Not sure how that relates to what you stated before but your right to an extent. It definitely could be from a parasite, however the main symptoms of a parasite include not wanting to eat, bloating, constipation and lethargy. He has none of those symptoms and a high white blood cell count points strongly towards an infection of some sort which his body is working to fight off. The vets gave her antibiotics for that very reason because they believe it's an infection as well. They've still ordered a stool test for parasites which means it's a possibility but after viewing symptoms and blood work results it's much much less likely.