Infectious Coryza in Chickens. All You Need to Know!

Infectious Coryza in Chickens. All You Need to Know!

Jun 05, 2024angelique van zuylen

Coryza is essentially a nasty cold in chickens. Doesn’t sound too serious does it? 

Unfortunately it is. 

Coryza is a highly contagious🦠 bacterial infection in chickens that spreads fast and is impossible for your flock to truly recover from. 

It’s potentially fatal for weaker and older birds and can find distraught chicken keepers forced to cull their entire flocks. 

Before I totally freak you out – it is preventable - so stay put and we will cover how to spot the signs, how to treat it and how to prevent it in the first place.

Infectious Coryza causes extreme cold-like symptoms: inflammation of the face and wattles, snotty nostrils, gunky eyes, sneezing, breathing problems, reduced appetite, weight loss, and hindered egg production. It’s horrible. We’ve all been there!

What Is Coryza?

Coryza is essentially a cold in chickens caused by the bacteria, Avibacterium paragallinarum. It’s a cattarhal infection of the upper respiratory tract which means that the bacteria cause inflammation of the mucus membranes, enlarged blood vessels, swollen tissues, and discharge.

Whilst it’s not quite as catastrophic for your coop as something like Marek’s disease, it’s much worse than a human cold, causes poor growth in young chickens, a 10-40% reduction in egg laying and fatalities in older or weaker birds. 

Even when chickens recover from coryza they always carry the pathogen and can never be introduced easily to new birds, require lifelong treatment and are likely to relapse.

Coryza symptoms

Coryza in chickens looks like the common cold in every way. 

The swelling of the sinus causes discharge from their eyes and nose known as lacrimation. This is basically a snotty beak and conjunctivitis. They’ll have very teary, gunky eyes which will eventually close completely.

The discharge from your chicken’s nose will be watery to begin with and then start to stink as their sinuses become infected with puss. Yuck.🤮 

Blocked sinuses make it hard for your friend to breathe and in turn they’ll sneeze and cough frequently which is why it spreads so fast.

Infected roosters - who of course have man-Coryza - may also show signs of inflamed wattles. 

Coryza Symptoms include:

  • Nose and eye discharge with a pungent smell
  • Sneezing & coughing
  • Swelling of the face, wattles, and eyes
  • Difficulty breathing – open mouth
  • Reduction in egg production
  • Loss of appetite
  • Weight loss
  • Lethargy and difficulty walking
Swollen head syndrome (less common)

How Is Coryza Spread?

Coryza is airborne and passes directly from chicken to chicken by infected droplets of saliva, snot, or any other yuckies they cough up. Poor things. The bacteria can then be ingested or inhaled through contaminated feed, water, bedding or dust particles. 

How Fast Does Coryza Spread in Chickens?

The incubation period for Coryza is just 1-3 days. You probably won’t spot any symptoms during these first few days which is why you need to act fast when your chickens are symptomatic during the following 48 hours. Sadly Coryza is always likely to have spread to the whole flock by the time you’ve spotted the signs and all your birds are likely to be full of cold within ten days.

Does My Chicken Have Coryza?

If your chicken is showing any of the coryza symptoms listed above then they’re unwell in one way or another so you’ll need to seek the support of your vet to diagnose what your chicken is suffering from.

What To Do If You Suspect Coryza

1. Isolate Your Sick Chick

You might think isolating your sick chick is pointless if all your other chickens are likely to be sick soon too but it’s not. The first chickens to show symptoms will be weak and can be pecked at by other chickens so in the case of coryza isolation is to protect the sick chicken rather than your asymptomatic flock.

2. Treat The Entire Flock

The first thing to do is call your vet who will test your chicken and prescribe the right antibiotic. You’ll need to declare your entire flock to get the right quantity of medication and guidance on how to treat every bird.

“If you cannot get your chicken to the vet immediately, be sure to isolate her from the rest of the flock until you can. Keep her in a warm, dry place and give her food, water and a little apple cider vinegar.” (Source Chickenpedia)

3. Tell Your Neighbors 

This can feel like the walk of shame as you shuffle up the sidewalk ready to ruin your neighbor’s day but it’s really important to spread the word so that you can stem the spread. They’ll want to treat their chickens too.

4. Avoid Cross-Contamination

If you are in contact with a friends flock then you’ll need to postpone those coffee visits for a while! The bacteria can be carried on your shoes or clothing so even washing your hands thoroughly isn’t cautious enough if you want to avoid any further heartache.

Can People Catch Coryza?

In humans coryza is the cause of the common cold. It’s highly contagious, very common and there are lots of strains out there and whilst it’s horrid to have it’s not dangerous. In chickens however coryza can be fatal. 

Can I Catch Coryza from my Chicken?

You can’t catch your chicken’s cold. These pesky poultry pathogens are not zoonotic: they don’t spread from one species to another. The common cold strain that’s affecting your chickens is not the same one that you suffer miserably with a couple of times a year. You’re all good! 

Can I Eat My Chicken’s Eggs if They Have Coryza?

The eggs🥚 of a positive coryza bird are still safe to eat just as long as they’re not currently on any antibiotics. You can even eat the meat of a chicken carrying coryza since the chicken strain of coryza is not harmful to humans. 

Preventing Coryza in Chickens 

You can minimize the risk of your cute little coop troop catching this deadly cold with these easy, affordable methods of prevention.

1. Practice Good Housekeeping

Coryza can be killed by heat, drying, and disinfectants. A thorough deep clean of your coop twice a year and regular cleaning of feeders and waterers will reduce the risk of a fatal coryza infection.

2. Pay Attention to Biosecurity

Safeguarding your chickens from other animals, pathogens, and the general transfer of bacteria. Don’t walk from flock to flock without cleaning or changing your shoes and washing your hands as a minimal.

3. Manage Introductions of New Birds

Quarantine any new birds for a few weeks to make sure they don’t become symptomatic of coryza before introducing them to your flock and minimize contact with wild birds as best you can

Treating Coryza in Chickens

Coryza can be treated and symptoms can be managed but the infection can never be eradicated.

We would always say get straight to the vets but if it’s not possible some keepers treat early coryza symptoms with colloidal silver. It’s known to be antibacterial and can be syringe fed. 

Get your sick chook to the vet as soon as you can – I know you’ll be desperate to get them the help they need – and using the wrong over-the-counter antibiotics can inadvertently make things even worse for them.

Your vet will treat your sickly chick with the right antibiotics administered by injection making them more powerful and more easily absorbed into the bloodstream. 

You’ll need to treat the rest of your flock since they’re likely all carriers of coryza. Treating them early on will help them fight the bully-boy bug before it gets any worse. 

There are other home remedies like grapeseed extract, apple cider vinegar, and garlic which can help ease the symptoms and make your chickens recovery less upsetting. Natural herbs like oregano, thyme, and grapefruit seed extract contain antioxidants and vitamins known to boost your immune system. Shop our Coryza Homeopathic Blend.

Can Chickens Recover from Coryza?

20% of infected chickens won’t survive Coryza. In older birds or weaker flocks the mortality rate could be as high as 50%.

Chickens can recover but will always carry the bacteria. This means that if you introduce a new chicken to your seemingly healthy flock it’s likely they’ll come down with this killer cold too.

Do I Need to Cull My Chickens with Coryza?

The heart-breaking fact about this evil illness is that you can treat and nurse your chickens to recovery but you can never reverse the infection. 

Recovered chickens will always carry the pathogen meaning new chooks can’t be introduced to your coop and excessive care will always be called for when traveling from flock to flock. 

If you keep your chickens free-range and your neighbors have chickens the risk to all neighboring flocks will never go away either.

The reality of the long-term impacts of coryza infections can force people into the soul-destroying decision to end the lives of all of their chickens even after recovery. As the bacteria can live in the soil for years you’ll need to wait at least six months before introducing new chickens to your home again. 

Could My Chicken Get Coryza?

All chickens are sadly at risk of contracting Coryza but some environmental and physiological factors that might increase the risk of infection for your chickens:

1. Location

Infectious Coryza is on the rise in the US. It’s common pretty much everywhere. 

2. Environment

Being an anaerobic bacillus (fancy chat for doesn’t need oxygen) it thrives in moist environments with little to no oxygen. Soil, water and poop are perfect! Soil, water and poop in a warm, damp and dirty coop are even better. Keeping your chicken mansion clean, dry and well ventilated will dramatically reduce the spread of bacteria. Shop our Coop Cleaner.

3. Previous Coryza Infection

Once a chicken has had Coryza even if they recover symptomatically they’ll always be a carrier. This means that they are susceptible to regressions if they are stressed or otherwise unwell. 

4. Stress

Stressed chickens are more prone to illness in general including coryza. Changes to their environment or new chickens in the flock can result in a lowered immune system.

5. Show Birds

Poultry shows are the riskiest places to take your chickens. Whilst it’s a great place to enjoy thousands of gorgeous chickens brought together to strut their sexy stuff the bacteria and pathogens of planet poultry are strutting their stuff too…all over the place!

6. Cross-contamination

If you travel from flock to flock with work or caring for neighbor's birds etc, the risk of cross-contamination is higher.

7. General Health, Nutrition, & Wellbeing

A well-fed and nourished chicken will be stronger in every way and so able to fight off any illness faster and more efficiently than weaker or older birds. This is egg-sactly why mastering your chicken’s menu is so important! 

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