Howling IV is essentially a remake of the first movie (or a re-adaptation of the books if you prefer) therefore bizarrely including in in the canonical numbering seems a bit odd. As the the obvious redubs of pretty much all of the sound throughout.
The best I can say about Howling IV is that it hasn't got a furry pouch like 3 or furry sex like 2. In addition… nope I have nothing. The acting in places is awful. The characterisation abysmal and the effects laughable. There is nothing to redeem this one.
Terrible film, avoid like a pox ridden tuppenny whore.