Epidemiology of Gastrointestinal Parasites of Cattle in Three Districts in Central Ethiopia

Abstract

Parasitic diseases are a major impediment to livestock production worldwide. However, knowledge about the epidemiology of gastrointestinal parasites in many low-income countries is still limited. An epidemiological survey on these parasites in traditionally reared cattle was performed in central Ethiopia (West Shewa Zone), from September 2019 to November 2021. Overall, 691 samples were analyzed qualitatively (flotation technique) and quantitatively (McMaster technique) to detect helminth eggs and <i>Eimeria</i> oocysts. Furthermore, coprocultures were conducted on pooled samples to identify the genera of gastrointestinal strongyles (GIS). The difference in prevalence according to agroecology, season, age, sex and body condition score (BCS) was investigated using univariable tests and through a multivariable logistic regression analysis, whereas abundance values were interpreted using a descriptive approach. The highest prevalence values were observed for GIS (50.2%) and <i>Eimeria</i> spp. (36.0%), whereas <i>Moniezia</i> spp. (16.3%), <i>Strongyloides</i> spp. (5.1%) and <i>Schistosoma</i> spp. (4.2%) showed lower values. <i>Trichuris</i> spp. and <i>Toxocara vitulorum</i> were sporadically found. A coproculture revealed that <i>Haemonchus</i> spp. (34.6%), <i>Trichostrongylus</i> spp. (25.9%) and <i>Bunostomum</i> spp. (19.1%) were the most frequent genera of GIS. A poor BCS was strongly associated with the occurrence of GIS, while seasonal variations were detected for <i>Eimeria</i> spp., GIS, <i>Moniezia</i> spp. and <i>Schistosoma</i> spp., with a higher prevalence and burden during the rainy season, and agroecology also strongly influenced different parasitic taxa. This present study increases the knowledge about the epidemiological features of gastrointestinal parasites in the context of a low-income country, suggesting a more tailored approach for their control. The use of a BCS as an indicator for the selective treatment of highly infested animals is supported by our findings, introducing a possible way to prevent anthelmintic resistance in areas where basic diagnostic services are rarely used by farmers.