Control of Coccidiosis

Aside from strict bio-security and good zoo-hygiene conditions, there are currently two well established methods of coccidiosis prevention used, namely: the use of anticoccidial drugs and live vaccines. Usually when clinical coccidiosis has been diagnosed the coccidian parasites have already gained a strong-hold so much so that in the end therapeutic intervention is normally not sufficient in preventing massive economic losses. Thus, the concept of prevention emerged to avoid economical losses caused by coccidian infections.


Anticoccidials have been used successfully since the late 1940s. Until the 1980s, they were the main means of controlling coccidiosis. The advantages of using anticoccidials are that they have a wide spectrum of activity, and are easily applied. However, continuous application and mistakes in their mixing in feed resulted in their incorrect concentration use and led to the development of resistance by the parasite to all the anticoccidial drugs available on the market. The introduction of rotation and shuttle programmes (shifting from one drug to another) were then designed to reduce the tolerance of the parasite to these drugs; despite this effort only short term alleviation was achieved and the overall problem of resistance remained.

Anticoccidials suppress induction of immunity in the chickens. Furthermore anticoccidials leave residues in the products (meat and eggs), are incompatible with some other drugs used in poultry husbandry (e.g. with thiamulin and some other antibiotics) and are toxic for some animal species. In some countries, for example those belonging to the European Union, some anticoccidials are banned and for anticoccidials that are allowed there is an obligatory withdrawal period just prior to slaughter.
Consequently, the need to move away from chemotherapeutics led to the development of coccidiosis vaccines as a natural and biological means of controlling coccidiosis by avoiding the shortcomings experienced when using anticoccidial drugs.


There are two types of vaccines that are available on the market, namely: non-attenuated (virulent) and attenuated vaccines.

Non-attenuated vaccines contain live, virulent coccidian oocysts, i.e. the chickens are exposed to the fully pathogenic parasites from the vaccine in addition to field virulent coccidia spread in the poultry house. Therefore, when using these vaccines, there is a risk of strong post-vaccination reaction and of clinical coccidiosis outbreak especially in birds with a suppressed immune system. Hence after the administration of virulent vaccines the preventive treatment with anticoccidials is often necessary and recommended to be applied even by the manufacturers of these vaccines.

Attenuated vaccines, i.e. vaccines of the second generation, contain live oocysts of attenuated lines of Eimerian species. These vaccines are much safer due to the biologically attenuated pathogenicity of the vaccinal parasites, and controlled infectious challenge thus posing no risk of clinical coccidiosis outbreak.
LIVACOX® vaccines belong to the group of attenuated vaccines.