The best for exercising big dogs
These aren't cheap, but worth every penny. They're good, tough rubber, but not solid so they don't break your dog's teeth when they catch them on the bounce. They're brightly colored so you can find them in the brush, and they don't deteriorate in the rain if you can't find them for a while.

Chuckit Unltra Ball
We have a German Short Haired Pointer, who likes to chew his toys. He has very strong teeth, and can destroy anything quickly. This is the first toy we have found that he cannot make a real dent in. We are confident in this product and will buy more or similar products.

throw old tennis balls away
My lab loves to fetch, and after a day of retrieving, a normal tennis ball begins to deteriorate after being chomped, chewed, and played with. These rubber balls last a long time and they can be thrown much further. We don't use anything else anymore.

Best ball for dogs
My dog would routinely destroy tennis type balls in just a couple hours.
This has been around for weeks now and is still in good shape. It's light enough for him to catch without damaging his mouth yet tough enough to stand up to his chewing. He much prefers it to his Kong ball which is too hard for him to catch safely.

Dog loves it...
My pit ball loves to play with these. She did manage to destroy one of the balls, but it withstood her chewing for several weeks. Luckily there were two balls so she still has the other one to play with. I would highly recommend for Medium size dogs and smaller, as a larger dog may try to swallow them.