gatos Two black cats

This is a great idea for a photo but the cats are underexposed to the point that in those areas the detail is lost.  I would reshoot the image.  If you try to lighten the cats the dark areas would come out very noisy.  Light and darks are tricky.  If you light up the dark the whites could be too overexposed and the same problems with getting the whites right the darks would be too dark.