My dog is making me sad

If you haven't met, let me introduce you to our dog:

Taylor

While we were back east, a coworker of mine and her family was taking care of our sweet dog.  The coworker's family has a dog and 2 kids who were SO EXCITED about taking care of my puppy.  Their excitement made it easier to leave her.

We did the dog exchange at the office.  My coworker sent me updates during the trip to let us know everyone was getting along well.  I missed my dog.

So I was super excited to come to work and see my puppy.  When I get here, did my dog RUN UP to me and jump for joy?  Not really.  She walked over and let me pet her and then went right back to my coworker.  Then later when my coworker brought her food bowl and stuff into my office, Taylor whined.  Like she was disappointed to not be going home with my coworker again.

And then she watched my coworker leave at lunch and stared out the window.  In my opinion she was waiting for her to come back.

I have been replaced.

This isn't good for my ego.

Sad.  :(