The Doctor watched in horror, not sure what to do. He mentally went through all the items he had on his person, and none of them were suitable for such a situation, but Gabriel's gun was right there...

He made a grab for the rifle, shifted his position and braced the thing against his shoulder, then fired. The shot hit the beast square in the side, and the Doctor turned and fired towards the other cat. The first missed, but the second caught the thing in the chest, good enough to down it.

Lowering the gun, he lifted his hand to rub at his shoulder, silently cursing his age.