No more chickens should be brought onto the farm for 2-3 weeks. While the frequency and severity of the disease can be reduced by vaccination or antibiotic treatment, the flock will still have disease outbreaks periodically. Any bird from an infected flock which is taken to another farm, market, or fair will probably infect other birds. The only way to prevent the disease is to not buy or handle infected birds. It is best to avoid buying chicks which have been on the ground or around older poultry since they could have been exposed to coryza or many other diseases.
Older birds are more likely to be disease carriers.
This prevents mixing birds of different age groups and allows disinfection of the equipment and buildings between groups of birds. A coryza infected flock will always be prone to disease outbreaks and will always be a threat to other people s flocks. The best course is to eliminate infected birds, disinfect the farm and buy clean birds.