It is important to know about common chicken illnesses if you are keeping chickens. If you are aware of the common illnesses and their symptoms you can head of any illnesses as soon as possible. If you don’t stop any illnesses as soon as you can then it may spread to your entire flock and you may need to get a new flock and completely clean the area in which you keep chickens, which can be pricey.
Most common chicken illnesses affect the respiratory tract; the air sacs, lungs and air passages. Because chickens tend to be kept in small spaces with many other chickens these diseases tend to spread quickly. These diseases affect all forms of poultry not only chickens and can spread between types of poultry.
Fowl pox, also called sore head, avian diphtheria and bird pox, can affect all chickens no matter their age. Fowl pox comes in two different forms, a dry form and wet form.
The dry form has wart-like lesions that take about two weeks to heal. These lesion form on unfeathered areas.
The wet form has lesions that are like cankers and are found in the trachea, larynx, pharynx and mouth. These lesions can obstruct the air passage causing breathing problems. Chickens can have both forms of fowl pox at the same time.
Fowl pox is spread by direct contact or by mosquitoes. It is a virus and can enter the blood stream through the skin, wound, eye or respiratory tract. Research has shown that once a mosquito is infected it carries the virus for its life. Some symptoms are retarded growth, unthriftiness and a decline in egg production. There is no treatment for the fowl pox but you can vaccinate for it if you notice symptoms quickly.
Newcastle disease is highly contagious and lethal. It is not currently found in the US poultry industry. Humans and mammals can also catch the Newcastle disease from chickens, though it only causes conjunctivitis. The symptoms of Newcastle disease are hoarse chirps, nostril watery discharge, facial swelling, paralysis, labored breathing, twisting of the neck, and trembling. Depending on the severity of the disease the mortality rate ranges from 10 to 80 percent.
Newcastle disease can be transmitted by contaminated shoes, visitors, dirty equipment, wild birds, crates, feed sacks, tires, feed deliverers, and caretakers. It can be passed on through to the egg. Newcastle disease has no treatment but antibiotics can be used to stop any secondary bacterial infections. There are vaccinations that can prevent this disease.
Infectious Bronchitis only affects chickens, though there is a similar disease found in quails. Other factors such as the age of the chicken, the environment, presence of other diseases, and the immune status of the flock all affect the severity of the infection. Symptoms include feed and water decline, eye and nostril watery discharge, labored breathing and chirping. If the hens are laying then egg production will sharply decline. Eggshells also may become rough and the egg white watery.
Infectious Bronchitis is very contagious and spread by infected dead birds, feed bags, infected houses, air, though the egg and through rodents. There is no current treatment and to prevent any outbreaks you should have a strong biosecurity program and use the available vaccinations.
Avian influenza has a mild of sever form and can infect all types of birds. A mild case of avian influenza will result in a loss of appetite, respiratory distress, decline in egg production, low mortality, diarrhea and listlessness. The sever form symptoms are facial swelling, wattles, blue combs, dehydration and respiratory distress. Additionally you may notice blood tinged nostril discharge, dark red and/or white spots on the legs and combs and any sudden exertion can cause death.
Avian influenza can last for a long time at room temperature and indefinitely in frozen objects. The disease is easily spread by inappropriate disposal of chicken carcasses and insects and rodents. There is no current treatment for avian influenza, but antibiotics and proper nutrition can stop any secondary infections from occurring. Even if your flock has recovered they can still spread the disease.
There other disease that effect chickens that are not respiratory based and are bacterial diseases and not from viruses. Some of these diseases affect all fowl while others only infect specific types of fowl.
Other chicken illnesses are infectious croyza, Infectious Laryngotracheitis, chlamydiosis, swollen head syndrome, mycoplasma gallisepcticum, mycoplasma synoviae, mycoplasma meleagridis, aspergillosis, marek’s disease, lymphoid leukosis, infectious bursal disease, avian encephalomyelitis, egg drop syndrome, infectious tenosynovitis, fowl cholera, omphalitis, pullorum, necrotic enteritis, ulcerative enteritis, botulism, and staphylococcus.