The case of the amputee dolls

We recently solved a mystery in our house. It started a couple weeks ago when K. noticed that her tiny little Cinderella doll was missing her right hand. I thought she would've been very traumatized by this, since she loves those little dolls. But she didn't seem to mind too much.

Then a few days later, one of her Barbies turned up with the same affliction- a missing right hand.

At this point we had a definite suspect in mind but couldn't prosecute anybody until we had some concrete evidence, or caught the offender in the act.
The next day, yet another Barbie was discovered with a missing right hand. However, this one was not a clean cut amputation like the other two, the edges were ragged and rough. Which confirmed my suspicion that I had the right suspect in mind. Yet I still needed to catch them in the act.

Then a day or so later, there was finally a break in the case. I was at my desk and out of the corner of my eye noticed our puppy, Jasmine, had something in her mouth. She kept spitting out and then picking the object back up and chewing it. I went over, opened her jaws and fished the object out. This is what I found:

I was slightly disturbed by the sight of the tiny little hand, but we finally knew for sure who was dismembering the dolls.
So we reminded K. once again that she needs to pick up her toys when she's done playing with them. But yet today, I saw this:

I wonder why it's always the right hand?