Coccidiosis of turkeys and broiler chickens Literature review

Background: During intensive livestock farming prevention of protozoa infection is becoming increasingly difficult due to the limited use of chemotherapeutic agents and the lack of available vaccines. Coccidiosis is prevalent worldwide and is one of the most common diseases in the intensive poultry industry in Hungary. Coccidiosis can cause high mortality however the subclinical form of the disease, which results in a lack of weight gain and a need for increased feed consumption, has become a much greater threat to local economies. The intensive broiler chicken and turkey industry is affected severely from this disease that subsequently causes huge economic loss to farmers. Objectives: Based on current literature the authors summarise the history and aetiology of subclinical coccidiosis and the lifecycle of the Eimeria-spp. They describe the epidemiology, clinical signs and assess the different techniques used to diagnose the disease including those utilised in the field (such as total mean lesion scoring) and laboratory techniques (faeces examination, oocyst counting technique, flotation, polymerase chain reaction). They explain the aspects of therapy and prevention options, such as vaccination (live vaccines, attenuated vaccines, subunit vaccines) and the resistance against different anticoccidial drugs. They discuss the possibility of using various alternative natural extracts (such as antioxidants, pre- and probiotics, sugar-beet extracts etc.).