One of the most common complaints of backyard chickens is snicking, sneezing and coughing. Birds can have a runny nose and foamy running eyes. In severe cases these birds can have swollen sinuses (presents as swelling around the eyes), stop eating and in extreme cases die.
Stress can cause an underlying disease to show. This could be extremes of temperature and humidity, high stocking density, being transported, being taken to a show and new animals being introduced to an existing/established flock.
Antibiotic treatment is usually advised. Usually given in water but in severely ill birds injections may be the best option.
Isolate birds from other healthy hens, given lots of TLC and give veterinary attention where necessary.
A simple blood test can determine which pathogens are involved. It is often the case that more than one is involved, the most common are:
Mycoplasma Gallisepticum: a type of bacteria which can cause respiratory disease in poultry. Often associated with swollen sinuses, sneezing and foamy watery eyes. It can infect the oviduct thus altering egg shell colour and quality and thus it can be transferred via the egg to chicks. Once infected a chicken is infected for life although clinical signs will regress with time and treatment.
Infectious Bronchitis (IB): IB is a coronavirus which causes sneezing, foamy eyes and swollen sinuses usually in young birds. However like Mycoplasma it can infect the oviduct again altering egg shell colour and quality but unlike Mycoplasma it doesn’t infect chicks via the egg.
AvianRhinoTracheitis virus (ART): a pneumovirus which causes swollen heads, swollen sinuses, sneezing and in severe cases nervous signs.
Infectious LaryngoTracheitis virus (ILT): a herpes virus that causes similar respiratory signs. ILT often leads to a plug of blood and mucus which can block the birds trachea (windpipe) leading to the bird choking to death. This virus like Myoplasma never goes away and can come back during times of stress.
The pathogens above are mostly viruses which will not respond to antibiotics but these viruses often damage the respiratory system sufficiently to allow secondary bacteria such as E. coli and Pasteurella to cause infection.
Tips to prevent infection:
- Minimise stress
- Ensure stocking density and ventilation are correct
- Buy in disease free birds from a reputable supplier
- Quarantine new birds for at least 3 weeks
- The Full Article: The Chicken Vet talks about Respiritory Disease in Chickens on poultrykeeper.com