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What is Infectious Coryza in Chickens, and How Do I Prevent It?

A hand holding a chicken with infectious coryza

Raising chickens is a rewarding, profitable, and exciting experience. While there are many positive attributes to having chickens in your backyard or farm, it doesn’t come without its share of issues. One of the most critical issues chicken farmers want to address is how to keep their flock healthy and prevent diseases.

Coryza in chickens is one disease of which you should be aware. Chickens with this infectious disease will have what appears to be an upper respiratory infection. The good news is that this acute respiratory disease of chickens can be treated, and most birds will recover. However, older birds or those with weaker immune systems may not be so lucky.

Learn more about this disease in today’s blog post, or contact us for questions about raising happy, healthy birds!

What Is Infectious Coryza?

Infectious coryza is a fairly common infection of the respiratory tract in chickens. It’s sometimes called roup, catarrh, pip, or IC. It is caused by the bacterium avibacterium paragallinarum, once known as haemophilus paragallinarum. It appears as a severe cold but can affect your farm’s sustainability and egg profitability.

It affects chickens worldwide, and in the United States, it primarily affects pullets, laying hens, and occasionally broilers. Coryza in chickens is more common in commercial flocks in California and the southeastern states. Chickens of all ages can get coryza but become more susceptible with age. The incubation period (the time between exposure to when systems and signs show) is one to three days, with the disease lasting for two to three weeks.

How Can You Tell if a Chicken Has Coryza?

A chicken with swollen eyes suffering from coryza

Some of the clinical signs that a chicken has coryza include:

  • Decreased activity
  • Foul-smelling nasal discharge
  • Sneezing
  • Facial swelling
  • Watery eyes
  • Diarrhea

In mild forms of the disease, it may be hard to spot the signs. The facial swelling may only be slight, and the chickens may not be as active as normal. However, as the disease progresses, one or both infraorbital sinuses will continue to swell, preventing the eyes from opening completely. In adult birds, especially males, the swelling may spread to the jaw and wattles and last for 10 to 14 days.

What Are the Common Causes of Coryza in Chickens?

Coryza in chickens is caused by bacteria that can be spread from bird to bird. Carrier birds with this bacteria spread the disease through direct contact with other birds, airborne droplets, and contaminated feed or drinking water. Transmission cannot occur via eggs, so if an infected bird lays an egg, it won’t have the disease. However, chickens with this disease will likely have decreased egg production.

How Do You Treat Coryza in Chickens?

If bacterial cultures come back positive for coryza or you highly suspect your flock may have the disease, you must isolate the infected chickens. Some farming operations choose to move all the chickens of the same age out to isolation so that they can all be exposed to the pathogen and develop some resistance to it. In the meantime, the facilities are deep-cleaned and disinfected before new, healthy birds are introduced to the environment.

It would help if you immediately administered antibiotics to the chickens via drinking water until you can get medicated feed. Antibiotics, such as erythromycin and oxytetracycline, can help treat infectious coryza in chickens. Your veterinarian will be able to prescribe the right antibiotic for your birds. Once recovered, the chicken can still be a carrier and infect other birds in your flock.

Is Coryza in Chickens Curable?

If you spot coryza in chickens early enough, you may be able to get rid of the disease with antibiotics, as mentioned above. However, it’s best to begin the isolation and identification of the disease early to not spread it further on your farm. If you do not isolate and treat the disease in the chickens, it will continue spreading until your entire flock is infected.

The mortality rate is around 20% in most flocks. For older chickens, ones with compromised immunity, or ones with another type of infection, coryza can be deadly. It may be more humane to cull those chickens rather than let them suffer with coryza and eventually die. Additionally, other birds on your farm, such as ducks, quail, or pheasants, may not survive this disease or overcome it as quickly as chickens can.

How Can You Prevent Coryza in Your Flock?

Sound farm management and biosecurity practices are essential to prevent this upper respiratory disease. Once the infected birds and those near it are removed, and the coop is disinfected, replacement birds can be obtained from clean flocks (but quarantine them for 30 days first to ensure they don’t catch the disease). Vaccines are available to give your chickens, which should be administered about four weeks before outbreaks typically occur.

Keeping coops free from soil, spilled water, and feces is essential to preventing coryza. The bacteria thrive in atmospheres with little to no oxygen, so a damp, dirty coop can be the ideal place for the bacteria to grow and flourish.

Can Humans Get Coryza from Chickens?

No, coryza cannot be spread from chickens to humans. There is no public health risk if your flock has coryza, unlike other diseases, such as the bird flu, which only poses minimal risk to humans. However, you may want to warn neighboring farms if your flock has coryza, since it can be spread through air droplets. Just be sure to change out of any clothing you wore when you were around the infected birds before going over there.

A Healthy Flock Starts with Healthy Chicks

Keeping healthy chickens is essential to having a sustainable chicken operation. That’s why you need to be aware of the signs and symptoms of coryza in chickens. Not only can this disease decrease your egg production output, but it may also kill some of the birds in your flock. Keeping a clean and sanitized coop, practicing good biosecurity, and starting with healthy chicks or healthy eggs from Freedom Ranger Hatchery can help prevent this disease from infecting your farm.