Balls hold a special appeal for many dogs and can even be an object of obsession compulsive disorder (OCD.) I have owned a “ball crazy” dog therefore I know a lot about balls! BTW, if you do have a dog that is truly obsessed with balls, it is best NOT to let them have them; the risk of the dog ingesting a ball or piece of a ball and the risk to humans or other dogs who try to take the ball away are great. These dogs are usually highly toy oriented and can be happy playing with other toys with less potential to trigger obsessive behavior.
For a dog that loves to play fetch, few toys match the appeal of a tennis ball. I recommend buying human grade tennis balls, as the "tough for dogs" balls, while having a thicker skin, are less flexible and more likely to crack when chewed. You can often find oversized tennis balls in the sporting departments of discount retailers and these will often hold up better for hard chewing dogs. I know smaller balls are available for flyball competition for smaller dogs, I am not familiar with the quality of these as frankly the choking risk is far to high for me to allow them in my house.
That said, this is a toy that cannot be left alone with a hard chewing dog, as they can easily be punctured, cracked, or even peeled by the industrious canine.
The classic in this category is the English brand Cressite solid rubber ball, Kong also makes a good solid ball. Author Marsha Boulton sells “Wally Balls” which held up to her famous Wally the Wonder Dog who she immortalized in a book of the same name. My most ball-obsessed dog, Mitch, was able to play with these without damaging them, but you must remember that sphericality (is that a word?) was the most important feature of any ball so he rarely chewed up anything round. Anna Nicole, on the other hand, has never met a rubber ball she couldn’t destroy, so these hard rubber balls, while safe for most hard chewers, are not safe for all. Anna’s technique is to chip at the ball with her front teeth; in general whenever you have a dog that chews a toy with a chipping rather than a grinding technique farther back in the jaw, it’s likely the item will be destroyed and potentially ingested.
Planet Dog has a line of rubber like balls that I have heard good reviews of from other Bull Terrier owners. To me, they do not look like they would stand up to Anna’s “chip and destroy” chewing style, so I have not tried them.
Rubber Balls with Holes
Another type of rubber ball is the open design “Hollee Roller” along the lines of Buckminster Fuller’s “Bucky Ball” which is surprisingly durable for many hard chewing dogs, I think this is because they don’t offer a firm surface for chewing. Anna and I play a ball volley game every morning with the smallest HR ball and they will typically last for as much as a year before enough of the connecting pieces get chewed to where the ball no longer bounces.
There are also stuffable Kong biscuit balls, the holes are a bit too large for any but the largest biscuits to stay in and they are quickly removed. They can be used to entertain hard chewing dogs for short periods while well supervised, but are not recommended for long term or unattended play.
Balls with items inside, such as bells are not recommended for two reasons, if the ball is breached the item can easily be swallowed, and there are instances of dogs creating a vacuum which sucked their tongue inside these balls, causing serious injury. This type of ball has been recalled by the manufacturer but may still exist in dog toy boxes as they’ve been around for a long time.
REALLY hard balls
The only truly indestructible (Anna proof) ball that I have found is a hard plastic ball made by Horseman's Dream's Jolly Pets division called the Jolly Ball. The smallest size is slightly larger than a tennis ball and can be roughed up and even punctured, but does not come apart when subjected to intense chewing. The larger sizes can entertain dogs for hours as they are too big to be picked up in the jaws easily and will be nose-punted around the yard (or house!) I do not recommend them for Bull Terriers however as they surface gets rough and the inevitable head to ball contact usually causes a badly roughed up face. I’m not sure if dogs with more conventionally shaped heads sustain the same kind of damage. A similar product is the Boomer Ball, but Jolly offers smaller ball sizes.
In the past Nylabone manufactured a solid nylon dog ball which was also close to indestructible. It also was subject to getting surface abrasions as it was chewed, but unfortunately its weight made it dangerous to throw and extremely noisy when played with indoors. I suspect these characteristics led to its demise.
Balls with sound
I have acquired a couple of Babble Balls, which make a variety of sounds when they move. These fascinate my dogs and are very hard to chew; the ones I have stand up well to the amount of chewing that they endure before the sound drives the humans crazy and we put it up. I think the sound discourages chewing as well since the dogs will often stare at the ball while it is talking. I have two Babble Balls which amuse us by talking to each other in the closet if someone slams a door hard or otherwise shakes the house enough to activate them.
Occasionally you will see a ball that is made entirely out of some kind of rope tied who knows how into an elaborate knot like an enormous knotted button. These are actually quite durable and I have a small one that has a tug rope attached that I use as a show ring toy. They can be chewed up like other rope toys, but since there are no loose ends (in the beginning) this can take quite a while. The drawback, particularly with those made of cotton rope is that they absorb slobber very effectively and can develop a bad odor. This is accentuated by the fact that the rope ball dog toy, being such a dense shape, does not dry well, which also makes it hard wash and especially to dry effectively.
Generally not recommended for dogs, leather balls like American footballs and soccer balls can be punctured and eaten, other large inflatable balls are also easily punctured, although not quite so attractive to consume. Never let a dog have a ball small enough to block the back of the throat, this can be lethal. Golf and ping pong balls should be kept away from dogs at all times.