For Ivan A bully stick will last a couple of hours atleast. Raw hide hes not a fan of. Antlers, pigs ears, and bones forever, well atleast until Peewee steals it. Because Ivan views most chew things, toys or he ignores them. For peewee, Bullysticks last maybe 15 minutes, rawhides he won't touch Antlers a while because he usually chews on it for a bit, then Ivan comes out steals it and plays with it and looses it on him. Pig ears 5 minutes maybe. Its taken Peewee a little longer now days to chew things down. At 14 his teeth are starting to wear down. Bones maybe a day to 25 minutes depending on what kind of bone. Peewee ends up with most chew things around here, because Ivan doesn't get the concept of chewing things up. Heck, he debones(and eats the bones last) his dinner if he can.