I've seen scarier episodes of Scooby-Doo.

Stephen King lists this movie as one of his 10 favourite adaptations of his works. Over Carrie, The Shining, and The Dead Zone. I don't know what he sees in this one.
Problems with this film are numerous: the action doesn't get started until 40 minutes in, and then quickly gets stuck in a single location; the direction is workmanlike and bland; the dog is never convincingly threatening, with lots of fast cuts and shaky camera-work to convey a lot of the attacks; characters often make stupid decisions so that the plot can put them and others in danger; almost all the characters are annoying and unlikeable, particularly the little boy; the sub plots of the affair and the ad campaign aren't all that interesting and take up far too much time.
There are some good points, though: Dee Wallace is good and convincingly portrays the exhaustion and terror of someone in her situation; she's also pretty good in the sub-plot of the affair, putting in a reserved but believable performance and helping to evince sympathy for her character; Jan de Bont photographs the film well; and there were two or three genuinely tense moments.

It's Beethoven! It's just a dog covered in mud and white and yellow foam, his eyes just look healthy. Even felt sorry for the dirty St. Bernard.