Prevalence and Associated Risk Factors of Eimeria in Sheep of Punjab, Pakistan

Given the lack of information about Eimeria elephantuli due to its recent discovery, the presence and prevalence of Eimeria in sheep is covered in this article. There are fifteen species of Eimeria which are considered to have the capability to infect sheep and cause the disease coccidiosis, the most pathogenic of which are E. ovinoidalis, E. bakuensis, and E. ahsata (Khan et al. 2011). Coccidiosis can have a negative impact economically, particularly for sheep farmers whose animals are used for markets with a particular demand such as textiles, due to the profit loss from animal death, treatment cost, and the cost to take measures to control the spread of the protozoan. All sheep are vulnerable to the infection, but lambs are impacted the most by the disease, especially when they are being weaned off of their mother’s milk (Khan et al. 2011).

Four hundred and eighty six sheep from Pakistan were observed in the study, with their associated farmers filling out questionnaires that inquired about perceived risk factors including: age, breed, sex, climate, and husbandry and management. There were two age groups, four breeds, four seasons, three feeding systems, two housing systems, two floor patterns, two watering systems, and two herd sizes created for testing based on the questionnaires (Khan et al. 2011). The identification of different species of Eimeria found in the sampled sheep was based on the morphological features of the oocysts of the parasite. These features included but were not limited to: size, shape, color, and texture of the oocyst wall, as well as reference to taxonomic keys (Khan et al. 2011).

Fourty-three percent of the sheep sampled were infected with some species of Eimeria, with five different species being found in those sheep. The most common species was E. ovinoidalis followed by E. ahsata, E. intricata, E. parva, and E. faurei. The rainy season had the highest recorded incidence of parasitic infection, with lambs generally having a higher infection rate than adult sheep (Khan et al. 2011). Statistical analysis found that the age, sex, season, housing system, floor type, watering system, and herd size were the factors that were significantly related to the prevalence of Eimeria infections. Housing system stood out as being one of the biggest risk factors of infection, with just over 50% of animals in a closed housing system being infected compared to the 30% of animals that were infected in an open system of housing (Khan et al. 2011).

Coccidiosis increases in the post rainy season because the wet and humid climate is perfect for the parasite to reproduce. Animals in contaminated quarters, who are overcrowded, or whose drinking water can be contaminated by fecal matter also have a higher prevalence of infection compared to those that live in better hygienic conditions (Khan et al. 2011).

References

Khan, M., Rehman, T., Iqbal, Z., Sajid, M., Ahmad, M., Riaz, M. 2011. Prevalence and associated risk factors of Eimeria in sheep of Punjab, Pakistan. World Academy of Science, Engineering & Technology. 79: 443-447.