Put the summary of the bug you're having here
Hi, in my survival world for Minecraft 1.11.2 I named a sheep with a name tag. After hours of game play I found that the named sheep disappeared without any cause such as being killed by a hostile mob. similarly, I dismounted a horse that was tamed and equipped with a saddle disappear as well. In regards to the sheep, the bug occurred right after I was trying to lure four more sheep with wheat to the vicinity of the named sheep from several chunks away. I got fed up with them not following and killed them and went into creative mode and used a sheep spawn egg and spawned four new sheep close enough to the named sheep for it's chunk to be loaded. As for the horse, I had just returned from the same area I was trying to lure the sheep from. There is a village in the loaded chunk area as well. That is about all the two events have in common.

What I expected to happen was...:
Describe what you thought should happen here
My named and tamed animals not to de-spawn

What actually happened was...:
Describe what happened here
They de-spawned
Steps to Reproduce:
Put a step by step guide on how to trigger the bug here
Not sure exactly how the bug was triggered, but this is my idea.
1. ...Spawn different entities including horses
2. ...Tame the horses
3. ...Name the other entities
4. ...Ride horse far enough to unload the chunk with the named entities
5. ...Return to chunk with the named entities
6. ...Dismount horse and see it is still spawned
7. ...Take spawn eggs out of creative inventory and place down, checking to see if any named entities de-spawn.
8. ...Repeat steps 4 and 5 and see if named entities are still spawned
9. ...Repeat in both creative and survival modes.