Nicholas Murphy was left devastated after he claims his pet dog was "mistakenly put down" by local vets.
Gunner the dog was taken into the DJB Denny Veterinary Practice in Worcester after suffering from a persistent cough.
But Mr Murphy was stunned to find out medics had given his 14-year-old Jack Russell a lethal injection instead of the necessary antibiotics for a cough.
When Nicholas questioned vets about the error he said he was told "mistakes do happen" and was asked if he wanted to bury his pet at home.
David Denny from DJB Denny Practice told BBC Newsbeat that "it was a terrible misunderstanding" and said he was very sorry for the mistake.
The 22-year-old said he couldn't believe he had to return home to his family and tell them the news, when all he'd asked for was stronger cough pills.
The family made a grave for their beloved dog Gunner with a message reading "R.I.P Gunner. Miss you loads."