Epidemiology of Epizootic Lymphangitis Among Carthorses in Ethiopia.

Musse G Abdela,Sori Teshale,Hawi Jaleta,Gobena Ameni,Balako Gumi,Aboma Zewde,Mesfin M Gobena

doi:10.3389/fvets.2021.762937

Abstract

Epizootic lymphangitis caused by Histoplasma capsulatum variety farciminosum is a debilitating disease incurring considerable economic losses and affecting the welfare of carthorses. Understanding of its epidemiology is important for devising effective prevention and control measures. A cross-sectional study was conducted on 4,162 carthorses in 17 towns in Ethiopia between October 2018 and June 2019. Clinical and microscopic examinations, fungal culturing, and polymerase chain reaction were used to undertake this study. The overall prevalence of epizootic lymphangitis was 16.67% (95% CI: 15.55–17.84) in carthorses. Epizootic lymphangitis was detected in carthorses found in 16 of the 17 towns included in the study. The highest prevalence was recorded at Kombolcha Town (33.33; 95% CI: 27.54–39.52) whereas the lowest was recorded at Debre Birhan Town (0.00; 95% CI: 0.00–1.27). The results of univariable firth logistic regression analysis showed that the difference between the prevalence of Kombolcha and the prevalences of all the other towns except Holota and Shashemene were statistically significant. Statistically significantly lower prevalence was observed in other towns. Classification of the cases into different clinical forms showed that 87.18, 4.33, and 0.58% were cutaneous, ocular, and respiratory forms respectively, while the remaining 7.93% (55/694; 95% CI: 6.03–10.19) were classified as mixed form. In terms of the severity of the disease, 28.67, 60.52, and 0.81% were mild, moderate, and severe cases, respectively. The majority of the lesions (43.95%) were observed in the skin followed by forelimbs (14.55%) and neck region (14.27%). Higher mean annual temperature, lower annual rainfall, and higher humidity of the study towns were statistically significantly associated with an increased risk of epizootic lymphangitis. In conclusion this study revealed widespread occurrence of epizootic lymphangitis in carthorses yet a heterogeneous prevalence between towns. The veterinary and livestock authorities should take this into account while devising disease control.

Highlights

In Ethiopia, horses provide a multitude of services to both rural and urban communities, which are crucial for their livelihood
Epizootic lymphangitis was detected in carthorses found in 16 of the 17 towns included in the study
Their welfare and optimum service is hampered by diseases such as epizootic lymphangitis

Summary

Introduction

In Ethiopia, horses provide a multitude of services to both rural and urban communities, which are crucial for their livelihood. In certain parts horses provide draft power for preparation of croplands [1, 2]. Despite their immense services, horses often suffer from a number of infectious diseases having considerable impacts on their welfare and livelihood of their owners. Epizootic lymphangitis is one of the infectious diseases posing huge socioeconomic and welfare concerns on horses, specially carthorses. It is a contagious, chronic, debilitating disease caused by a thermally dimorphic fungus Histoplasma capsulatum variety farciminosum which occurs as a yeast form in host tissues and as a mycelial saprophytic form in the environment [3]

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Results

Conclusion