Elevated white blood counts are usually indicative of infection. If he has a bacterial infection, that can account for an elevated WBC. What type of infection does he have?
Jaundice is usually very serious. However, the treatments and prognosis depends on the degree of jaundice and the cause of the jaundice. Liver disease can cause jaundice or certain types of anemias can also cause jaundice. The cause and treatment will depend on the etiology of the jaundice. Ask your vet to explain this further.
Anemia is a low red blood cell count and is often nonspecific. Certain infections, conditions, and diseases can be associated with anemia. The bigger question, is what is the underlying infection or disease that led to his jaundice and anemia?
Best of luck with your little guy!