Chickens can be surprisingly difficult to assess when they are unwell. By the time a hen is obviously lethargic, has stopped eating or is sitting apart from the flock, the underlying problem may have been developing for some time.
This is partly because birds tend to conceal weakness. It is also because a chicken’s feathers can hide weight loss, swelling and changes in body condition that would be more obvious in a dog or cat.
For backyard chicken owners, the most useful skill is knowing what is normal for each bird. Appetite, activity, social behaviour, posture, droppings and egg production all give useful information. When one of these changes, particularly when several changes occur together, it is worth paying attention.
Many illnesses produce similar signs, so observation cannot replace a veterinary examination. It can, however, help owners recognise a problem earlier and provide useful information when a chicken does need veterinary care.
Changes in Behaviour Are Often the First Sign
A change in normal behaviour is one of the first things I encourage owners to notice.
A healthy chicken will usually spend a reasonable part of the day scratching, foraging, dust bathing, preening, eating, drinking and interacting with the flock. Individual personalities differ, so the important question is not whether one hen behaves exactly like another, but whether she has changed from her usual routine.
A chicken that suddenly spends more time standing quietly, hiding in the coop, remaining on the perch, or separating from the other birds should be watched carefully.
Social position can change as well. A bird that previously held her own in the flock may start being pushed away from food or picked on by other chickens. As discussed in our article on chickens and behaviour, illness and flock dynamics are closely connected. Other chickens may respond to a bird that is weaker or behaving differently before the owner has noticed an obvious physical problem.
Not every quiet chicken is sick. Broodiness, moulting, hot weather and changes within the flock can all affect behaviour. It is the combination of signs and the departure from that particular bird’s normal behaviour that matters.
Watch Appetite and Water Intake
Changes in eating and drinking deserve attention, even when the chicken has not stopped eating completely.
An unwell hen may still approach food but eat less, take longer to eat, pick selectively at favourite foods, or leave the feeder sooner than usual. In a group setting this can be difficult to notice, particularly if food is always available.
This is one reason it helps to spend a few minutes actually watching the flock eat rather than simply checking whether there is food left in the feeder.
Water intake can also change. Drinking more than usual can occur with hot weather and some dietary changes, but it can also accompany disease. Drinking less may occur when a chicken is weak or unwell and can quickly lead to dehydration.
If you are concerned about one bird, observing her separately for a short period can make it easier to see how much she is actually eating and drinking.
Weight Loss Can Be Hidden by Feathers
A chicken can lose a considerable amount of body condition without looking dramatically thinner. Feathers give the body a rounded appearance, so visual assessment alone is unreliable.
When handling your chickens, become familiar with the muscle on either side of the keel, or breastbone. In a well-conditioned bird, there should be reasonable muscle covering on both sides. If the keel becomes increasingly prominent and the breast muscles feel reduced, the bird may be losing condition.
Periodic weighing can also be useful, particularly for older birds or chickens with a history of illness. A consistent downward trend is more informative than trying to decide whether a fully feathered hen simply “looks a bit thin”.
Unexplained weight loss may occur with parasites, chronic infection, reproductive disease, poor nutrition and many other conditions. It is a sign to investigate rather than a diagnosis in itself.
Look at the Comb and Wattles
The comb and wattles can provide useful clues, although their normal appearance varies with breed, age, reproductive status and weather.
A laying hen will often have a reasonably full, well-coloured comb. A very pale comb can occur with anaemia, blood loss, parasites or chronic disease, although some normal physiological changes can also alter comb colour.
A comb that becomes markedly shrunken, unusually dark, bluish or swollen also deserves attention, particularly if the bird is lethargic, breathing abnormally or showing other signs of illness.
Colour alone should not be used to diagnose a chicken. It is one piece of information to consider alongside appetite, activity, weight, breathing, droppings and egg production.
Posture Can Tell You a Lot
Owners who know their chickens well will often notice that an unwell bird simply “looks wrong”.
A sick chicken may stand hunched with feathers fluffed out, hold her wings differently, close her eyes frequently, tuck her head in, or remain stationary while the rest of the flock is active.
Lameness may be obvious, but sometimes the change is much smaller. A chicken may put less weight on one foot, hesitate before jumping onto a perch, sit more often, or stop scratching normally.
Check the feet for swelling, wounds and abnormal areas on the pads, but remember that leg weakness or an altered gait does not always originate in the foot. Joint disease, injury, neurological problems, nutritional disease and other conditions can affect movement.
A chicken that cannot stand normally, repeatedly falls over or develops an abnormal head or neck position needs prompt veterinary attention.
Weakness or Paralysis Needs Prompt Investigation
Weakness, an abnormal gait or paralysis should never be assumed to be a simple leg injury. One important disease to consider in chickens is Marek’s disease.
Marek’s disease is caused by a herpesvirus and is highly contagious. Birds are often exposed when they are young, but signs may not develop until weeks or months later. The virus affects nerves and can also cause tumours in internal organs.
Signs can include weakness or paralysis of one or both legs, drooping wings, difficulty standing, weight loss, changes to the iris or pupil, and impaired vision. Affected birds may initially look as though they have injured a leg because neurological signs can develop before other problems are obvious.
There is no effective treatment for a chicken that develops clinical Marek’s disease. Vaccination is the main method of prevention and is most effective when given to chicks at or soon after hatching, before they are exposed to the virus.
Not every chicken with leg weakness or paralysis has Marek’s disease. Injury, nutritional problems, reproductive disease, toxins and other neurological conditions can produce similar signs, so veterinary assessment is important.
Pay Attention to Breathing
Normal breathing in a resting chicken should generally be quiet and relatively effortless.
Coughing, sneezing, nasal discharge, watery eyes, facial swelling, open-mouth breathing or obvious effort with each breath can indicate a respiratory problem. Changes in voice may also occur.
Panting requires some context. Chickens pant during hot weather to lose heat, and they may hold their wings away from their body at the same time. A chicken that is panting when the weather is not hot, however, or continues to breathe heavily after being moved to a cooler environment, needs closer assessment.
Breathing problems should not be left for several days to see what happens. Birds have a specialised respiratory system and can deteriorate quickly when respiratory disease is significant.
Droppings Are Useful, but Don’t Diagnose From One Dropping
Chicken droppings naturally vary during the day. Caecal droppings, for example, are softer, darker and smellier than ordinary faeces and can alarm owners who have not seen them before.
Diet, water intake and hot weather can also alter the appearance of droppings.
What is more concerning is a persistent change from normal, particularly when it occurs together with reduced appetite, weight loss or lethargy. Repeated watery droppings, blood, large amounts of mucus, unusual colour, undigested food or significant soiling around the vent warrant closer attention.
Parasites and intestinal disease are among the possible causes, but similar changes can occur with other health problems. Treating every abnormal dropping with an over-the-counter wormer is not a good approach.
Diagnosis matters. Different parasites and diseases require different treatment, and unnecessary medication can create its own problems.
Check the Crop When Something Seems Wrong
The crop is a temporary food-storage pouch and its size naturally changes during the day. It may feel quite full after a chicken has been eating and should normally reduce as food passes through the digestive system.
Problems become more likely when the crop remains persistently enlarged, feels abnormally hard or fluid-filled, or is still markedly full before the bird has eaten in the morning.
A chicken with a crop problem may also lose weight, eat less, appear uncomfortable or develop an unpleasant smell from the mouth.
Crop problems have several possible causes and should not automatically be treated as a simple blockage. If the crop is not emptying normally, veterinary assessment is preferable to attempting home treatments based on an online diagnosis.
Check for Parasites, but Don’t Assume Every Scratch Means Mites
Backyard chickens are exposed to an environment where internal and external parasites can occur.
Lice and mites may cause irritation, feather damage, restlessness and reduced condition. Heavy infestations can contribute to anaemia and weakness. Red mites can be particularly easy to miss because they may spend much of the daytime hiding in cracks and crevices of the coop rather than sitting visibly on the bird.
Internal parasites may contribute to weight loss, poor condition, diarrhoea or reduced egg production.
However, scratching and preening are also normal chicken behaviours. Parasite treatments should not simply be used because a bird scratches occasionally. If parasites are suspected, identifying what is actually present allows the correct treatment to be chosen.
Changes in Egg Laying Need Context
A reduction in egg production does not automatically mean a hen is sick. Age, breed, season, daylight hours, moulting, broodiness, heat and stress all influence laying.
A sudden unexplained change can still be important, especially when accompanied by other signs.
Changes in shell quality, unusually shaped eggs, repeated soft-shelled eggs or a marked change in egg size can sometimes provide useful information about nutrition, stress, reproductive health or general condition. We have covered these changes in more detail in Egg Health and Nutrition: What Your Chickens’ Eggs Say About Their Wellbeing.
Reproductive disease is relatively common in laying hens. Warning signs can include repeated straining, spending an unusual amount of time in the nest without producing an egg, a swollen abdomen, an abnormal upright or “penguin” stance, reduced appetite, lethargy or difficulty breathing.
These signs need veterinary attention rather than repeated attempts to manage the problem at home.
Don’t Ignore Abdominal Swelling
An enlarged abdomen can be easy to miss in a feathered bird until it becomes quite pronounced.
Reproductive problems are one possible cause, particularly in mature laying hens, but there are other possibilities. A swollen abdomen may also change the way a chicken walks or breathes.
If a hen develops obvious abdominal enlargement, begins walking differently, stops laying unexpectedly or appears uncomfortable, she should be examined.
Our broader guide to keeping chickens as pets also discusses reproductive disease and some of the other health problems seen in backyard hens.
Look at the Whole Chicken, Not One Symptom
One abnormal sign rarely tells us exactly what is wrong.
A pale comb does not automatically mean worms. Loose droppings do not automatically mean infection. A hen that stops laying is not necessarily egg bound. A chicken sitting away from the flock is not necessarily being bullied.
The useful information comes from putting the signs together.
For example, a hen that has become quiet, lost weight, developed a pale comb and reduced her egg production needs a different level of concern from an otherwise bright hen that has simply stopped laying during a moult.
This is also why a veterinary examination is useful. Chickens can develop respiratory and reproductive disease, parasites, nutritional problems, infections, neurological disease, injuries and tumours with considerable overlap in the signs owners see at home.
When Several Chickens Become Sick at Once
One sick hen and several birds becoming ill over a short period are different situations.
If several chickens suddenly become lethargic, stop eating or drinking, develop respiratory signs, show neurological abnormalities, or if there is an unexplained increase in deaths or a sharp drop in egg production, seek veterinary advice promptly.
Some serious poultry diseases, including avian influenza and virulent Newcastle disease, are nationally notifiable in Australia. Owners should not attempt to move sick birds to another property or introduce new birds while an unusual flock-wide illness is being investigated.
Suspected emergency animal disease can also be reported through the national Emergency Animal Disease Hotline on 1800 675 888.
For the average backyard owner, there is no need to try to distinguish these diseases at home. The important thing is recognising when illness is affecting the flock rather than one individual chicken and obtaining advice early.
What to Do When You Notice a Sick Chicken
When one chicken appears unwell, observe the rest of the flock as well. Check whether other birds are showing similar changes and look at food intake, water consumption, droppings and egg production.
A sick bird may need to be separated from the flock to prevent bullying and allow closer monitoring. Separation is also important when infectious disease is possible. Keep her somewhere secure, quiet and protected from weather extremes while veterinary advice is sought.
If possible, make a note of when the change started and any recent events such as introducing new birds, changing feed, extreme weather, predator disturbance or changes in laying. Photos of droppings, the coop or any visible abnormality can also be useful.
Avoid starting several medications at once. Antibiotics, wormers and parasite treatments will not help every problem and may make diagnosis more difficult.
Regular Observation Is the Best Early Warning System
You do not need to examine every chicken from head to toe every day. What helps most is knowing how your flock normally behaves.
Notice which birds come running for food, where they perch, how they walk, what their normal comb colour looks like and how they interact with one another. Pick birds up periodically so you know what their normal body condition feels like.
Changes become much easier to recognise when you have that baseline.
This same principle applies across bird and exotic animal medicine. Our article on regular health checks for exotic pets explains why establishing normal weight, body condition, behaviour and husbandry can make early illness easier to identify.
For backyard chickens, early veterinary assessment is particularly useful because so many different problems initially look alike. Rather than treating a symptom in isolation, we look at the whole bird: diet, body condition, reproductive history, parasites, housing, flock behaviour and any physical signs found on examination.
Knowing your chickens well, and acting when something changes, remains one of the simplest ways to detect health problems before they become more serious.
