Like human beings, chickens are vulnerable to all sorts of illnesses and conditions. Bacteria and viruses may cause some of them while others are fungal in nature. Among the conditions that can trouble these birds are chicken eye infections.
Bacteria can be responsible for many different eye infections in chickens. For example, salmonella bacteria can cause purulent conjunctivitis, which is marked by pus and inflammation of the inner part of the eyelids and the membrane that lines the eye. Salmonella bacteria can also cause ophthalmitis, an eye infection marked by inflammation and the discharge of pus. Often, chickens are exposed to these infections due to contact with other infected chickens or before hatching.
Sometimes, chickens develop viruses that make their eyes look infected. For example, a disease called avian pox is caused by a virus and presents with lesions that resemble blisters. These raised lesions typically form on the areas of the birds that aren't covered by feathers. They may form on the legs or the head, for example. These lesions can also develop around the eyes, making it difficult for the chickens to see. In some serious cases, this disease can even cause blindness. Fortunately, the affected bird's eyesight is typically restored once the lesions are gone.
Fungal infections often cause eye problems in chickens. One mold that commonly leads to problems is called Aspergillus. It typically causes infection of a chicken's respiratory tract, but it may affect the eye and brain as well. When it affects the eye, it causes yellow plaques to form under the chicken's eyelids. This leads to inflammation and serious eye damage. Often, birds are exposed to fungi in the hatchery, though exposure can come from food and litter as well.
A chicken's eye may become infected because of an injury. For example, if a chicken is pecked in its eye or hit with a piece of equipment, bacteria may be introduced and cause an eye infection. Sometimes chickens even irritate their own eyes when they are sick with other types of illnesses. If a chicken has a respiratory illness, for example, it may also develop conjunctivitis. Then, the chicken may rub its eyelids in reaction to the discomfort caused by conjunctivitis. This can lead to further inflammation but doesn't typically cause permanent eye damage.
Chickens are often treated with antibiotics when they have eye infections. Some antibiotics may be applied in ointment form. However, other antibiotics must be ingested in tablet or pill form, and there are some that can be mixed with water. Take an ill chicken to a veterinarian if possible. If an infection is contagious, separate the sick bird from the other chickens to avoid spreading the disease.