... all of a sudden I was able to let her go, you know?"
"I just let her go around mile 19 on the South Bank… it was beautiful," he added.
Kelly looked emotional as the star shared his story, and viewers were also moved.
“I’m in tears,” one person wrote on Twitter, while another said: “Actually crying watching Noel Fitzpatrick on #Lorraine.”
“Watching Supervet on #Lorraine talking about his wee dog he lost and the unconditional love they give just set me off,” tweeted another.
Fitzpatrick shared in September that Keira had passed away.
Posting a picture of her on Instagram, he said: “I know that she touched many lives with her light. With great love comes great pain, but her love will be inside me forever.
“She inspired everything I do for animals and her legacy will be eternal.”