The grave was sprayed with dog blood. Is the feng shui in that place okay?

Nothing, the geomantic omen of the Yin House mainly depends on the atmosphere, followed by the terrain, and finally the details such as orientation and furnishings. Dog blood has no effect on these, but I feel bad when I know it. Don't worry, it's not destructive to Feng Shui. On the contrary, dog blood is a pure natural organic biological fertilizer, which can fertilize the corrupted land and increase the vitality here.