Seasonal variation of strongylosis in working donkeys of Ethiopia: a cross-sectional and longitudinal studies

Abstract

Helminths are one of the major health problems of working donkeys, often with heavy worm burden and contributing to their early demise and/or reduction in their work output. Cross-sectional and longitudinal studies were conducted to investigate the current infection prevalence and level of strongyles infection donkeys would acquire through different seasons in the mid-lowland agro-ecological zones of Ethiopia. For this purpose, faecal samples from 206 (cross-sectional study) and 102 (longitudinal study) randomly selected donkeys were directly collected from the rectum and analysed. For the longitudinal study, the 102 donkeys dewormed at the end of main rainy season, beginning of October, were monitored for the level of strongyle infection they would acquire during subsequent dry and short rainy seasons. The cross-sectional study of 206 donkey has revealed an overall infection prevalence of 89.3% (95% confidence interval (CI) = 84.4, 92.9). Donkeys in the lowland zone showed a significantly higher strongyle infection prevalence (P = 0.0126) and mean eggs per gramme of faces (EPG) (P = 0.001; 2775 EPG) compared to donkeys in the midland zone (980.8 EPG). Age, sex and body condition did not have any significant effect on either the infection prevalence or level of infection (P > 0.05). The longitudinal study has shown a significantly lower strongyle infection prevalence (P = 0.003) and level of infection donkeys acquired (P = 0.001) in the subsequent dry and short rainy seasons compared to the main rainy season following October deworming. However, these values were not significantly different between the two agro-ecological zones (P > 0.05). This study clearly showed that parasitic infections are primarily acquired during the main rainy season when pasture/herbage coverage is relatively better, and the environment is conducive for parasites survival and development. On the other hand, the finding of majority of donkeys shedding low or no eggs during the dry and short rainy seasons showed that October deworming was effective, and donkeys acquire low or no parasitic infection during the subsequent dry and short rainy seasons. Therefore, the practice of anthelmintic treatment of donkeys at the end of short rain in May may not be necessary, and October deworming once a year is sufficient.

Prevalence of intestinal nematodes in equines with an assessment of the therapy using Albendazole and Doramectin

“…Discrepant results have been reported in other surveys which said that; the working horses' worm egg shedding varies seasonally, with dry weather and short rainy seasons in Ethiopia linked to a lower prevalence than long rainy seasons. [27] Other surveys on grazing horses reported that most egg shedding occurred in summer and spring in the UK and in summer and autumn in the USA this variation between the present nding and the previous ndings could be due to differences in the management systems, sample sizes, deworming strategies, and nutritional status of the animals. [28] In the current study, Strongylus species (87.17%) were the predominant species, followed by Parascaris equorum (30.76%) and Oxyuris equi (12.82%) among gastrointestinal parasites identi ed from fecal samples of working equines.…”

Prevalence of gastrointestinal nematodes, parasite control practices and anthelmintic resistance patterns in a working horse population in Egypt

“…Management practices of working horses in the study area have been previously reported and showed no access to pasture grazing and limited contact between horses, 15 which could explain why most horses were identified with low infection intensity in the current study. Previous studies have reported seasonal variation in worm egg shedding in working equids with dry conditions and short rainy seasons being associated with lower prevalence compared with a long rainy season in Ethiopia 36,37 . Additionally, studies on grazing horses reported that most egg shedding occurred in summer and autumn in the USA 17 or in summer and spring in the UK 38 .…”

“…Previous studies have reported seasonal variation in worm egg shedding in working equids with dry conditions and short rainy seasons being associated with lower prevalence compared with a long rainy season in Ethiopia. 36,37 Additionally, studies on grazing horses reported that most egg shedding occurred in summer and autumn in the USA 17 or in summer and spring in the UK. 38 There might be some element of seasonal effect in the current study, but this cannot be fully elucidated unless a longitudinal study is performed.…”

A controlled study on efficacy and egg reappearance period of Ivermectin in donkeys naturally infected with small strongyles

“…Therefore, improving the donkey health status is important to owners, farmers, and consumers. Small strongyles, also commonly called cyathostomins, are among the most important intestinal parasites of donkeys due to the high prevalence values commonly reported in several countries around the world (Matthee et al, 2000;Bu et al, 2009;Getachew et al, 2010;Matthews et al, 2013;Ismail et al, 2016;Jajere et al, 2016;Dibaba et al, 2017). They include more than 40 species and several genera, they belong to the subfamily Cyathostominae and to the family Strongylidae, and they are found in the cecum and colon of domestic equids.…”