A vet that put down 200 dogs with an outdated practice that caused them to scream in agony before they died has been struck off.

John Hendrie Smith, 89, injected dogs into their hearts in a process believed to cause 'appalling pain'.

Hendrie Smith, who has been a vet for nearly 65 years, was found to have used the controversial technique on hundreds of helpless animals at the Valley Veterinary Centre he ran in Galston, Ayrshire.

Pet owner Darren Stevenson with his dog Bounce. John Hendrie Smith, 89, injected dogs into their hearts in a process deemed to cause 'appalling pain'

Pet owner Darren Stevenson had called on Hendrie Smith for help with his terminally ill German Shepherd Bounce, according to records of a disciplinary inquiry.

But the vet had failed to bring a muzzle and instead tried to wrap his belt around the dog's snout in order to bind its mouth closed.

He also asked to borrow pliers from Mr Stevenson to fix a syringe before the needle was inserted through a lung wall. Due to a dense nerve network, it would have caused the animal excruciating pain.

Rachael McRoberts, 34, Mr Stevenson's partner at the time, heard the dog scream in distress as it was put down.

She told Jonathan Leake and Shingi Mararike of the Sunday Times: 'It was horrible. the dog was wailing for what seemed like ages. I've never heard a dog make a noise like that.'

Ms McRoberts remembers Bounce as a protective animal who was a companion to her family, including her three children now aged 16, 12 and five.

Mr Stevenson's partner at the time heard the dog scream in distress as it was put down

She said: 'He was kind of human...he understood you and knew if something was wrong with the kids and would alert me.'

Mr Stevenson complained to the Royal College of Veterinary Surgeons (RCVS), who found that Hendrie Smith had been using the painful technique a number for years.

He admitted that many animals wailed in agony before dying.

RCVS investigated Hendrie Smith and the case raises questions on veterinary regulations and why an ageing practitioner had not been subject to routine checks.

The RVCS advises vets: 'It's up to you to decide how best to fulfil your learning needs.'

Hendrie Smith could not be reached for comment.