Coccidiosis in Chickens

Coccidiosis is a common, potentially deadly disease that is spread through the environment, primarily through infected litter. It is normal for chickens to peck their surroundings. Therefore, the more contact the flock has with fecal material on the ground, the greater their chance of contacting coccidiosis. Coccidiosis is more prevalent in the spring and summer when conditions are warm and wet. It is also species specific, therefore, the species that infects chickens does not infect other animals and vise versa.

The life cycle of protozoan parasite genus Eimeria (coccidia)

It is normal for chickens to have some exposer to coccidia throughout their lives. This gradual exposure over time helps the birds build immunity. However, young chickens or birds suddenly exposed to ground litter have a high chance of becoming severely ill or dying from coccidiosis. There are nine species of protozoa that can infect chickens. Therefore, a flock that is exposed to one type of coccidia in the environment can still be infected and have no immunity to the other protozoa species.

  • Un-thriftiness
  • Diarrhea, sometimes bloody
  • Weakness

    Symptoms include: weakness and lethargic
  • Decreased appetite
  • Decreased water intake
  • Slow growth rate
  • Loose, watery, or off-colored stool
  • Decreased egg laying
  • Advanced cases will result in a high mortality rate of the flock


If you are concerned that your flock might be infected with a type of coccidia you can take a fecal sample to your local veterinarian for testing. This will also help determine which of the nine species have infected your chickens and which medications would be most effective. The best way to prevent coccidiosis is through sanitation.

Spray cabinet

A good management practice is to change soiled litter frequently, especially wet litter. Coccidiosis vaccines for chickens include Coccivac®-B and Paracox®-5. Vaccines are often given to young birds prior to three weeks of age and can be administered by:

The use of coccidiostats in medicated feeds are another preventative measure of coccidiosis. There are many commercial drugs that can be used in chickens such as:

  • Amprolium
  • Ionophores
  • Nicarbazon
  • Quinolones
  • Robenidine

*Always make sure to read and follow label directions when administering any drugs.


Posted: December 29, 2020

Category: Agriculture, Livestock, Pests & Disease, UF/IFAS Extension
Tags: Backyard Chickens, Chickens, Coccidiosis, Flock Care, Topic Tuesday

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