Telling Poultry Respiratory Diseases Apart

Sneezing is a symptom, and four diseases share it

Three birds sneezing in the corner of a house are not yet a diagnosis. They are a clue, and the clue points at four very different problems that look alike from the path. Newcastle disease, infectious bronchitis, chronic respiratory disease and infectious coryza can all make birds gasp, cough, shake their heads and go off their feed. Treating them the same way is one of the most expensive mistakes a farmer can make, because two of them must be reported the moment you suspect them.

This guide compares those four side by side. It is written for the first 24 to 48 hours, when you are deciding whether to call the vet today, how to separate the birds, and what to watch. It does not replace a diagnosis. Only a vet, using a post-mortem and laboratory tests, can confirm which disease is in your house, and sometimes two diseases are present at once.

The useful habit is to stop asking "what is wrong with my birds?" and start asking three smaller questions. How old are the affected birds? How fast is the problem spreading? What else changed, such as eggs, droppings or nervous behaviour? The answers narrow the list far more than the sneezing does.

The four suspects, side by side

The table below is a comparison, not a checklist to diagnose by. Use it to see where your flock fits, then take the notes to your vet.

Two rows matter most at the start. The speed row tells you whether you are looking at something in hours or in weeks. The nervous-signs row tells you whether you have to call the vet at once.

Newcastle disease: the one you cannot ignore

Newcastle disease is the reason every farmer should know this table by heart. It is caused by a paramyxovirus, and the strains that matter for field disease are the severe ones, called velogenic. Severe strains cause sudden death, high losses and obvious nervous signs. Milder strains are used in some vaccines, and vaccinated birds may show a milder version of the disease if the virus does reach them.

In a flock with unvaccinated birds, the early picture is often a bird that is simply off its feed, then several birds breathing with a rattle, then deaths within a day or two. Some birds show a green, watery diarrhoea. Nervous signs such as a twisted neck, tremors, or legs and wings that will not work are classic. Laying hens may drop their output sharply, and the eggs that do come can be soft-shelled or misshapen.

Vaccination changes the picture. A vaccinated flock may cough, sneeze and lay fewer eggs without the mass deaths of an unvaccinated flock. That is harder to spot, because the signs look like a mild cold. This is why a sudden drop in eggs or a rise in quiet deaths must be checked, even in a flock that has had its vaccines.

The rule is simple. If you suspect Newcastle disease, isolate the affected birds where you can, stop the movement of birds, eggs and equipment, and call your district veterinary office or the Veterinary Services Directorate at once. Do not wait to see whether it passes. Our guide on Newcastle disease prevention explains the vaccination side, and the reporting duty is explained on our outbreak steps page.

Infectious bronchitis: fast through the house, gentle on the count

Infectious bronchitis is a coronavirus, and it is the disease that tends to surprise farmers with how quickly it crosses a shed. In a house of chicks, you may see sneezing and watery eyes in one corner on Monday, and most of the birds showing signs by Wednesday. The mortality is often modest, which is exactly why IB gets underestimated.

The exception is the kidney-damaging strains, sometimes called nephropathogenic. These can cause real deaths, and they show a different picture: birds that look hunched, drink more, and produce watery droppings with white urate deposits. A post-mortem vet will often find swollen kidneys and urate in the tubules. This form can look like a kidney or water problem at first, so do not assume it is simply a feed issue when the birds are also breathing badly.

In laying flocks, IB shows up as a sharp and sometimes lasting egg drop. The eggs can have rough or thin shells, misshapen outlines and watery whites. Some farmers notice that their hens stop laying and then restart weeks later, which is one reason the drop is easy to blame on feed or heat. Count the eggs each day. A sudden fall that matches a cough in the house deserves a vet visit.

Because IB has many variants, vaccination is about matching the strain as well as giving the dose. Our infectious bronchitis guide covers the vaccine and house points, and the wider reasons vaccines miss are in our piece on why vaccines fail.

Chronic respiratory disease: the cough that never quite leaves

Chronic respiratory disease is the slow one. It is caused mainly by Mycoplasma gallisepticum, which is a very small bacterium without a proper cell wall, so it behaves differently from most bacteria. It can spread through the egg, which means a flock can start life carrying it. It then spreads through the house by close contact, and its effects are amplified by other infections.

The signs are a cough that comes and goes, nasal discharge, a rattling sound when the birds breathe, and sneezing. Growth slows, and birds that should be filling out look thin and listless. In a laying house, egg output falls gradually rather than all at once. The mortality is usually low to moderate, which makes CRD seem like a nuisance. Its real cost is in weight, feed and months of poor production.

The trouble is that CRD rarely travels alone. E. coli infects the damaged airways and air sacs, and the post-mortem often shows cloudy or cheesy material in the air sacs. That is why many CRD outbreaks are described as CRD complicated by E. coli. The stressor that tips a mild flock into a visible outbreak is usually something you can name: a move, a cold snap, a poor feed change, crowding or ammonia from wet litter.

Treatment of CRD is a vet decision, because the choice of medicine depends on the bacteria and the flock. Do not start a course of medicine on the strength of a cough. Use the hatchery and house checks in this guide first, and then discuss a plan with your vet. For more on why this matters, read our note on responsible antibiotic use in poultry.

Infectious coryza: the swollen face and the foul smell

Coryza is the one that often shows itself in the face. The sinuses under the eye swell, sometimes so much that the bird looks as if it has a lopsided face. There is a nasal discharge that smells quite distinctive, and the eyes water. Birds stop eating well, and in layers the egg count falls. The mortality is usually low, which is why many farmers treat it as a cold and wait. The problem is that the infection can linger in the flock and flare again.

The bacteria spread through water and close contact. Drinkers that are shared, birds that are moved between houses, and mixed-age flocks where young and old birds share space all make coryza more likely. Cold draughts, dusty air and ammonia increase the damage to the airways, which is why it often appears in the harmattan months or in a poorly ventilated house in the rains.

Because coryza responds to some antibiotics and not others, the vet will usually want a sample sent for culture so that the right medicine is chosen. This is where a clear note matters. Record how many birds show the swollen face, whether the eyes are involved, when the drop in eggs began and whether new birds came into the house in the last month.

Our page on coryza, or swollen head covers the signs in more depth. Coryza and CRD are the two respiratory problems most often mistaken for each other, so if your birds show both swelling and a long cough, make sure the vet looks at both possibilities.

Narrowing the list with age, speed and eggs

Before you call the vet, write three lines in your book. These three lines do most of the sorting work.

1. Age. Which birds are affected, and how old are they? Chicks in their first weeks point toward IB and a range of other causes. Adult layers with a sudden egg drop point toward NCD, IB or a bacterial problem. Older birds with a slow cough often point toward CRD.
2. Speed. How long from the first sneeze to the tenth bird? Hours or a day or two suggests NCD or IB. Weeks suggests CRD. A few birds at a time, with a swollen face, suggests coryza.
3. Eggs and nerves. Has egg output changed, and are the eggs soft, misshapen or thin? Is any bird twisting its neck, tremoring or unable to stand? Nervous signs and a sudden egg drop together call for the vet the same day.

Then count. Walk the house at the same time each morning and count the birds showing each sign, then count again that evening. A number that rises over three or four days is a warning. A number that stays flat and low may be a flock that is coping. Write the figures down, because your vet will ask for them.

Finally, check what has changed in the last ten days. A new batch of birds, a visitor from another farm, a change in feed, a cold night, a drinker that was not cleaned, or a new litter material can all be the trigger. Those changes often explain the timing better than any laboratory result.

What a vet looks for in a post-mortem

A good post-mortem is one of the most useful tools in the poultry business, and it does not need a lab to start. Your vet will open several birds and look at the same organs in each, because the pattern across birds matters more than one bird alone. The main places to look are the windpipe and its contents, the air sacs, the sinuses, the kidneys and the digestive tract.

A vet who sees a few birds opened on the same day, and who knows the age and history, can often narrow the list quickly. That is why it pays to bring a few fresh dead birds rather than one bird that has been left in the sun for two days. Keep the carcasses cool, not frozen, and do not dissect them yourself unless the vet asks you to.

Why harmattan dust and wet litter make every disease worse

In Ghana, the harmattan arrives in December and January with dry, dusty air and cold nights. In Kasoa, December is also when festive demand for birds peaks, and for many farmers it is the month when sneezing starts in the house. The dust itself irritates the airways, and it carries bacteria and fungal spores into the lungs of birds that are already stressed.

Wet litter is the opposite problem and is just as serious. When droppings and urine stay in damp bedding, ammonia rises. Ammonia at even moderate levels damages the lining of the windpipe and the air sacs, and that damage gives the respiratory bacteria a way in. Smell the house in the morning. If you can smell ammonia when you walk in, the birds can smell it too, and their breathing will show it.

The fix is ventilation without draughts. Open the sides high rather than low, keep the sides and roof sound, and avoid blowing cold air directly onto the birds at night. Keep the litter dry and turned, and replace the wettest patches before they become a problem. Our notes on brooding through the harmattan and on climate-smart poultry housing set out the house changes in more detail.

What to do this week, step by step

When you suspect a respiratory problem, these are the steps we would expect a careful farmer to take. They do not replace your vet's advice, but they make the vet's visit far more useful.

1. Call your district veterinary office or your private vet the same day, and describe the age, speed, eggs and nervous signs.
2. Count the affected birds morning and evening, and write the numbers down.
3. Separate any birds that are very sick and keep them warm, dry and near feed and water.
4. Stop moving birds, eggs, crates and visitors between houses until the vet has seen the flock.
5. Clean the drinkers, and check the litter for dampness and ammonia.
6. Check the feed for dust, mould and any recent change.
7. Keep dead birds cool and ready for the vet, and do not throw them into a pit without asking first.
8. Do not start antibiotics or other medicines without a diagnosis, unless the vet tells you to.

If the flock is young and you bought the chicks from us, send us the batch number and a short message on WhatsApp at +233 24 915 1503. We keep vaccination records for each batch, and those records help your vet know what protection the birds started with.

Samples and what your vet will ask for

Laboratory confirmation is the difference between a good guess and a proper answer. The usual samples for suspected NCD or avian influenza are swabs from the throat and the vent of live birds that show signs, together with several fresh dead birds that are as recent as possible. Samples must be kept cool and sent to the right laboratory, under the vet's instructions. Your vet will know the current sample and transport rules.

For CRD, coryza and IB, the vet may take samples for culture, serology or PCR, depending on the disease and the questions being asked. Serology tests look for antibodies and can show whether birds have met a disease, while PCR looks for the genetic material of the organism. Neither test is perfect on its own, which is why a good vet looks at the whole history.

Bring the following to the visit, because nearly every vet asks for them:

• The age, breed and number of birds in the affected house.
• Vaccination dates and the batch record for the flock.
• Your daily count of birds with signs, and any deaths.
• Egg records for layers, including the day the drop started.
• Recent changes in feed, water, litter, visitors or stock.

Keeping the next flock clear of these four

Most respiratory trouble is preventable, or at least easier to manage, when the basics are right. Vaccination is the first line for NCD and IB, and the vaccine must match the strain circulating in your area. Ask your vet which products to use and when. Our hatchery vaccinates chicks for Newcastle and infectious bronchitis before they leave us, and the batch record shows the dates, but your vet will still need to plan the follow-up doses.

For CRD and coryza, the prevention is mostly management. Buy from sources that keep their breeding stock clean, keep flocks of different ages apart, use a clean-in, clean-out routine between batches, and restrict visitors. Our biosecurity guide sets out the routine step by step. Ask your vet whether a control programme for Mycoplasma suits your flock, because the answer depends on your breeding and history.

Ventilation, dry litter and steady feed do more to protect the airways than any single product. A flock that is not stressed by cold draughts, dust or ammonia is much harder for a respiratory bug to tip over. If you are planning a new house, plan the ventilation first and the stocking density second, not the other way round.

If you want to start a new flock with birds that come with a documented vaccination history, you can order through our order form, or see our day-old chicks and layer chicks pages for what we currently supply. Questions about the batch record can go to our FAQ.

Questions farmers ask