Nash is a seven-month-old black lab/Burmese mountain dog cross. Labacher is a volunteer trainer with the MIRA Foundation, which trains and provides guide and service dogs in Quebec.
Labacher says when he and Nash boarded the city bus Friday morning, the driver pointed to the seat reserved for people with disabilites and said they should sit there.
"There was somebody already sitting there and I said, 'No no that's OK, I'm happy to sit further along,'" Labacher says.
He said Nash generally finds the disabled seat a bit crowded, so Labacher prefers to sit elsewhere with him.
But the driver was insistent.
"Then he put on the air brakes and said, 'We're not going anywhere, and you can either sit there or get off.'"
Labacher and Nash reluctantly got off the bus and took the next one without incident.
Driver got it wrong
STM spokesperson Amélie Régis told CBC News that people with service dogs are welcome on all STM vehicles and that are not required to sit in any designated seat. She said some drivers recommend the seat reserved for people with disabilities, but people with dogs are not obliged to sit there.
Régis says if Labacher chooses to file a formal complaint, the STM will investigate.
Labacher says this has happened to him and Nash three or four times before on STM buses, and each time he's had to explain to the driver the STM policy.
He says it's clear more training is required.
"One of the tasks for a bus driver is to welcome guests on the bus, and to know if they have a service dog or a service dog in training they should be treated like anybody else," Labacher says.