I lifted his lip and looked at his gums. Instead of the bright healthy pink we like to see, Murphy's gums were very pale. His red blood cell count was about a third of what it should have been. If Murphy had been any more anemic, he would have needed a transfusion. No wonder he was lethargic.
Intestinal worms are a common cause of anemia in young puppies.
The staph infection and, Judging from Murphy's history, malnutrition may have contributed also. They took him home with an antibiotic that should clear up the infection and some B-vitamins and iron to help Murphy rebuild his supply of red blood cells. We will reexamine Murphy in a week. By then I expect to see his red blood cell count climbing up towards normal and the infection should be healed. They will bring in a stool sample to make sure any worms he had are gone.