The rest of the cast doesn't fare much better. However, part of the problem is the script they've been given to work with. At times, Monster Dog feels like two different films and you're not sure which one your getting at any given moment. Furthermore, the special effects are pretty poor but not so poor that they fall into the "so bad they're good" category. Even for 80's standards they fall short of the mark.
I just couldn't get into this movie at all. I suggest you rent Suck and laugh your butt off instead. It's a very clever spin on the vampire mythology and Alice Cooper is fantastic.
For more info check out the film's entry in IMDB.