Prevalence of Lungworm Infection of Small Ruminants in and Around Sebeta Town, Central Ethiopia

Research Article

Austin J Vet Sci & Anim Husb. 2023; 10(4): 1126.

Prevalence of Lungworm Infection of Small Ruminants in and Around Sebeta Town, Central Ethiopia

Abubeker Hassan¹; Ebisa Mezgebu²*

¹College of Veterinary Medicine and Agriculture, Addis Ababa University, Bishoftu, Ethiopia

²Animal Health Institute (AHI), Sebeta, Ethiopia

*Corresponding author: Ebisa Mezgebu Animal Health Institute (AHI), Sebeta, PO Box: 04, Ethiopia. Tel: +251 93 232 0809; Fax: +251 11 338 0220 Email: ebisamnaf@gmail.com

Received: June 26, 2023 Accepted: August 03, 2023 Published: August 10, 2023

Abstract

Lungworm infection is one of the common parasitic diseases that affect small ruminants. It causes great economic losses due to decrement in production and productivity gained from these animals. There was limited information related to this disease in these animals in the study area. Therefore, this study was conducted to determine the prevalence and species of lungworms in small ruminants and to assess the possible risk factors associated with lungworm infection. A cross-sectional study was conducted from November 2019 to May 2020 on small ruminants selected by a simple random sampling technique in and around Sebeta town, central Ethiopia. A total of 406 animals (259 sheep and 147 goats) were sampled and examined to determine lungworm infection prevalence and its species identification. The study showed that 13.8% (56/406) of an overall prevalence of lungworm infection was found in the study area. In another way, a higher prevalence was observed in sheep 18.1% (47/259) than in goats 6.1% (9/147) and there was a significant association (X2=11.4, p<0.05) between them. Similarly, 14.7% (37/ 251) and 12.3% (19/155), 15.7% (21/134) and 11.7% (16/137), and 14.2% (35/147) and 13.2% (21/159) prevalence were determined between female and male, young and adult, non-dewormed and dewormed animals respectively, but they were not significantly associated with lungworm infection. However, 17.6% (13/74), 13.5% (28/207), and 12% (15/125) prevalence was calculated among poor, good, and medium body-conditioned animals respectively and the difference was not statistically significant (X2=1.24, p>0.05). Dictyocaulus filaria was the only species of lungworm identified in both sheep and goats. This study revealed that lungworm infection was prevalent and affected the production and productivity of small ruminants in the study area significantly.

Keywords: Infection; Lungworm; Prevalence; Sebeta; Small ruminants

Abbreviations: AAU: Addis Ababa University; AHI: Animal Health Institute; BCS: Body Conditions; CI: Confidence Interval; CSA: Central Statistical Agency; E: East; G: Gram; GIT: Gastrointestinal Tract; Km: Kilometer; M: Meter; MM: Millimeter; N: North; P: Probability; Spp: Species; SPSS: Statistical Package for Social Sciences; X2: Chi- square Test

Introduction

Ethiopia has the largest livestock population in Africa. It has about 61.51 million cattle, 33.02 million sheep, and 38.96 million goats. Of the total sheep population, about 72.86% are females, and about 27.14% are males. Out of the total goats, 72.09% are females and about 27.91% are males. About the age distribution of both the sheep and the goats, the largest portions are in the age group of two years and older (53.65% and 51.8%, in that order). These are followed by the young stock under six months for both sheep and goats, this means about 23.99% and 23.52%, correspondingly. Concerning breed, almost all of the sheep and the goats are indigenous (99.72% and 99.98%, respectively) [1].

The economic gains from these animals remain insignificant when compared to their huge number [2]. The low productivity is a reflection of disease, limited genetic potential, and husbandry standards [3]. Frequently, Sheep and goats are the most numerous domestic livestock in Ethiopia [4].

In Ethiopia, small ruminants as much as providing 33% of meat and 14% of milk consumption, and accounts for about 40% of cash income and 19% of the household meat consumption in sub-Saharan Africa. And also they play a great role in the food supply, as a source of income, foreign currency, and as well as to increase foreign exchange earnings [4]. Moreover, the economic benefits to the farmers generate cash income from the export of live animals, meat, edible organs, skin, and in the central highlands where a mixed crop-livestock production system is practiced [5].

However, productivity is much less when compared with the population size of small ruminants in Ethiopia [6]. The production loss is a direct result of clinical and sub-clinical helminth infection resulting from low productivity due to prevailing disease, as well as, insufficient weight gain, mortality, poor nutrition, and indirect production loss which is associated with general lack of veterinary care [7].

Helminth parasites of ruminants are ubiquitous and prevalent in many tropical and sub-tropical environments of the world providing nearly perfect conditions for their survival and development. However, the clinical signs they cause in infected animals can be less obvious than signs of other livestock diseases. Infections with gastrointestinal and other helminth parasites are among the most neglected areas of veterinary care in many of the developing countries. It has however been established that a high prevalence of the infection with less obvious signs is associated with poor production and unthriftiness [8].

About half of all sheep mortality and morbidity on farms in Ethiopian highlands are caused by pneumonia and endoparasitism including lungworms [9]. These lungworms are widely distributed throughout the world but are particularly common in countries with temperate climates, and the highlands of tropical and subtropical countries, and it is common in Ethiopia [10].

Lungworm infection is called Verminous Bronchitis or Verminous Pneumonia and can be caused by three economically important species of lungworm of sheep and goats namely, Dictyocaulus filaria (D. filaria), Protostrongylus rufescens (P. rufescens), and Muellerius capillaries (M. capillaries) [11]. D. filaria is the major cause of lungworm infection of small ruminants particularly affects the potential productivity of sheep in the areas where it is prevalent [12]. Verminous pneumonia is a chronic and prolonged infection of sheep and goats caused by any of these parasitic nematodes, characterized clinically by respiratory distress and pathologically by bronchitis and bronchopneumonia due to infection of the lower respiratory tract, resulting in bronchitis or pneumonia or both [13].

The distribution of lungworm infection in small ruminants depends on different factors such as altitude, intermediate hosts, the climate of the area, and favorable ecological conditions such as humidity, temperature, rainfall, and marshy area for grazing, sheep, and goat management system [14]. The control of these parasites is, thus, crucial for releasing the potential of domestic ruminant production. For proper control to be instituted, however, the diseases and their dynamics must be known. At the present state of our knowledge of parasitic diseases, it is difficult and even dangerous to lay down rigid rules for their control that apply to all regions. For this reason, a study of the epidemiology of each parasitic disease should be limited to small areas [15]. The incidence of parasitic diseases, including respiratory helminths, varies greatly from place to place depending on the relative importance of many of the factors. So far the study on the prevalence of lungworm infections and associated risk factors of small ruminants were not studied in the study area. Therefore, this study was targeted with the following objectives:

¾To determine the prevalence and species of lungworm infection of small ruminants in and around Sebeta town.

¾To assess the possible risk factors associated with the lungworm infection.

Materials and Methods

Description of Study Area

The study was conducted in and around Sebeta town of Oromia regional state from November 2019 to May 2020. Sebeta town is situated 25 km southwest of Addis Ababa. The town is located between 8°44' 59.99"N latitude and 38°39'59.99"E longitude with an altitude range from 1500-3000 m and the total coverage of the area is 103, 758km. This area has mid-sub- tropical weather and high land temperate type climate accounting for 94% and 6% respectively. Mean annual temperature and rainfall range between 15 to 21oc and 800 to 1199 mm respectively. Agriculture is the main occupation of the population of the area. The agricultural activities are mainly mixed type with cattle rearing and crop production undertaken side by side (Figure 1).