The bacteria responsible for such diseases include Ornithobacterium rhinotracheale and E. coli, while the viruses include Lentogenic Newcastle disease virus and the Avian pneumovirus. The mortality rate from these respiratory diseases in chicken may be 5-10 percent, sometimes even high if the condemned birds are included. Below are some common respiratory disease in chickens and their symptoms.
1. Mycoplasma Gallisepticum Infection
Mycoplasma Gallisepticum (MG) is a bacterium responsible for the onset of the chronic respiratory disease in chickens, and also infectious sinusitis in other poultry and birds. It is transmitted through carrier eggs, with most commercial flocks being free from this bacterium. However, it can be introduced to a flock if it is mixed with carrier flock.
Symptoms of Mycoplasma Gallisepticum
There are a number of obvious signs and symptoms of MG. Others are not so obvious and especially in young flock. Sometimes, the chicken may also show no outward signs at all. Some of these signs and symptoms include:
- Presence of a sticky nasal discharge
- breathing difficulties
- face swelling
- Presence of a foamy secretion in the eyes
- lowered appetite
- lowered body weight
- A decrease in egg production
In young poultry, you may notice rattling, sneezing, and sniffling. There is also some stunted growth of the chicken when they get infected with MG. As the infection gets worse, you may notice wattles and a blue comb, meaning that there is very limited oxygen supply to the tissues. This is a strong indicator of a severe infection that compromises the chicken's life.
MG bouts are commonly triggered by weather changes, a change in the home of the chicken, poor diet, lack of water, and any other factor that increases stress in the chickens. Avoiding stress for your poultry may reduce the chances of this infection.
2. Avian RhinoTracheitis (ART)
This is a viral disease, also referred to as the swollen head syndrome, SHS, thick head, or facial cellulitis. It is caused by a Paramyxoviridae family pneumovirus. The mortality rate from this disease is anywhere between 1-10 percent.
Signs and symptoms
- Swollen sinuses
- decreased appetite
- Swollen tracheitis
In broilers and their breeders you may notice red swollen eyes, sneezing, face scratching using the legs, head swelling that is progressive, and lowered egg production in the breeders.
3. Infectious Bronchitis (IB)
This is one of the most common chicken infections caused by a Coronavirus which varies antigenically. The depth of this infection varies depending on a number of factors including the birds' age, virulence of the virus, vaccination done prior to infection, maternal immunity, and presence of other complicating infections. The mortality rate from this disease is anywhere between 0-25 percent.
Signs and symptoms
- Loss of appetite
- Wet litter
4. Infectious LaryngoTracheitis (ILT)
This is a viral infection in chicken caused by a herpesvirus that varies in pathogenicity. It has a mortality rate of 10-20 percent but this may sometimes be as high as 70 percent. The causative virus can be spread through air and is highly resistant when outside a host. However, it is quite susceptible to disinfectants. Mixing and moving a flock is one of the major predisposing factors.
Signs and symptoms
- Reduced egg production
- Discharge from the eyes
- Nasal discharge
Treatment for respiratory infections and diseases in chicken
Most of the infections caused by bacteria can be treated using antibiotics. However, for the viral infections and diseases, there may be no cure. All you may need to do is to control the secondary bacterial infections. Some common treatment options include use of Agrimycin®-343 Soluble Powder , Tylan Soluble Powder, and Lincomycin-Spectinomycin. Sodium salicylate may be used in acute infection of IB, but only when permitted.
The bottom line is that you should keep your poultry houses clean and well ventilated to reduce possibilities of infection. Make sure to also vaccinate your poultry on time, where applicable, and also use broad spectrum antibiotics and sulfonamides to treat bacterial infections. This will help you easily get rid of respiratory disease in chickens.v