Common Chicken Illnesses and Treatments

Serious illness is unlikely in a backyard chicken flock, especially if you vaccinate the chickens. All the same, it’s good to be aware of illnesses in case you're ever wondering, is my chicken sick? Diseases can spread from wild birds and pests, so keep an eye out during your daily health checks for the symptoms listed below.

• Avian Pox/Fowl Pox:

  Symptoms: White spots on skin; combs turn into scabby sores; white membrane and ulcers in mouth, on trachea; egg laying stops; all ages affected.

  How contracted: Viral disease; mosquitoes, other chickens with pox, and contaminated surfaces.

  Treatment: Supportive care, warm dry quarters, soft food; many birds with good care will survive.

  Vaccine available: Yes; recovered birds are immune and do not carry the disease.

• Botulism:

  Symptoms: Tremors quickly progressing to paralysis of body, including breathing; feathers pull out easily; death in a few hours.

  How contracted: Caused by a bacterial by-product and by eating or drinking botulism-infected food or water.

  Treatment: Antitoxin available from vet, but expensive. If found early try 1 teaspoon Epsom salt dissolved in 1 ounce warm water dripped into crop several times a day.

  Vaccine available: None; locate and remove source, usually decaying carcass, carcass near water, or insects that fed on the carcass or the water the carcass is in.

• Fowl Cholera:

  Symptoms: Usually birds over 4 months — greenish yellow diarrhea; breathing difficulty; swollen joints; darkened head and wattles; often quick death. Does not infect humans.

  How contracted: Bacterial disease; wild birds, raccoons, opossums, rats, can carry. Also transmitted bird to bird and on contaminated soil, equipment, shoes, clothing contaminated water and food.

  Treatment: None — destroy all infected birds if recovery occurs the bird will be a carrier.

  Vaccine available: Yes, but only your state's agriculture department can administer it.

• Infectious Bronchitis:

  Symptoms: Coughing; sneezing; watery discharge from nose and eyes; hens stop laying.

  How contracted: Viral disease; highly contagious; spreads through air, contact, and contaminated surfaces.

  Treatment: Supportive care; 50 percent mortality in chicks under 6 weeks.

  Vaccine available: Yes. Give to hens before 15 weeks of age because vaccination will cause laying to stop.

• Infectious Coryza:

  Symptoms: Swollen heads, combs, and wattles; eyes swollen shut; sticky discharge from nose and eyes; moist area under wings; laying stops.

  How contracted: Bacterial disease; transmitted through carrier birds, contaminated surfaces, and drinking water.

  Treatment: Birds should be destroyed as they remain carriers for life.

  Vaccine available: None.

• Mareks Disease:

  Symptoms: Affects birds under 20 weeks primarily; causes tumors externally and internally; paralysis; iris of eye turns gray, doesn’t react to light.

  How contracted: Viral disease; very contagious; contracted by inhaling shed skin cells or feather dust from other infected birds.

  Treatment: None; high death rate and any survivors are carriers.

  Vaccine available: Yes, given to day old chicks.

• Moniliasis (Thrush):

  Symptoms: White tacky substance in crop; ruffled feathers; droopy looking; poor laying; white crusty vent area; inflamed vent area; increased appetite.

  How contracted: Fungal disease; contracted through moldy feed and water and surfaces contaminated by infected birds. Often occurs after antibiotic treatment for other reasons.

  Treatment: Yes. Ask a vet for Nystatin or other antifungal medication. Remove moldy feed and disinfect water containers.

  Vaccine available: No.

• Mycoplasmosis/CRD/Air Sac Disease:

  Symptoms: Mild form — weakness and poor laying. Acute form — breathing problems; coughing; sneezing; swollen infected joints; death.

  How contracted: Mycoplasma disease; contracted through other birds (wild birds carry it); can transmit through egg to chick from infected hen.

  Treatment: Antibiotics may save birds — see a vet.

  Vaccine available: Yes.

• Newcastle Disease:

  Symptoms: Wheezing; breathing difficulty; nasal discharge; cloudy eyes; laying stops; paralysis of legs, wings; twisted heads, necks.

  How contracted: Viral disease; highly contagious; contracted through infected chickens and wild birds and is also carried on shoes, clothes, and surfaces.

  Treatment: None. Birds under 6 months usually die; older birds can recover. Recovered birds are not carriers.

  Vaccine available: Yes, but the U.S. is working to eradicate the disease.

• Omphalitis (Mushy Chick):

  Symptoms: Newly hatched chicks — enlarged, bluish, inflamed naval area; bad smell; drowsy, weak chicks.

  How contracted: Bacterial infection of naval from unclean surfaces or chicks with weak immune systems. Can spread from chick to chick on contaminated surfaces.

  Treatment: Antibiotics and clean housing sometimes help, but most chicks will die. Remove healthy chicks immediately to clean quarters.

  Vaccine available: None. Use caution handling — staph and strep that cause this disease may infect humans.

• Pullorum:

  Symptoms: Chicks are inactive; may have white diarrhea with pasted rear ends; breathing difficulty; asymptomatic death possible. Older birds — coughing; sneezing; poor laying.

  How contracted: Viral disease; contracted through carrier birds and contaminated surfaces, clothing, and shoes.

  Treatment: Destroy all infected birds — birds that recover are carriers. Most chicks infected will die.

  Vaccine available: No vaccine, but there is a blood test to find carriers. While the U.S. is trying to eradicate this disease, buy chickens from Pullorum-negative flocks only.