Infectious Coryza is a bacterial disease that affects upper respiratory tract of chicken and manifest itself with closed eyes, discharges from nostrils and death. This is the culprit responsible for high mortality mostly seen in chicks. It is not the only disease that affects eyes but it is a killer disease and most chicken farms are suffering from it in Namibia.
Poultry being a niche inteprise it is upon that fact that farmers be given information. This bacteria affects other birds like quails and pheasants as well. Therefore poultry farmers need to know signs of Infectious Coryza in order to control its incidences on farms.
All birds act as reservoirs and all ages are susceptible. It takes about 1-3 days from infection to the first clinical sign appearance and the disease situation takes about 2-3 weeks. The disease can affect 70% of the population especially if birds are kept in poorly ventilated houses. Despite this disease being deadly and affecting all chicken age groups, death commonly occurs in chicks.
This disease spreads through direct contact, inhalation of infected droplets, as well as contaminated feed and drinking water. Keeping a large number of chicken in one house, exacerbates its rate of transmission mostly in poor ventilated houses. This is due to the fact that, there is no enough air flow in the house. Poor ventilation also causes stress in poultry as a result of ammonia accumulation which leads to a decrease in eggs production.
What do you see in infected birds?
Infected birds show common signs like purulent ocular and nasal discharges which cause loss of sight and difficult breathing. Other signs like swollen face, sneezing, loss of condition, depression and diarrhea can also be seen. Chicken usually have closed eyes due to eyelid adherence and when you open the eyes a yellowish hardy exudates (caseous material) may be seen. Swollen wattles can be seen in roosters.
Not all chicken with aforementioned signs have Infectious Coryza, other diseases may present with same clinical signs and need to be differentiated by your nearest veterinarian. The confirmative diagnosis can be done in laboratory and this is very important for accurate treatment.
The following diseases present themselves like Infectious Coryza: Mycoplasmosis (Chronic respiratory disease), Infectious laryngotracheitis, Newcastle, Infectious bronchitis and others. This is why your veterinarian is of utmost importance to differentiate it from others. It is therefore very crucial that right diagnosis is made to enable appropriate treatment.
Different antimicrobials can be used, however their effectiveness depends largely on the right use, in terms of reconstitutions and duration of treatment. Therefore the consultation of a Veterinarian is important for appropriate antimicrobial prescription. Hence it is advisable to consult them before buying any antimicrobial.
Control and prevention
This should be a focal point for all farmers (Prevention), because prevention is better than cure.
Make sure you have an up to standard biosecurity measures in place on your farm, which includes but not limited to vaccinating (injectable) your chicken, changing clothes before going into your chicken house, avoiding sharing equipment or disinfect them before use, keeping away other chicken if you have free roaming chicken on your farm and practicing immediate isolation of the susceptible chicken coupled with appropriate diagnosis and treatment.
Those aren’t the only measures you must put in work, some agents can also be used to decontaminate drinking water, therefore your local veterinarian is the best person to advice you.
Article written by Dr A. Wed Nelson (firstname.lastname@example.org BVM, Unam), and Dr E. Junias (email@example.com BVM, Unam)