Disinfectants (or lack thereof)

In contrast to widely available disinfectants effective against many bacteria and viruses, very few substances and situations can either kill or decrease the viability of Eimeria species or can effectively kill coccidial oocysts in a reasonable amount of time (i.e. minutes rather than hours/days) and are not highly corrosive and/or toxic. Unfortunately, these agents are extremely harsh and can be detrimental to the bird.

Examples of substances or situations that can impact Eimeria species are (1-5):

 Substances or Situation

 Effect on Eimeria

 Effect on bird

 Fumigation Ammonia, paraformaldehyde

 One of the few substances able to penetrate the oocyst wall and stop sporulation and/or kill the oocyst.

 Ammonia fumes can burn the eyes and the inside of the throat of the bird. Formaldehyde will fix the lungs and kill the bird.

 Oxygen access

 Sporulation will not occur without oxygen.

 Birds cannot survive without oxygen.

 Ultraviolet radiation (sun exposure for an extended period of time)

 Can stop the ability of the oocyst to sporulate or stop the ability of a sporulated oocyst to infect a host.

 Unfeathered parts can burn which can cause pain for the bird. 


 A hard freeze can kill the oocyst.

 Unfeathered parts can freeze which can injure the bird. If the frozen section thaws this causes pain for the bird.

 Desiccation (drying)

 The oocyst wall will shrink due to water loss and sporulation cannot be completed properly.

 A dry environment can have a negative impact on chicken welfare (e.g. mortality, physiology, behaviour).

 High temperature (over 37°C)

 Sporulation is unable to be completed and/or the oocyst will be killed.

 Increased heat can cause heat stress which can lead to death if left untreated.


 Bacterial breakdown of litter can produce a local litter environment lacking oxygen which can stop sporulation.

 Depending on the species of bacteria present and whether or not the birds are susceptible to infection, presence of bacteria can induce bacterial infections.

If the flock has access to outside (e.g. a grass run) and the birds remain near the housing building or within the barn, there may be potential for a heightened disease risk due to higher transmission associated with local increased bird density (6).  Nevertheless, how the outdoor run is designed and managed may influence Eimeria transmission.  


1. Reyna, P.S., L.R. McDougald, and G.F. Mathis. Survival of coccidia in poultry litter and reservoirs of infection. Avian Diseases 27:464-473. 1983.

2. Daugschies, A., B. Bangoura, and M. Lendner. Inactivation of exogenous endoparasite stages by chemical disinfectants: current state and perspectives. Parasitology Research 112:917-932. 2013.

3.  Marquardt, W.C., C.M. Senger, and L. Seghetti. The effect of physical and chemical agents on the oocyst of Eimeria zurnii (Protozoa, Coccidia). Journal of Protozoology 7:186-189. 1960.

4. Peckham, M.C. Vices and Miscellaneous Diseases and Conditions. In: Diseases of Poultry. M.S. Hofstad, H.J. Barnes, M.W. Reid and H.W. Yoder Jr., eds. Iowa State University Press, Ames, Iowa, USA. pp 741-782. 1984.

5. Reid, M.W., P.L. Long, and L.R. McDougald. Coccidiosis. In: Diseases of Poultry, 8 ed. M.S. Hofstad, B.W. Calnek, M.W. Reid and H.W. Yoder Jr., eds. Iowa State University Press, Ames, Iowa, USA. pp 692-717. 1984.

6. Fanatico, A.C. Organic Poultry Production in the United States. In: ATTRA publication. NCAT, Fayetteville, AR. 2008.