Thanks guys! Yeah, I shot those with the kit lens, but I have another lens:
"55-200mm f/4-5.6G IF-ED AF-S
DX VR Zoom-NIKKOR Lens"

Not too sure how that all works together. Not even sure if the latter lens will help me shoot action shots. Sarah?

Thanks for the info on shutter speed/aperture. I did bump up the ISO but it didn't help too much. I think it's just mostly a matter of understanding my camera's settings and, as always, diligent practice. At least I have lots of opportunities to shoot the pups though!