Horse Disappears when in the pen you place it in. Log back off and on and it is standing in the place you put it again

Its hard to explain what happens but I know that it is a bug.

What actually happened was...:
The horses were standing in their pen at the stables and five to ten minutes later they disappeared. I logged off and back on and they were back in their pen

Steps to Reproduce:
1.Stand close to where you put the horse in a pen
2. After placed in move away from where it is
3.Check back about 3-4mins and the horse disappears
4.Log off and then log back on
5.The horse is back in the pen