I'm running a 1.8 server and have noticed I has started to crash very frequently due to watchdog as the server is becoming very laggy.
I first noticed the issue when I was moving my items to my new base with donkeys. I was moving my stuff and my wolves with me when the server crashed. All 9 of the donkeys and all 5 of my wolves had vanished when I logged on I searched for ages and could not find them. I Had the same issue earlier today where my horse disappeared(luckily I had removed the saddle, but not the armour) and there was then two of the horse I was trying to tame at the time.(I know there is already an issue for that bit though)