This is a bug that causes a bounce/teleport when I walk into the hitbox area of my tamed and name-tagged dog. The bounce is directly away from the point of contact. Rotation of player and dog does not matter (shown in second video).

https://www.youtube.com/watch?v=pMC9xahYLa4

It was first noticed on the Half Slab light blocking platform I made up at Y=85. It happens with the dog sitting or standing, on the crafting bench, or on the slabs.  

https://youtu.be/ivrVxf7rFRY

I was able to replicate on the lower level covering of other glass blocks and half slabs. The dog does avoid following me onto the half slabs. I will continue testing tonight to see if this is a transparent block issue overall, dependent on Y value or another way that I can replicate in different areas inside or out of Spawn chunks.

Edit:

This is now showcased by Docm77, they are also in a high up level over an open space deep to bedrock and near a mob farm. https://youtu.be/1015wWvDUmc

ilmango just got Schwoomed at 19:45 and teleported outward

https://www.youtube.com/watch?v=poK7CzjWsGM