Diseases have consistently been a major limiting factor to profitable production. Some diseases result from egg transmission or organisms through the use of infected breeder flocks. Other diseases are brought into the poultry house by vectors like wild birds, rodents, parasites, and even the poultryman. Disease results when exposure combined with the virulence of an organism is greater than the resistance of the host. Disinfectants reduce the exposure time and number of organisms.
Vaccines help build the natural resistance or immunity of the birds.
Medications and drugs help battle the disease organisms after they have overwhelmed the birds' natural defenses. Most diseases can be eradicated from the poultry flock by applying the basic principles of hygiene and excellent sanitation. Other diseases are not easily eliminated, but can be controlled by proper use of disinfectants and sanitizers. If not controlled, the potential for microbial contamination and spread of infectious diseases in the flock is always a threat to the success of any operation. Sanitation is a rather simple word, commonly used in our daily conversations to refer to the establishment of environmental conditions that are favorable to health.