British Waterways chiefs have vowed to improve safety at Brentford Lock amid concerns raised by a distraught dogowner after his pet was sucked into a sluice gate and swept into the river.
Gareth Evans' 11-month-old white Samoyed Freddie is still missing after falling into the Grand Union Canal on Sunday, January 25.
Gareth, of Westbury Place, is clinging onto the faintest of hopes that his beloved pet is still alive.
But he has issued a dire warning over the flimsy chain railings that are currently in place.
He told the Chronicle: "What if it was a child feeding ducks? If they fell in, then that's it, it's game over."
Gareth, 33, an IT worker, said he was walking Freddie and his other dog on a regular route around the GlaxoSmithKline building and back when they reached the lock at around noon.
"When we reached the lock there was debris which had collected near the bank," he said. "Freddie thought it was solid ground and just went through. He went down like he was being sucked down a plug hole."
Gareth started fishing around with his hands and feet without luck, while another man who had jumped into the water from his canal boat gave up because of the underwater current.
The gate was eventually closed but Freddie was nowhere to be found and it is believed was probably swept into the Brent.
"I'm desperate to find him," Gareth said. "There's a one per cent chance he could've survived it. But even if we just find his body, I want to know what happened to him."
He also said the incident has left him with a number of questions.
"One thing I want to know is why there are no railings there," he added. "In the sales brochures when they opened the nearby flats you can clearly see fence panels. What happened to them?"
But local Lib Dem ward councillor Andrew Dakers said he was not sure railings would make much difference.
"I can see the risk highlighted,but this would also be the case 15 yards away," he said.
Cllr Dakers instead advocated increased education about the dangers of the lock and also said every child should be given the opportunity to learn to swim.
But Simon Bamford, general manager of British Waterways London, admitted: "This has been a very upsetting incident for everyone involved, and British Waterways is working to ensure that further safety measures are put in place in Brentford to help prevent any further accidents."
He said the organisation plans to introduce a number of safety measures at the marina in coming weeks, including a new pontoon for boaters, a lock ladder, further fencing around the waters edge near the sluice gate area and warning signs.
"In addition we are going to divert normal water flows through Stoney Sluices, which are to the east of the island," he added. "This will reduce the flow of the River Brent into the marina."
Mr Bamford said temporary fencing had been put up around the area ahead of the works because of the accident.
Anyone with information about Freddie should call Gareth on 07717 817 529 or Jenny Laurens on 07725 032 654.