wound that wont heal

Question
My dog has a wound that will not heal. It continues to just get deeper in his shoulder. Now it has black tissue around the wound (and a small spot of black int he wound) - what I suspect is necrosis. I don't see inflammation or infection, but cannot make this heal and now it has the black tissue. I need some advice.

Answer
First, how did he get this wound? Is it a bite wound or from a foreign object or is it somewhere he lays on it all the time?

If it is the latter, then he has a bed sore not a wound and they won't heal without debridement and suturing. No wound that is necrotic will heal without some cleaning (debridement) and suturing and most likely antibiotics.

You need to take this dog into a vet and get this wound taken care of before it becomes gangrenous and he loses leg or worse.