Oestrus ovis infection of grazing sheep during summer in southern Chile

Abstract

ABSTRACT. - Oestrus ovis is a botfly whose larvae cause nasal myiasis, an environmental-dependent disease in small ruminants, generating acute and chronic injuries in the cranial cavities of sheep. Chile is a country of the southernmost worldwide distribution of this parasite, and there is few information about. Whence, the objective of this study was to approximate the epidemiological situation of O. ovis infection in Chilean sheep. From December 2009 to March 2010, a total of 87 samples were obtained by necropsy for skull inspection. The larvae were collected, and microscopically identified. The prevalence in the sampled sheep was 60.9%. From those that were infected, 85.7% (18/21) of sheep were 1 to 3 years old, constituting the stratum with the highest prevalence. The difference of infection in females and males was not significant. The high risk of infection seems to be dependent upon the environmental conditions of this southern region, especially during summer when the first larval stage (L1) could be found as the evidence. Therefore, the disease should be considered as a significant problem for this kind of livestock production.

Prevalence and intensity of Oestrus ovis in sheep and goats in south-eastern part of Turkey

“…(2015) and Hidalgo et al (2015). Mean larval burden in goats was similar with that reported by Papodopolus et al (2010) and lower than reported by Gebremedhin (2011).…”

Oestrus ovis in Ecuador: Importance in the Andean sheep farming

“…Our findings showed 19% of the prevalence of O. ovis in the highlands of Ecuador. Previously, other studies carried out in South America showed a prevalence of oestrosis of 13.7% and 16.9% in Brazil [10,21], 60% in Chile [12], and 33.4% in Mexico [14]. All these studies were carried out in different geographical and ecologic zones with different climatic conditions to our study.…”

“…Oestrosis is present in different regions and habitats and has been reported worldwide, i.e., in the Mediterranean countries of Europe and Africa [8,9], Asia, and India [1,5]. In America, this parasite was found from California to the Patagonian regions, including Central America [10-12], as O. ovis activities appear to be accustomed to high temperatures (25-28°C), strong solar radiation (116-838 Wm −2 ), and a wide range of the relative humidity (65-85%) [13]. Besides, a high prevalence was found in tropical sub-humid sites where temperature, annual rainfall, and humidity were 26°C, 900 mm, and 60-80%, respectively [14].…”

The global and regional prevalence of oestrosis in sheep and goats: a systematic review of articles and meta-analysis

“…Among the selected articles, 18 articles reported the prevalence of oestrosis in both sheep and goats [1, 7, 21, 23, 29–42], 40 articles in sheep [3, 19, 20, 22, 43–78] and 8 articles reported only in goats [79–86]. Based on the origin of samples, 50 studies were from abattoirs [3, 19–22, 29–41, 43, 45–63, 65, 70, 73, 75, 77, 79–85], 10 from farms [1, 44, 64, 67–69, 74, 76, 78, 86], 3 from free ranging flocks [66, 71, 72] and 3 from mixed flocks [7, 23, 42]. Based on the method of diagnosis, 56 studies used necropsy [1, 19–22, 29–38, 40–63, 65, 66, 70–77, 79–85], 4 used ELISA [7, 23, 64, 69] and 6 used combined or other methods [3, 39, 67, 68, 78, 86].…”