What dose it mean when a puppy has blood in there poo as I'm really worried about my 9 week old puupy, he tried some meat about 3 -4 days ago and has had the runs ever since and now I've noticed traces of blood in his poo when he goes

There could be many reasons as to why your pup has blood in his stool:
- Digestive tract problem
- Intestinal Parasites
- Colitis

*** Bring your dog to the vet, and they will be able to tell you what's wrong.