A pet dog is believed to have died in a fire that destroyed a two-storey log home in west Ottawa, leaving a family of four homeless.

A passerby reported the fire after seeing thick smoke and heavy flames coming from the roof of a home on Upper Dwyer Hill Road at about 12:45 p.m.

By the time firefighters arrived, the home was fully engulfed in flames.

When fire crews got to the scene they focused their efforts on stopping the flames from spreading to two large propane tanks and the surrounding forest.

Nobody was home at the time of the fire. However, firefighters believe a golden retriever died in the blaze.

The fire caused an estimated $400,000 in damage.