October 22, 2016

Coccidiosis in Chickens

Coccidiosis is a parasitic disease of the intestinal tract caused by the coccidian protozoa, a single cell organism. Chickens are susceptible to some 11 species of these coccidia, the most common however being Eimeria tenella. As the coccidia reproduce inside the chicken’s intestine they cause bleeding and swelling.

How do Birds Become Infected?

The disease spreads from one animal to another by contact with infected faeces or ingestion of infected tissue. Normally, most birds pass small numbers of parasitic eggs, or oocysts, in their droppings without apparent ill effects. However the problem really occurs when chickens are reared in conditions that permit the build-up of infective oocysts. For example the intensive chicken rearing methods used by some industry members often provide such ideal conditions. Oocysts can remain viable in litter for many months. Coccidiosis occurs most frequently in young birds, older birds are generally immune as a result of prior infection.


Coccidiosis can cause severe damage to the chickens small intestine  and infected birds lose a lot of liquid, cannot absorb nutrients from their food and will quickly die if left untreated.  The most obvious symptom is bloody droppings, in addition the chicken will often have white diarrhea around its vent, it will lose weight and will have a hunched up appearance with ruffled feathers.


If you suspect Coccidiosis you should consult a veterinarian immediately, who will be able to advise on an authorised drug and the prescribed egg withdrawal period ( (i.e. eggs must not be eaten) for that drug.  Additionally  Coxoid is a widely available treatment.  Coxoid is administered in the drinking water for seven days, egg withdrawal period 28 days. Severely infected birds may need the medicine administered by small syringe or pipette (a straw also works well).

You must clean the chicken house, run (and the ground they live on) and all utensils with a disinfectant such as Bi-OO-Cyst which will kill all coccidial parasites. Regular use of this will prevent any further infection as parasites can live in empty houses and the ground for several months. 

Preventing Coccidiosis

Good management practices are the best way to control coccidiosis. Here are some:

  • Avoid overcrowding.
  • Keep food and water away from droppings.
  • Try to avoid mixing different age groups of birds.
  • Keep chicks off areas where older birds have been.
  • Roost birds over netting if possible to trap droppings.
  •  Most chick crumbs and growers pellets contain Anti-Coccidiostats (ACS) that can protect against Coccidiosis.
  • Place water vessels on wire frames to reduce spillage leading to wet droppings, in which the chicks can walk and pick up or spread the disease.
  • Keep litter dry and replaced frequently.
  • If coccidiosis does break out, seek advice from a poultry vet.