Coccidiosis occurs in poultry that are infected by ingesting sporulated oocysts from different species of Eimeria. Only sporulated oocysts are infectious, and the sporulation process requires specific environmental conditions. 

These factors are crucial for the prevention of coccidiosis, as good practices such as adequate ventilation and effective management of drinking troughs can keep the litter in the houses with lower moisture content and interrupt the accelerated sporulation of oocysts, thus reducing the number of sporulated oocysts. 

To complement this work, antimicrobials or antiprotozoals have also been used for decades to prevent and treatment of coccidiosis.  

Mycotoxins: a critical factor in coccidiosis in poultry

Mycotoxins present in poultry feed, even at permitted levels, tend to aggravate the incidence of coccidiosis in chickens, ducks, and turkeys, as they can facilitate the colonization of Eimeria in the intestine. 

Therefore, strict feed control is recommended as a strategy. Deoxynivalenol and fumonisins, for example, interfere with several vital cellular functions that protect against pathogens such as Eimeria.  

Most common methods of prevention and treatment of coccidiosis

Coccidiostats for short life cycles 

Due to the short life cycle of broiler chickens, the most widely used coccidiosis prevention program aims to completely eliminate Eimeria from the intestines of poultry through the use of anticoccidials in feed. 

Prophylactic use is preferable, as most of the damage caused by Eimeria occurs before signs appear, making it difficult to control an outbreak of the disease with coccidiostats. 

Coccidiostats for long life cycles  

For breeders and layers, which have a longer life cycle, the goal is usually to develop protective immunity in animals. This allows for minimal exposure to the protozoan and the use of coccidiostats to interrupt the development of the parasites, thus seeking a balance between intestinal damage and the minimum exposure necessary for the development of immunity.  

The weaknesses of using only these methods for avian coccidiosis are:

1. Once coccidiostats are discontinued, infectious parasites can resume their life cycle, producing clinical manifestations of the disease. 

2. The use of coccidiostats in poultry for an extended period can result in the emergence of strains of coccidia that are resistant to these compounds. 

To avoid these issues, different treatment programs for coccidiosis are used. For example, a common practice to eliminate parasites that have shown resistance to a single antimicrobial is to use rotating anticoccidial programs that alternate during different periods of the poultry’s life.

Natural immunity and species specificity 

Natural immunity is generated after infection with Eimeria in poultry. However, it is important to note that it is acquired gradually and is not complete until birds are 6 weeks of age—42 days of critical risk. 

Immunosuppressive diseases, such as Marek’s disease and infectious bursal disease (IBD), interfere with the development of immunity, making infected birds more susceptible to coccidiosis. 

It is also important to highlight that immunity is species-specific for each Eimeria and that there is no cross-protection between species, except for some cross-protection between E. maxima and E. brunetti. 

Conclusion 

Prevention and treatment of coccidiosis in poultry are essential to maintain the health and productivity of your flocks. Implementing appropriate practices and choosing the most efficient methods can significantly reduce the impact of this disease. To do this, the approach needs to be well planned and adapted to the specific conditions of each production system.  

Want to discover more strategies and deepen your knowledge of natural alternatives?  

Don’t miss the continuity of this series, where we explore natural and combined strategies for treating coccidiosis in poultry in detail. 

Your proactivity can make all the difference!