Common Chicken Ailments O-Z

Here is a continuation of the common chicken ailments section. This selection is the diseases that are O-Z.

To Common Ailments A-C To Common Ailments D-N


Incidence: common chicken ailment

System/organ affected: navel

Symptoms: dead embryos late in incubation; newly hatched chicks feel wet. In chicks: drooping head, huddling near heat, lack of uniformity in size, lack of interest in food or water, mushy or scabby navel.

Cause: bacteria

Transmission: contaminated droppings on hatching eggs. high incubation humidity, infectious material in incubator, feed or water contaminated with droppings.

Prevention: hatch only eggs that have no cracks, and are clean. Control incubator humidity, clean and disinfect incubator.

Treatment: non effective.


Incidence: common chicken ailment

System/organ affected: bones

Symptoms: thickened leg bones, puffy looking shanks, lameness.

Cause: retrovirus

Transmission: contact with infected birds; spread by infected breeders through hatching eggs or from infected chicks to non-infected chicks through droppings, blood-sucking parasites.

Prevention: buying and breeding resistant strands.

Treatment: none; cull


Incidence: very common chicken ailment worldwide

System/organ affected: digestive or entire body

Symptoms: in embryos: numerous dead in shell at hatch. In chicks: death at time of hatch or depression, weakness, poor growth, drooping wings, increased appetite, increased thirst, huddling around heat with feathers ruffled.

Cause: Bacteria (salmonella)

Transmission: contaminated soil or litter (can persist for up to seven months), etc.

Prevention: difficult, due to the bacteria's wide range of animal hosts.

Treatment: none effective, survivors may be carriers. This disease must be reported to the federal public health administration.

Pasted Vent

Incidence: common in chicks, less common in mature birds.

System/organ affected: vent

Symptoms: in chicks: droopiness, droppings sticking to vent. In laying hens: offensive odor from droppings sticking to vent feathers.

Cause: unknown

Transmission: does not spread from bird to bird

Prevention: keep chicks warm and do not hatch eggs from affected hens.

Treatment: carefully pick away the matter stuck to the vent. Cull chicks that don't recover.

Pox (dry)

Incidence: common chicken ailment in some areas worldwide, especially in confined flocks in cold weather.

System/organ affected: skin

Symptoms: raised clear or whitish wart-like bumps on comb and wattles that grow larger, turn yellowish, and later become reddish brown, grey, or black bleeding scabs appearing as singles or in clusters.

Cause: pox virus that affects a wide variety of birds and survives for many months on scabs and feathers of infected birds.

Transmission: through skin wounds, feathers and scabs from infected birds. Also spread by mites, mosquitoes, and wild birds.

Prevention: control mites and mosquitoes and vaccinate where pox is prevalent.

Treatment: none; isolate infected birds in uncrowded housing. Remove scabs around mouth and eyes where birds can eat.

Pox (wet)

Incidence: worldwide but less common than dry pox.

System/organ affected: upper respiratory

Symptoms: white and scabby bumps on face, eyes, throat and windpipe.

Cause: same virus as dry pox invading the upper respiratory tract

Transmission: same as for dry pox

Prevention: same as for dry pox

Treatment: If thick discharge interferes with breathing, clear the bird's airway with Q-tip coated with iodine. Other than that, treat much like dry pox.

Rotaviral Enteritis

Incidence: common chicken ailment worldwide and increasingly more common

System/organ affected: digestive

Symptoms: in young birds: depression, diarrhea, inflamed vent, loss of appetite, weight loss.

Cause: rotavirus common in poultry houses, but it doesn't always cause disease.

Transmission: contact with infected birds and their droppings and spreads on contaminated equipment.

Prevention: clean and disinfect housing periodically and do not start new chickens on used litter.

Treatment: none; cull.

Chicken With Slipped Tendon

Slipped Tendon

Incidence: common in heavy, fast growing breeds

Symptoms: in young birds: swollen, flat hock joint, hopping on one leg, sometimes a leg twists and rotates to the side.

Cause: deficiency in manganese or one of five B vitamins.

Transmission: nutritional, does not spread from bird to bird.

Prevention: breed for genetic resistance, feed at least 95 percent commercial ration.

Treatment: manganese and vitamin B supplement won't reverse permanent damage, but will minimize future damage.


Incidence: common in free-range flocks in tropical and temperate climates, rare in North America.

Symptoms: droopiness, ruffled feathers, huddling, diarrhea with large amounts of white urates, uncoordinated, loss of interest in perching, lying with head on ground, convulsions, fever.

Cause: bacteria; it can infect many birds but does not survive very long in the environment.

Transmission: contact with moist droppings, blood, tissue or mucus from infected birds. Also can be spread by biting insects or ticks.

Prevention: control ticks and other blood-sucking insects. Do not house clean birds where an outbreak has occurred.

Treatment: none effective.

Staphylococcic Arthritis

Incidence: common chicken ailment worldwide

System/organ affected: joints or entire body

Symptoms: fever, reluctance to move, ruffled feathers, depression, swollen joints, resting on hocks.

Cause: bacteria

Transmission: bacteria entering body through wounds

Prevention: prevent injuries by providing safe, uncrowded housing.

Treatment: staph bacteria are resistant to many antibiotics, but treatment may be sufficient if a suitable antibiotic is determined by laboratory testing.

Sudden Death Syndrome

Incidence: common chicken ailment worldwide, especially in broilers.

System/organ affected: heart and lungs

Symptoms: in apparently healthy broilers, usually males, they get extended neck, gasping or squawking, wing beating, leg pumping, flipping onto back, and then death within one minute of first symptoms. In hens: cloacal tissue goes through vent and quick death.

Cause: unknown; may be caused by high carbohydrate feeds and rapid weight gain.

Transmission: nutritional, does not go from bird to bird.

Prevention: low-intensity lighting and avoiding noise and other disruptions.

Treatment: none


Incidence: common chicken ailment

System/organ affected: upper digestive tract

Symptoms: in growing birds: depression, rough feathers, diarrhea, slow growth and weight loss

Cause: yeast like fungus commonly living in bowels of chickens that infect when normal flora are disrupted by coccidiosis or antibiotics, growth promoters, and other drugs.

Transmission: contaminated droppings in drinking water

Prevention: good nutrition and sanitation and avoiding long term treatment with antibiotics and other drugs.

Treatment: isolate infected birds and clean and disinfect feeders and waterers.


Incidence: common chicken ailment worldwide, especially in backyard flocks in temperate Northern climates.

System/organ affected: starts in intestinal tract and migrates to other internal organs.

Symptoms: mature birds: dull, ruffled feathers, gradual weight loss, shrunken breast muscles, prominent keel, persistent diarrhea, decrease in laying.

Cause: bacteria

Transmission: droppings of infected birds or picking at contaminated carcasses of dead birds, spread by shoes and equipment.

Prevention: design housing so birds can't pick in droppings, do not mix birds.

Treatment: non effective.

Ulcerative Enteritis

Incidence: common chicken ailment worldwide

System/organ affected: lower intestine and ceca

Symptoms: in young birds: sudden death with no symptoms, hunched up posture with head pulled in and eyes closed, diarrhea.

Cause: bacteria that affect game birds more often than chickens. It persists under various conditions and resists disinfectants.

Transmission: contagious; spreads in droppings of infected carrier birds picked from litter, feed, and water.

Prevention: remove and replace litter between flocks or raise birds on wire. Avoid overcrowding and manage internal and external parasites.

Treatment: strepomycin in drinking water at rate of 15 grams per gallon for ten days. All survivors may be carriers.

To Common Ailments A-C To Common Ailments D-N

From Chicken Ailments to Chicken Diseases

New! Comments

Have your say about what you just read! Leave me a comment in the box below.
Share this page:
Enjoy this page? Please pay it forward. Here's how...

Would you prefer to share this page with others by linking to it?

  1. Click on the HTML link code below.
  2. Copy and paste it, adding a note of your own, into your blog, a Web page, forums, a blog comment, your Facebook account, or anywhere that someone would find this page valuable.


Custom Search