Chicken Health-What you need know about Chicken Diseases

Keeping My Chickens Healthy

Your backyard chickens can give you so much pleasure, becoming beloved family members, also giving you a constant supply of fresh, nutritious, delicious eggs. But like any other living things, they can get sick.

You need to know how to keep your chickens healthy. There are some common chicken diseases and conditions you need to be aware of, including symptoms to look out for, methods of preventing illness in your chickens, and basic ways to ensure your flock’s ongoing health and well being.

Common Chicken Diseases

Healthy Chicks

Like dogs and cats, backyard chickens may become unwell. This can be for an array of reasons, from poor diet to infections.

For backyard chickens, the most common causes of illness include:

External parasites

These are carried on the bird’s body. They may be larger (ticks) or microscopic (scaly face and leg mites); fleas and lice are also common. They can cause feather damage, itching and irritation, anemia, or tick fever. Backyard chickens should be checked and treated for external parasites regularly (two- or three-monthly).

Internal parasites

These include roundworms (visible to the naked eye in chicken poo) to microscopic organisms including Giardia, Trichomonas, and Coccidia. These parasites attack the intestinal lining and leach nutrients the bird needs for health and egg production. Signs include weight loss, diarrhea, and pale comb/wattle. Your birds need to be wormed every three months.


This viral disease affects older chickens in most cases, and also causes cancer. Tumors arise from the white blood cells and most commonly appear in the spleen or liver. Birds become listless and lose weight before eventually dying. This virus is transmitted via eggs. Euthanasia is the only real option for an infected bird.

Marek’s Disease

A virus that spreads between birds in dust and dander and is very easily spread by humans as well. Birds may not display signs of infection for months after exposure. The virus attacks the white blood cells, leading to cancer of the nervous system. Legs are most affected (paralysis) however neck and wings may be affected also. Tumors can cause weight loss, diarrhea, breathing difficulty, and failure to thrive. Most affected birds are quite young. Backyard chickens should be vaccinated against Marek’s Disease the day after they hatch.

Chicken Health

Fowl Pox

A virus spread by insects or fighting between birds. The virus is transmitted through a bite, scrape, or scratch. The resultant sores can sometimes be seen as a raised scab on the wattle or comb. most birds will recover and be immune for life, however secondary infections can be an issue. Vaccination is available.

Respiratory Disease

Sneezing, coughing, discharge from nostrils or eyes – all of these can be caused by dust, chemical exposure, parasites, viruses, or bacterial infection. Your vet needs to diagnose the exact cause to treat and prevent spread.

Reproductive Issues

Many commercial birds are not bred for longevity and are inclined to have problems reproducing. These include metritis (inflammation of the reproductive system), egg binding (eggs can’t pass from the bird), and yolk peritonitis (yolk is free in the abdomen, leading to infection). Surgery can resolve these issues but renders the bird unable to lay eggs.

Nutritional Deficiency In Chickens

Caused usually by a diet of table scraps alone. Low levels of calcium lead to rickets and poor bone growth; lack of carbohydrates leads to weight loss, low energy, and few eggs; lack of Vitamin A results in poor skin and feathering; lack of protein leads to poor growth, low egg production, and poor quality eggshells.

Exotic Diseases

These are poultry diseases which come from overseas. The most common of these seen in Australia are:

  1. Newcastle Disease – with almost 100% death rates, signs include mild respiratory symptoms, reduced egg production, severe depression, diarrhea, and collapse.

2.Avian Disease – symptoms appear suddenly, and death follows quickly. Symptoms include depression, diarrhea, swollen or

Symptoms of a Sick Chicken

If your chicken displays any of the following signs or symptoms, you need to have your vet come as soon as possible to check your birds:

  • Depression
  • Lethargy
  • Lack of appetite
  • Diarrhea
  • Breathing issues
  • Suddenly reduced egg production
  • Itching/skin irritation
  • Loss of weight
  • Something is just not right

Prevention of Chicken Disease

Healthy Chickens

Keeping your chickens healthy is the primary way of preventing disease.

  • Feeding – provide a diverse balanced diet of quality feed,grit, scratch,treats, and allow your birds to safely free-range. Keep feeders clean and store feed properly to ensure it remains dry and inaccessible to rodents.
  • Hygiene- bedding, clean coop – crucial for health and disease prevention, the coop, nesting boxes, and feeders need to be kept clean and fresh, with bedding changed weekly and the coop thoroughly deep cleaned once per month in summer and once every two months in winter (at least).
  • Water Supply – chickens need a constant supply of fresh water every day and preferably from a waterer they can not tip over or get into.


  • Limit the exposure of your flock to wild birds and waterfowl.
  • Worm your chickens regularly.
  • Check and treat your birds for external parasites

With appropriate love and care, your backyard chickens will be healthy and happy. Think of them like you would any other pet, and have them checked regularly by your poultry-friendly vet.