Epidemiology of Eimeria infections in sheep raised extensively in a semiarid region of Brazil

Abstract

The aim of this study was to identify and determine the prevalence of Eimeria species affecting sheep raised extensively in a semiarid region of Brazil. Fecal samples of native sheep were collected during the rainy and dry seasons. The degree of infection was determined by counting oocysts per gram (OPG) of feces, and the morphometric method was used for species identification. Oocysts were found in all the properties assessed, in which 68.3% of the animals were infected. The prevalence of oocysts was influenced by the season and animal category (P<0.05). It was higher during the rainy season than the dry season (80.2% vs. 55.8%) and highest in young animals than the adults animals (68.2% vs. 39.6%). The OPG was lower during the dry season (1,269 ± 312 vs. 4,400 ± 1,122). Ten species were found; of these, E. ovinoidalis, E. granulosa, E. faurei, and E. crandallis were the most frequent. E. ovinoidalis and E. crandallis were found in all properties, with their prevalences being 19.4% and 13.6% respectively. The high prevalence of pathogenic species shows that eimeriosis is a risk for animals raised extensively in the semiarid region.Keywords: Coccidiosis, morphometry, oocyts, OPG, parasitosis. ResumoObjetivou-se neste estudo identificar e determinar a prevalência de espécies de Eimeria que parasitam ovinos criados extensivamente em região semi-árida. Amostras de fezes de ovinos nativos foram coletados durante as estações chuvosa e seca. O grau de infecção foi determinado pela contagem de oocistos por grama de fezes (OoPG)e o método morfométrico foi utilizado para a identificação das espécies. Foram encontrados oocistos em todas os rebanhos avaliados e observou-se que 68,3% dos animais estavam infectados. A prevalência de oocistos foi influenciada pela estação climática e pela categoria dos animais (P<0,05), sendo mais alta durante a estação chuvosa em relação a estação seca (80,2% vs. 55,8%) e em animais jovens em relação aos animais adultos (68,2% vs. 39,6%). O OoPG foi menor durante a estação seca (1.269 ± 312 vs. 4.400 ± 1.122). Dez espécies foram encontradas sendo a E. ovinoidalis, E. granulosa, E. faurei, e E. crandallis as mais frequentes. E. ovinoidalis e E. crandallis foram encontrados em todas as propriedades, com prevalências de 19,4% e 13,6%, respectivamente. A alta prevalência de espécies patogênicas mostra que eimeriose é um risco para os animais criados extensivamente na região semiárida.

Eimeria spp. infection in lambs from southern Brazil

“…The results obtained in this research showed that the Eimeria species has a wide distribution in the study area. Brazilian and worldwide studies have found a variable prevalence of Eimeria species in sheep; however, in the majority of cases, young animals had higher rates of positivity for the parasite (Lopes et al 2013, Souza et al 2015, Carrau et al 2018. The high prevalence of positive samples found in the present study (85.98%) probably occurred due to the focus on young lambs, the age group most susceptible to coccidiosis.…”

“…E. ahsata, E. bakuensis, E. granulosa, E. faurei, E. parva, E. pallida, and E. punctata are considered nonpathogenic but can cause impairment of growth due to nutrient malabsorption (Keeton & Navarre 2017, Taylor et al 2017, which might trigger subclinical coccidiosis in animals. Investigations carried out in different regions of Brazil already describe the presence of these species infecting sheep with variable prevalence (Tembue et al 2009, Silva et al 2011, Lopes et al 2013, Souza et al 2015, Macedo et al 2019 Previously studies demonstrated that the intensive and semi-intensive farming systems could facilitate the dissemination of Eimeria species (Lopes et al 2013, Tomczuk et al 2015. In this study, there were statistical differences (p=0.028) between animal infection and different breeding systems.…”

“…In samples with less than 100 oocysts, all were analyzed. Species differentiation was based on morphometric and morphological characteristics, such as: shape, color, and presence or absence of micropyle and micropylar caps, following Souza et al (2015) and Macedo et al (2019). For descriptive analysis, the Excel ® 2019 software package was used.…”

Prevalence and risk factors of gastrointestinal parasites in sheep from Ubaté, Cundinamarca, Colombia

“…Those results can also be due to the production system because infection intensity of oocysts is influenced by two factors: intensity of animal production and the coccidiosis carrier-state in dams, which are the main source of infection to young (Cai & Bai., 2009). If animals are in a higher density, feces-urine fouled forage, sheep raised in confinement and semi-confinement conditions could be more heavily infected with coccidia than those grazing on pastures (Souza et al, 2015). In further studies is important to take into account the grazing conditions of the animals because it could be a risk factor.…”

“…Around the world, the reported gastrointestinal nematodes affecting sheep and goats include: Haemonchus, Trichostrongylus, Teladorsagia/Ostertagia, Strongyloides, Bunostomum, Nematodirus, Chabertia, Trichuris, Cooperia, Skrjabinema and Oesophagostomum, and the general prevalence estimate is 75.8% (Asmare et al, 2016).On the other hand, the main species of coccidia in sheep are Eimeria ovinoidalis, E. crandallis, E. ahsata and E. parva in sheep (Souza et al, 2015).…”