The hard nylabones can also be broken off in chunks - my dogs have thrown up several bits of it after chewing on them.

Also, one of my dogs broke a tooth, either on a hard nylabone or a cow hoof. We discussed the issue with our vet, who feels strongly that the hard nylabones should be banned from the market, as they are hard as rock and often break dogs' teeth. If your dog is AT ALL an aggressive chewer, hard nylabones are not good for them.

I use the regular, liver-flavored nylabone gum-a-bones for my aggressive chewers - always supervised. If they chew a piece off, I take the piece from them and throw it away. They have to have SOMETHING to chew on, and hard nylabones are too hard, booda bones and nylabone fruit/veggie bones are gone in mere minutes, rawhide is not safe in large quantities, and galileo bones and sterlized bones are also much much too hard.

I give nylabone gum-a-bones, the occasional rawhide chip and raw beef knuckle bones (never cooked/boiled, because cooked bones become too hard, and too brittle -they can splinter and get stuck in dogs' intestinal tracts). My dogs need something to chew on, by nature, so I feel that these are the safest options, after much research and discussion with animal experts.

Every negative nylabone report I've ever read seemed to be associated with the nylabone dental bones - 'dental dinosaurs,' etc... the gummy bones that are covered with those sharp points, "to clean teeth." If a dog swallows a chumk of that pointy plastic, the points can become entangled in the striated walls of the digestive tract, and cause blockages, severe pain, and sometimes death. (I do NOT give the dental bones to my dogs!)