Foxes not dropping items on death

A fox took a precious emerald from my inventory. I was pretty upset about this so I killed it. I could see the emerald in its mouth, but when the orange fella died (RIP Steven) the emerald was not dropped! I could not replicate this as every time I spawned in a new fox, it just ran away. I am vey sad for the loss of Steven the Fox and my emerald. Please look into this so that it will never happen to anyone else.