An unidentified man was walking his German shepherd Thursday evening in the city's west end when the dog paused at the pole owned by the Toronto Hydro utility, the Toronto Sun reported.
The animal made contact with the pole, recoiled and collapsed. Fire Capt. Adrian Ratushniak told the newspaper resuscitation attempts failed.
"It looks like they were trying to work on the dog for about 15 minutes without any return of vital signs," he said.
A police officer rushed the dog to a veterinarian, who pronounced it dead, the newspaper said.
Toronto Hydro spokeswoman Denise Attallah said an investigation would be done, but a spot check of the pole Thursday night found it to be safe.
The Sun quoted the Boston Globe as reporting four dogs were shocked and one killed in that city in 2005 by faulty wiring on city utility poles.