Dog is bleeding internally from the leg what is the cause?

Posted by brow4636

3 year old male Greyhound went in for a routine dental, came back next day had a bruise the size of my palm on back leg. Was on deramaxx, took him off. Leg has swollen to twice the normal size in two days with blood and it is starting to move onto the other back leg. He has blood in his urine and stool, but no red blood cells in his urine if that makes sense. Have done blood work, urinalysis and everything came back normal. My doctors are stumped. What gives