Well if you can get the doggie to stand still while you lite the scene that's all well and good but realistically I think these shots were just too dark for you cam's auto settings. Does that cam display a histogram after each shot? If it does learn to use it. It will tell you if your shot is exposed properly. And learn your manual settings if you can't get there in auto.
Here is the histogram for the original shot:
You can tell it's under exposed by the black levels being piled up on the left side.
Look at the histogram after I adjusted the levels:
I pulled the whites slider down and slid the mids over to enhance contrast and lighten up the image. I actually like walt's version a bit better, I over did it to show you the effect. If you shoot in RAW it's even easier to fix.
But if you watch the histogram in camera you can get the shots exposed properly and not need any post processing.