Nylabone makes a couple of strong chew toys that have worked well for my dogs. I don’t like to leave any dog with a Kong toy or ball since a hard chewer can bite off pieces and swallow them.

Their Galileo Bone in the largest size is almost indestructible, the one I have is barely chewed, it is just sort of scratched on the ends. These are heavy and solid and they hurt like hell when the darn dog drops it on your foot!

http://www.nylabone.com/product-find...lileo-bone.htm

They also make a line of “Big Dog Chews” and I have the Beef Bone one –

http://www.nylabone.com/product-find...-beef-bone.htm

My dog likes this one better, I guess the shape is easier to chew on, she does not like the Galileo bone as much.

I have also had some of the regular Nylabone chew toys in the Original Souper size, those don’t last as long and get whittled down to a vampire stake looking thing after awhile. The Nylabone company told me that the toughest plastic is the Original and don’t buy any of the flavored ones for a strong chewer. They said the Galileo and Big Chews are the best for hard chewers.

But of course, use caution with anything you give your dog. One of the best things I used to give my old dog was a big raw cow femur with some meat and gristle attached. That would be her meal of the day and she’d chew it for hours.