Yes. Dogs are perfectly willing to eat human corpses, and there's no evidence that they treat their masters differently than any other dead body. Many cultures consider dogs unclean precisely because of their tendency to scavenge our remains. In The Iliad, Homer makes nine references to dogs eating dead bodies. Dogs consumed the body of Jezebel, a princess in the Old Testament, after her defenestration.
There is evidence that ancient Romans considered the low-hanging cross a crueler form of crucifixion than the high version, because it enabled dogs to rip the body apart. There are even a few secular historians who believe that Jesus' body was eaten by dogs, and that his acolytes fabricated the story of a reverential entombment as a sort of coping mechanism. Some Muslim communities in East Africa revile dogs because they believe that canines ate the body of the Prophet Muhammad. Modern dogs exhibit the same behavior, and many have eaten their fallen masters. There have been several news stories of dogs scavenging family members, and other cases go unreported in the press. (Don't get smug, cat lovers. Your feline friends are no better.)
Dogs that eat their master's corpses are just fulfilling their evolutionary duty. Proto-dogs scavenged around the outskirts of human settlements about 10,000 to 12,000 years ago, removing food scraps, feces, and other human waste. Humans, the story goes, realized this was rather useful, and let the least aggressive pups hang around. It's likely that these canine garbage-compactors treated corpses like any other waste product. Their descendants are no different.
Some dogs don't even wait until their masters die to dig in. There are many reports of dogs eating the wounded toes of family members. The victims are often afflicted with diabetes, which causes numbness in the feet, and they can't feel the dog gnawing at them. Epidemiology studies also undermine the desire to believe that Fido would never turn on us. More than 900 people visit U.S. emergency rooms for dog bites every day, and more than half of those attacks occur at home.
Finally, it's noteworthy that there were seven man-eating dogs in the Saskatchewan home, rather than a single pet. Behaviorists point out that dogs are more aggressive in packs (PDF), with more timid individuals joining in after their peers launch attacks on humans.