Skip to main content

Common Chicken Illnesses and Diseases

A Guide to Common Chicken Illnesses and Diseases: What Every Backyard Chicken Keeper Should Know

Hey there, fellow backyard chicken enthusiasts! If you’re like me, you’ve fallen head over heels for these feathery friends, turning your backyard into a bustling coop full of clucks and cackles. Raising chickens can be incredibly rewarding, but it also comes with its fair share of challenges, especially when it comes to keeping them healthy. In this comprehensive 2500-word guide, I’m going to walk you through the common illnesses and diseases that can affect your backyard flock, so you can be better prepared to protect your feathered pals.

  1. Respiratory Infections

One of the most common issues that chickens face is respiratory infections. These infections can be caused by various pathogens like bacteria, viruses, and fungi. One prevalent respiratory disease is Infectious Bronchitis (IB). IB is highly contagious and spreads like wildfire through your flock. Symptoms include coughing, sneezing, nasal discharge, and a decrease in egg production. Unfortunately, there’s no cure for IB, so focus on prevention through vaccination and maintaining good coop hygiene.

  1. Egg Laying Problems

As backyard chicken keepers, we all eagerly await those fresh eggs each morning. But sometimes, our hens can face egg laying problems. One issue is egg binding, where an egg gets stuck in the hen’s oviduct. This can be painful and even life-threatening if not addressed promptly. Gentle massage and a warm bath can sometimes help, but it’s crucial to consult a vet if the problem persists.

Another common issue is soft-shelled or shell-less eggs. It’s typically caused by a lack of calcium in the hen’s diet. To prevent this, provide your chickens with a balanced layer feed and oyster shells as a calcium supplement.

  1. Parasitic Infestations

External and internal parasites can wreak havoc on your flock. Common external parasites include mites and lice. These little critters can make your chickens incredibly uncomfortable, leading to feather loss, itching, and irritability. Regularly inspect your chickens and coop for signs of infestations and treat with appropriate remedies like diatomaceous earth or poultry dust.

Internal parasites, such as worms, are equally concerning. They can cause weight loss, decreased egg production, and general lethargy. Regularly deworm your chickens and keep their living areas clean to prevent infestations.

  1. Coccidiosis

Coccidiosis is a prevalent intestinal disease caused by protozoa. It primarily affects young chickens. Symptoms include diarrhea, decreased appetite, and a hunched posture. Preventing coccidiosis is essential, as treatment can be challenging once an outbreak occurs. Use medicated feed for young chicks and maintain clean living conditions to minimize the risk.

  1. Marek’s Disease

Marek’s Disease is a viral illness that affects chickens worldwide. It’s highly contagious and can lead to paralysis and death. Early symptoms include unsteady gait and changes in eye color. Vaccination is the most effective way to protect your chickens from Marek’s Disease, so consult with your vet about an appropriate vaccination schedule.

  1. Avian Influenza (Bird Flu)

Avian influenza, also known as bird flu, is a viral infection that can be transmitted to humans. It can cause severe respiratory distress and high mortality rates among chickens. Prevention is crucial, so practice strict biosecurity measures, including limiting contact with wild birds, and report any suspicious symptoms to your local authorities.

  1. Fowl Pox

Fowl pox is a viral disease that can manifest in two forms: cutaneous (on the skin) and diphtheritic (in the throat). It causes wart-like lesions and can lead to respiratory distress if the diphtheritic form is contracted. Vaccination is available to protect your flock from this disease, but it’s essential to isolate infected birds to prevent further spread.

  1. Bumblefoot

Bumblefoot is a common condition in chickens that occurs when a bacterial infection enters a small cut or wound on the foot. It leads to swelling and the formation of a painful abscess. Prompt treatment includes cleaning the wound, antibiotics, and possibly surgery if the infection is severe. Regularly inspect your chickens’ feet and provide clean, dry bedding to reduce the risk.

  1. Newcastle Disease

Newcastle disease is a highly contagious viral illness that can affect multiple bird species, including chickens. Symptoms range from mild respiratory distress to severe neurological symptoms. Vaccination is the most effective prevention method, and it’s essential to quarantine and cull infected birds to prevent the disease from spreading.

  1. Sour Crop

Sour crop is a digestive disorder that occurs when food ferments in the crop, leading to a foul smell, regurgitation, and weight loss. To prevent sour crop, provide access to grit for digestion, maintain clean water sources, and avoid feeding chickens wet or moldy food. In mild cases, withholding food for 24 hours can help clear the crop, but severe cases may require veterinary intervention.


As backyard chicken keepers, our feathered friends rely on us to provide them with a safe and healthy environment. By being vigilant, practicing good biosecurity measures, and educating ourselves about common chicken illnesses and diseases, we can ensure the well-being of our beloved flock. Remember, prevention is often the best medicine, so invest in vaccinations, clean living conditions, and regular health checks to keep your chickens clucking happily in your backyard for years to come. Happy chicken keeping, everyone!