Some diseases can cause mild inflammation in the chickens but your flock will survive. Other infections can kill all of your chickens because of the severity of the disease. Coryza can kill our chickens because it can transmit from one chicken to the others. Because the pathogen can move from one chicken to another, the transmission is high.
Even though both injury and Fungal infections can cause abscesses the most likely course when a chicken gets an abscess near the yey is Coryza.
Coryza: Causative Agent And Transmission Route
Bacteria or viruses are responsible for most of the diseases in chickens. A bacteria called Avibacterium paragallinarum is the causative agent for this disease. This bacteria can enter the chicken by physical contact with other chickens.
Once it enters the chicken, it can start growing inside the respiratory tract. It will divide and produce chicken abscess near the eye. Chicken with infection can transmit it to others by physical contact. There are some other means this disease can spread also.
The bacteria can enter the water if an infected chicken is drinking from it. When the other chickens will drink the same water the bacteria enter the other chickens also.
Some chickens that do not have an active chicken abscess near the eyes can also transmit the disease because these are carriers. Carrier chickens do not have symptoms of the infection but bacteria is present inside the chickens.
These chickens can also transmit the disease at the same rate as the chickens with active infection.
Coryza symptoms and clinical signs
You cannot diagnose a disease if you do not know about the signs and symptoms. In the case of Coryza, you will not see the symptoms until the disease has progressed.
At the early stages, there will be no signs as the chicken is only the carrier without infection. At later stages, the infection can end with mild symptoms or it can go severe.
In case of mild symptoms, the chicken will only get some inflammation in the sinus area. The chickens can reduce egg production by 40% due to depression caused by this disease. The mortality rate of Coryza is 20%. In case of severe disease, the chicken can get severe inflammation in the sinus and mandibular area.
You may see the chicken abscess near the eye in severe cases. In some cases, the eyes of the chicken are closed due to the adhesion of the pus. The body temperature of the chicken may also increase due to infection.
Giving healthy food and medication is essential for the treatment of the disease. Some birds may respond to antibiotics. The mortality rate is 20% but it can decrease by using the Bacterin.
We can use two standard doses of this antibiotic to reduce the mortality in the chicken. There are some other antibiotics also like Erythromycin and Fluoroquinolones.
These antibiotics have shown promising results in reducing mortality due to Coryza.
Prevention and control
Prevention is better than cure in the case of Coryza. You can prevent the disease before it starts by vaccinating your chickens. The vaccine is available for Coryza disease. It can prevent infection. You can also prevent the infection by giving a healthy environment to the chickens.
It is better to keep monitoring the chickens for any signs of Coryza disease. If you see any signs in chickens, it is better to separate the infected chickens and start treatment in others.
If the infection has already started, you can control it by using antibiotics. In some cases, there is no choice but to cull all the flock present at that time and disinfecting the area before putting another flock.
Other diseases to consider (differential diagnosis)
When you see pus around the eyes of your chicken, you should not conclude that it is Coryza disease. It is better to go for PCR testing to confirm the disease before culling the flock.
An injury to the eyes of the chicken can also cause pus around the eyes. Some viruses can also produce pus in the eyes of chickens because the viruses can cause conjunctivitis.
Fungal infection in the eyes of chickens can spread quickly and show the same pattern as coryza. In the case of other diseases, you may not say a 40% reduction of eggs and 20% mortality. The chicken body temperature will also not elevate.