Toronto emergency crews received a call around 2 a.m., after the dog was electrocuted in the Keele St. and Dundas St. W. area., said Toronto police Staff Sgt. Mary Shaw.
The dog stepped on a metal plate at the base of a pole and "instantly lost consciousness and fell to the ground in convulsions," Shaw said.
Firefighters tried to resuscitate the five-year-old labrador-poodle mix using CPR for about 20 minutes, but were unable to revive it.
Toronto Hydro grounded a live wire at the top of the pole, said Shaw. Toronto police have advised Hydro to investigate all of the poles in the area.
A German shepherd died in November after being electrocuted near a light pole in the same neighbourhood.