gen2: dragons do not consume agenothree, they take in firestone given by us riders carried in a pouch while a dragonback fighting thread, they chew it, it gets digested in a ruminated way and belch forth fire...that's the long and short of it. Of course gold queen dragon riders use agenothree in a flamethrower chemical kind of way, for to use firestone in golds would make them sterile and could not reproduce.
Sorry don't advocate slaying, just wanted to set a wrong to right on facts. Carry on.....