Dog blood or human blood is difficult to clean up once it sets in after 24 hours. Call or stop by the police station and ask for the name and number of a company that cleans up places after a person has died there. They exist and can probably help you much more than any of us can.
Failing that, I've never had to do this but I'd cover the spot in potato flour for 48 hours to pull the moisture out and then hit your hardware store for pet stain remover which is enzyme based and let that soak into the wood. It should go in easily since the wood is now "thirsty". Now cover in clean potato flour again for 48 hours to pull the moisture out again, and hopefully a lot of the enzyme and blood with it, and repeat as many times as necessary to get a feel for if the enzyme treatment is working.
Follow it all up with a good deck stain.
James
DIY Home Center
Failing that, I've never had to do this but I'd cover the spot in potato flour for 48 hours to pull the moisture out and then hit your hardware store for pet stain remover which is enzyme based and let that soak into the wood. It should go in easily since the wood is now "thirsty". Now cover in clean potato flour again for 48 hours to pull the moisture out again, and hopefully a lot of the enzyme and blood with it, and repeat as many times as necessary to get a feel for if the enzyme treatment is working.
Follow it all up with a good deck stain.
James
DIY Home Center
