Avian Intestinal Spirochaetosis Bra ...

Avian Intestinal Spirochaetosis Brachyspira species infection in Laying Hens

Avian Intestinal Spirochaetosis Brachyspira species infection in Laying Hens

The “mild to moderate” disease spectrum is seen particularly in association with strains of  B. intermedia, B. pilosicoli and B. alvinipulli  mainly in laying hens and broiler breeder hens. This infections tend to be associated with diarrhea and/or reduced egg production but cecal changes are mild or inapparent.

Brachyspira pilosicoli was associated with a reduction in egg production, diarrhea in up to 25%, wet droppings, feces smeared on feathers around the vent ('pasty vents'), lethargy and depression.

Brachyspira alvinipulli was associated where 5% of the hens had wet feces, clinical diarrhea, pasty vents and produced dirty, fecal-stained eggshell. Experimental infection resulted in yellow, golden or orange cecal droppings.

Observed Clinical Signs Happenings

Egg Drop

  • Egg production declines gradually ( B. intermedia, B. pilosicoli and B. alvinipulli  )
  • Reduced egg production (B. intermedia, B. pilosicoli and B. alvinipulli  )
  • Slight reduction in egg production  (B. intermedia)
  • 5% reduction in egg production (B. pilosicoli) and or B. alvinipulli )
  • Significantly fewer eggs (B. intermedia)


  • Intermittent chronic diarrhea, which typically may be seen in 5-20% of a flock ( B. intermedia, B. pilosicoli)
  • Wet droppings with the increased serum content of protein, lipid, carotenoids and biliruben (B. intermedia)
  • Increased fecal water content ( B. intermedia, B. pilosicoli and B. alvinipulli  )
  • Increased fecal fat content (B. intermedia)
  • The ceca were gassy and the contents were frothy, fluid and pale (B. pilosicoli)
  • Slimy, wet, frothy faeces (B. intermedia)
  • Pasty vents (B. alvinipulli )
  • Feces may be yellowish-brown, mucoid and/or foamy, which increases in both lipid and water (around 15%) content.


  • Feces smeared on feathers around the vent ("pasty vents")  (B. alvinipulli )
  • Dirty feathers with droppings around the vent or Pasty vents (B. intermedia, B. pilosicoli)

Shell quality

  • Dirty fecal-stained eggshells (B. alvinipulli )
  • Egg weight reduced
  • Egg significantly lighter eggs (B. intermedia)
  • Eggs from infected hens become stained with faeces,  (B. pilosicoli ,B. intermedia)

Internal Egg Quality

  • Paler yolks (B. intermedia)
  • Yolk colour decreased or yolk discoloration or paler yolks (B. intermedia)


Avian Intestinal Spirochaetosis Brachyspira species infection in Laying Hens in Laying Hens DOES NOT exhibit or manifest any of the following clinical signs happenings:

  1. Egg production declines rapidly
  2. Mortality above the standard
  3. Visibly sick birds
  4. Flock behaviour activity change
  5. Respiratory abnormalities
  6. Neurological Nervous
  7. Lameness or unusual movements, incoordination, ataxia
  8. Eyes abnormalities
  9. Head, Comb, Wattles, Face, Nostrils, Sinuses, Mount, Beak, Ear lobes, abnormalities (except eyes)
  10. Body Parts (Neck, wings, breast, abdomen, shanks, legs, hocks, feet, joints, vent, and skin, abnormalities), skinny body, retarded growth, weight depression
  11. Feed Consumption Changes
  12. Diet or Feed Changes (Recent Feed delivery, Recent formulation /diet, Other silo or improper storage, another  feed brand)


Causing Agents
Bacterial Intestinal Infection. Brachyspira intermedia. Brachyspira pilosicoli. Brachyspira alvinipulli.
Affected Systems/Organs
Digestive System. Large Intestine, ceca.
Transmission via arthropods, droppings
Mainly Affects
Egg Production and Egg Quality
Drug therapy. Vectors control. Biosecurity
Suggested Actions
  • Can be confirmed with clinical signs and gross lesions
  • Can be managed with feed additives, off-the-shelf medications
  • Diagnosis should be confirmed with rapid assays and/or a certified laboratory
  • Veterinary intervention is recommended

Impact on Egg quality


Impact on Liveability


Impact on Production


Overall Economic Impact


Y.M. Saif.2008.Disease of Poultry. 12th Edition.page 929

David E. Swayne. 2013.  Diseases of Poultry 13th Edition. page 1001

Mark Pattison, Paul F. McMullin, Janet M. Bradbury. Dennis J. Alexander. 2008. Poultry Diseases. 6th Edition.

Paul McMullin. 2004. A pocket Guide to Poultry Health and Disease. First Edition.

Steven Leeson, John D. Summers. 2008. Commercial Poultry Nutrition. Third Edition.

Donald D. Bell, Williams D. Weaver. 2009.  Commercial Chicken Meat and Egg Production. Fifth Edition.

AVES © 2015                   Privacy Policy | Terms of Use