When decisions concerning the prevention or control of coccidiosis in poultry are based on the subjective scoring of macroscopic lesions, observed in the gut of a number of birds in a flock, several factors affecting the method should be considered. Proper selection of birds, a careful sampling procedure and sample handling along with an accurate judgment of lesions, are some of the most important methodological indicators for success in lesion scoring during a flock inspection.
1. Selection of the right birds in the right number:
Before necropsy, it is essential to check the history of vaccinations, treatments (anticoccidials in particular) and previous diagnoses of the flock to be sampled. It has been shown that the existence of gut lesions is not necessarily accompanied by clinical signs of coccidiosis in poultry (Williams et al., 2000).
Continue reading Key points in the diagnosis of coccidiosis (Part 2: Lesion Scoring)
The prerequisite for the control and treatment of coccidiosis in poultry is to correctly identify the presence of disease. Two of the most widely used methods for this purpose are the identification and enumeration of oocysts, and the identification of lesions in the intestine. Although egg identification and counting was described for decades, and has been used since then, it is important to consider some key aspects of the method to obtain valid results.
1) Be familiar with the morphology of the parasite:
Have skills to identify the Eimeria species is the main element to be considered for the success of the morphometric study of field samples. For this, it is convenient to train yourself using pure parasite suspensions obtained in the laboratory.
Continue reading Key points in the diagnosis of coccidiosis (Part 1: Identifying and counting oocysts)
In the fight against infectious diseases, the first step is the correct identification of the causative agent, and the symptoms and lesions that it causes in the host. A correct diagnosis influences on the effectiveness of the treatment established, particularly if it is combined with preventive measures such as vaccination. Traditional techniques such as microscopic observation and oocysts counting remain very useful as screening methods, and an aid in the diagnosis and treatment of coccidiosis in animals. DNA-based methods such as PCR have overcome some limitations of these conventional methods, allowing the analysis of more samples in less time, increasing sensitivity and allowing the quantification of the parasite in one step.
These new methods positively influence the treatment of coccidiosis, expanding the possibilities for the poultry veterinarian to control the disease.
Continue reading Contribution of DNA-based diagnostic methods to the treatment of coccidiosis in poultry. What’s New?