Authorities say sun refracted off the dog's shiny water bowl and ignited a fire at Terry and Shay Weisbrich's Santa Rosa home on Wednesday afternoon.
The fire was quickly put out, but it left a hole in the siding.
The Press Democrat of Santa Rosa reports that a fire department engineer helped discover the dog bowl's role in the fire.
Rene Torres returned the bowl to its original position during his investigation of the fire's cause. He found it concentrated light right on the area of the home that was charred.
The Press Democrat says the couple's dog, Toby, had a replacement bowl by the evening.
Copyright 2013 The Associated Press.