Acute Hepatic Failure in Dogs. Acute hepatic failure is a condition characterized by the sudden loss of 70 percent or more of the liver's function due to sudden, massive, hepatic necrosis (tissue death in the liver).
Key Points. Secondary (acquired) immunodeficiencies are much more common than primary (hereditary) immunodeficiencies. Primary immunodeficiencies can affect humoral immunity (most commonly), cellular immunity, both humoral and cellular immunity, phagocytic cells, or the complement system.
In brief: No worries. The only difference between the flu shots is the dose: children under three get half the adult dose. That means a child will get an adult dose the day after his 3rd birthday, whereas the day before that birthday he would have received the smaller dose--half.