Corey Haim is never going to be known as one of the great actors of his time, but at least in movies like "Licensed To Drive", he was more in his element... lowbrow humor.
Dean Koontz's book "Watchers" was one of his earlier works, and still probably his finest to date. Sadly, this magnificent tale of a brilliant dog, a deranged mutant and a genetic experiment gone wrong is butchered horribly. The acting is so lifeless, you might think you're watching a zombie movie. Only the dog gives a respectable performance, and if you want to see a decent movie about a dog, you'd be better of watching "The Incredible Journey", "Cujo" or even "C.H.O.M.P.S."...okay, maybe not "C.H.O.M.P.S."
If you've read the book, avoid this movie at all costs. If you haven't read the book, read it and avoid this movie. You'll thank me later.
A somewhat better translation of a Dean Koontz book is the capable thriller, "Phantoms".