The movie involves dogs of all sorts (no pit bulls, mostly german sphererds) that attack a group of people stranded on what seems to be an island. They are trapped in a cabin/house. The dogs try to dig their way in the cabbin/house. The few who survive use iron type barrels tired together to escape to a near by beach. They then use these barrels to float away from the island. I am 32. I remember seeing this movie when I was 8-10 years old on television for the first time.

The Pack (1977) - IMDb user comments (http://www.imdb.com/title/tt0076516/usercomments) ?

There is a remake following this same description called "The Breed" by Wes Craven. I haven't seen the original though. The names might have changed.