Causes of Lameness in Poultry

Small and Backyard Flocks May 24, 2013 Print Friendly and PDF

There are multiple diseases and conditions that can cause lameness in poultry.

Viral Infections

Viral Arthritis

Lameness with swollen hocks is one clinical signs of viral arthritis.

Marek's Disease

Marek's disease affects chickens. Clinical signs of this disease include the following:

  • Unilateral paralysis of the wing or leg
  • Lameness
  • Unthriftiness 
  • Gray eyes and blindness

Bacterial Infections


Staphylococcus infection is also known as bumblefoot. Clinical signs of this disease include the following:

  • Lameness
  • Swollen joints and foot pads


Clinical signs of pasteurella infection include the following:

  • Darkened head 
  • Swelling of the head and wattles 
  • Paralysis
  • Reduced egg production
  • Retarded growth

Nutritional Conditions

Nutritional deficits can lead to diseases that cause lameness.


Clinical signs of rickets include the following:

  • Lameness
  • Softness of the bones and beak
  • Reduced egg production or production of thin-shelled eggs

Cage Layer Fatigue

Birds with cage layer fatigue are alert but paralyzed and can die from dehydration.

Mycoplasmal Infections

Mycoplasmas are bacteria that lack a cell wall.

Mycoplasma gallisepticum

Clinical signs of infection by Mycoplasma gallisepticum include the following:

  • Coughing
  • Sneezing
  • Shaking of the head
  • Rales
  • Gasping
  • Discharge from the eyes
  • Discharge from the nose
  • Swelling of the face and/or wattles
  • Retarded growth
  • General diarrhea
  • Prostration

Mycoplasma synoviae

Clinical signs of infection by Mycoplasma synoviae include the following:

  • Sneezing
  • Shaking of the head 
  • Rales
  • Discharge from the eyes
  • Discharge from the nose 
  • Swelling of the face and/or wattles
  • Retarded growth 
  • Lameness
  • Green, watery diarrhea
  • Swollen joints

Mycoplasma meleagridis

Clinical signs of infection by Mycoplasma meleagridis include the following:

  • Coughing
  • Sneezing 
  • Rales
  • Retarded growth
  • Twisting of the head and neck (torticollis)

Connect with us

  • Facebook
  • YouTube


This is where you can find research-based information from America's land-grant universities enabled by



This work is supported by the USDA National Institute of Food and Agriculture, New Technologies for Ag Extension project.