Anatomy of Bedtime

When my boyfriend and I go to bed, the general outline looks like this:


The bed is a double and has ample room for both of us.  Generally, when we fall asleep, it’s quite comfortably and with plenty of room to stretch out.

However, come the morning, the outline looks more like this:


Somehow, during the night, a 23 pound dog manages to move 350 pounds of human onto half the space it started in.  Does anyone else have this issue with their Shiba(s)?  If we got another Shiba, would we be evicted from the bed altogether?