Fowl Pox

Avian Fowl Pox is a viral disease that causes canker-like sores affecting the skin, mouth and throat.   The disease is best controlled through vaccination.  Control of the disease can be difficult since mosquitoes spread Fowl Pox between birds and are secondary carriers of the disease.   There are two forms of Fowl Pox; Dry or Cutaneous Pox affects the skin, and Wet or Diphtheritic Pox primarily affects the mouth and throat.   Particularly virulent strains can cause a systemic form affecting internal organs, though this is less common.   



            Most birds, including:                        

  • Chickens 
  •  Ducks
  • Geese
  • Pheasants
  • Pigeons
  • Quail 
  • Turkeys

Where:  Worldwide; common anywhere poultry is raised; in particular confined populations during winter and spring

When:  Any age

Why:  Virus - DNA avian pox   


  • Contact with and/or consumption of shed scabs
  • Direct bird-to-bird contact
  • Spread by air (wet)
  • Spread by infected mosquitoes
  • Through skin injuries
  • Virus can survive for months outside the host, particularly in the shed scabs.


            Dry Pox Symptoms:

  • Raised/white wart-like bumps on un-feathered areas, particularly on comb, wattles, ear lobes, and eyes.  Occasionally on feet and vent. 
  • Reddish brown/black/gray bleeding scabs
  • Shedding of scabs prior to healing
  • Un-thriftiness
  • Drop in egg production

            Wet Pox Symptoms:

  •  Clear/white bumps on face
  •  Conjunctivitis
  • Coughing
  • Diphtheritic lesions in mouth and trachea
  • Rattling breath (rales)
  • Sneezing
  • Suffocation due to lesions in mouth and throat


Treatment:  None.  Cull birds that show symptoms.  The disease is slow spreading, so vaccination can protect birds that have yet to show signs, and can prevent a large outbreak. 


Vaccine:  Yes (click here for more information) 

  • Typically vaccination of day-old chicks.     
  • Vaccine can stop outbreaks.
  • Wing-web vaccination for chickens 
  • Feather-follicle method for turkeys 

Pesticides:  Useful to control mosquito populations in closed flocks. 


Also Known As

  •  Avian Pox
  • Chicken Pox (not the human form)
  • Fowl diptheria
  • Fowl Pox
  • Sore head

Affects:  Skin (dry pox); mouth and upper respiratory tract (wet pox)

Clinical Diagnosis:  Identified by the presence of wart-like bumps typical of fowl pox.   Can be confirmed by testing scabs for the virus, but this is usually unnecessary. 

Diseases with similar symptoms: 

  • Canker     
  • Infectious Laryngotracheitis       
  • Physical wounds to head

Duration of symptoms:  prolonged and slow duration; affects a bird for 3 to 5 weeks

Incubation:  4 to 10 days 

Morbidity:  10 to 95%

Mortality:  Low(<10%) for dry pox, to moderate(10 to 49%) for wet pox

Transmission to people:  No. 


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A righteous man cares about his animal's health...

Proverbs 12:10a