Coronavirus infection is the major cause of mortality of neonates as well as adult of many domestic animals, companion animals and millions of human in developing countries besides causing major economic losses. Concurrent infection with secondary pathogens may augment the disease severity. Coronaviruses do not necessarily observe species barriers. Although respiratory and enteric tracts are common targets for coronaviruses and are not limited to particular organ, target tissue and affects all organ including the nervous system, immune system, kidney and reproductive tract. This book describes vividly about the diagnostics of corona viral infections so that better prevention and control policies can be formulated.