Avian influenza - A (H5N1) is a type of virus that causes highly infectious, severe respiratory influenza disease in birds. It also infects mammals rising concerns about its re-assortment and increased virulence. New strains with mutations have been making the virus more pathogenic. The more likely source for disease outbreak is from dairy cows or chickens that are infected. This presents a considerable source of economic detriment for both agricultural producers and the food industry. Hence, a concise overview on H5N1 to enhance the understanding of its infection for adequate disease combat and management is relevant.