Solid nylon is crazy tough, and it's the go-to material for pleasing the strongest and most determined dogs in our pack. When a dog destroys everything, we find that solid nylon offers them the most challenge. It's hard and resilient, but still softer than your dog's teeth (tooth marks are good and normal!) – perfect for the dog who likes to really settle in and gnaw on something for a while.
Because it's so hard, we don't recommend it for vigorous activities, just because tossing a nylon toy is a great way to break your TV (we've learned this the hard way in our own homes). Nylon is pretty darned hard – that's why we make toys out of it! – and we've noticed that sometimes determined chewers can cause chips or cracks in teeth if the dog doesn't take it easy. We don't want this to happen, so if your dog is especially aggressive while chewing, you'll want to limit how much time they're able to spend with the nylon toys.
The nature of solid nylon also requires careful supervision because a very strong dog can break it eventually, causing potentially-sharp fragments and splinters. You really have to work to make it happen, but it's something to watch out for. If these sharp edges and burrs develop on the main body of the toy, you can use sandpaper or a file to smooth them down safely. Discard any piece that your dog breaks off the main body of the toy. Always supervise your dog when they're chewing on anything, including solid nylon toys.