Although information is still coming out about Swine Flu , so far it does not seem to be as severe as Bird Flu or the flu that caused the Influenza Pandemic of 1918 ( also known as Spanish Flu ) , but it is much too early to predict whether it will cause the next flu pandemic . The main variants named using this convention are : Bird Flu , Human Flu , Swine Flu , Horse Flu and Dog Flu .