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Article 

Prevalence of bovine schistosomosis in fogera district 
Kindalem Bayew Wassie* 

Animal Health Department Head in Janamora Wereda Livestock Development Office. Janamora, North Gondar, Ethiopia 

Correspondence: kindalembayew@gmail.com 
. 

 

Abstract: A cross-sectional study was conducted from February 2019 to April 2020 in Fogera district to determine the prevalence of 

bovine Schistosomosis. Schistosomosis in cattle is one of the well known parasitic diseases locally referred to as ‘’Yeweha till’’ meaning 

water-borne worm infection. From the total of 430 cattle examined using coproscopical examination in the field survey 27.9% (n= 

120) were found to be positive for schistosoma bovis. Of the total 80 cattle examined in the abattoir, 12.5% (n=10) were positive for 

shistosoma adult female and male worms during postmortem finding but only 6.25% (n=5) of them were found positive schistosoma 

eggs using coproscopical examination. The prevalence of schistosomosis was found also higher in local cattle (23.49%) than that of 

Fogera (6.04%) and cross-bred cattle (Local X Fogera) (4.42%). The prevalence of the disease was higher in age group of cattle above 

5 years of age (15.8%) than that of age groups between 1.5 to 5 years (10%) and below 1.5 years (2.09%). The prevalence of bovine 

Schistosomosis in female cattle (14.90 %) was found greater than that of male (13.02%). The present study was carried out on bovine 

schistosomosis in Fogera district has the objectives of to provide detailed information of cattle Schistosomosis, to determine the 

prevalence of bovine schistosomosis according to sex, age and breed of cattle and to determine the prevalence of bovine schistoso-

mosis in slaughtered animals. 

 

Keywords: Prevalence, Schistosoma bovis, Fogera, Ethiopia  
 

1. Introduction 
 

Schistosomosis (blood fluke disease or bilharzosis) is an infection due to the genus 
schistsoma.  

Although this parasite occur in many tropical and subtropical areas, the disease is 
important in livestock mainly in Easter Asia, Africa and India [1, 2]. Adult Schistosomes 
are obligate parasite of the blood vascular system of vertebrates. Schistosomes are dioe-
cious (unisexual) worms, which is an exception among the trematodes [3, 4]. 

Visceral Schistosomes mature in the hepatic portal veins, mate and migrate to the 
mesenteric veins where egg production starts [3]. The female in the mesenteric vein insert 
her tail in to the venule. The eggs penetrate the venule endothelium aided by their spines 
and by proteolytic enzymes secreted by the unhatched miracidia [5, 7]. Egg lay by the 
female worm penetrate the wall of the veins and migrate to the intestinal lumen or the 
nasal cavity. (S.nasale) of the host are retained inside the body and it is the retained eggs 
and their products that responsible for most morbidity from Schistosomosis [8]. 

 

Received: 27.10.2023 

Accepted: 27.11.2023 

Published: 30.12.2023 

DOI: 10.52331/cvj.v28i3.55 

 

 

 

Copyright: © 2021 by the authors. 

Submitted for possible open access 

publication under the terms and con-

ditions of the Creative Commons At-

tribution (CC BY) license (http://crea-

tivecommons.org/licenses/by/4.0/). 

mailto:kindalembayew@gmail.com


Cluj Vet J 2023, vol 28, issue 3 10 of 30 
 

In addition to the high prevalence rate and outbreak of the disease, it has an economic impact like 
production losses due to S.bovis result from mortality, delayed growth, partial liver condemnation and poor 
future reproduction performance and sub clinical infections cause significant losses due to long term effects 
on animal growth and productive capacity or milk yield, draft power and increase susceptibility to other 
parasitic or bacterial disease [9, 10]. In humans’ economic losses in terms of working hours has been shown 
[11]. 

A form of cutanous larva migrants often called “swimmers itch” (cercarial dermatitis) occurs in man 
and Schistosomes which have a limited migration in human skin [7, 12]. Migratory water fowl frequently 
harber schistosomes (blood flukes) in their blood vasculature. These schistosomes produce eggs that pass in 
the bird’s feces to the water environment. The eggs hatch, producing miracidia, which turn penetrate a 
aquatic snails with the snail, the miracidium undergo asexual reproduction and produce thousands of cer-
cariae these cercariae exit the snail hope fully to penetrate the definitive host, the migratory water fowl [6, 12]. 
Humans serve as incidental hosts for these avian schistosomes. During the swimmer months, people swim 
or wade in the lakes, ponds, rivers and even ocean waters frequented by the wild birds.  

In Ethiopia, reports on animal schistosomes are very scanty and until recently it has been considered 
as an occasional finding in slaughter house and postmortem examinations [13]. It has been reported that 
S.bovis is the only species reported with localized distribution in ten out of fourteen administrative regions in 
the country [14, 15]. Detailed information on prevalence and intensity of infection of S.bovis in Ethiopia and 
various factors, which influence the host parasite relationship, are generally lacking. The present study was 
carried out on bovine schistosomosis in Fogera district with the following objectives; 

• To provide detailed information of cattle Schistosomosis. 

• To determine the prevalence of bovine schistosomosis according to sex, age and breed of cattle.  

• To determine the prevalence of bovine schistosomosis in slaughtered animals in abattoirs. 

2. Materials and methods 

2.1 The Study Area 

The study was conducted from February 2019 to April 2020 in Fogera area. The study area is located 
1800 to 2000 m a.s.l with elevation of the area is feature predominantly moderate Woynadega temperate high 
land Dega climates.  The land scope is marked by the present of Lake Tana in adjacent side which drains of 
water shed about 3000km2 and surrounded by High Mountain with plains slopping patches of land near the 
shore line. The area has a summer rain fall with mean annual rain fall and mean annual temperature of 1600 
mm and 200C respectively.  

The rich agricultural land of the area supports a large livestock population, water and grazing pastures 
being abundant for months of the year, but due to periodical flooding during rainy season, cattle have to 
move to the hill side. 

2.2 Animals and management 

The dominant cattle breed in this region is local indigenous Fogera cattle. In the study area both tra-
ditional and modern (semi-intensive) livestock farming are practiced. In the traditional management system 
animals are often kept out-doors and grazed all day near the vicinity of the Lake Tana. These grazing areas 



Cluj Vet J 2023, vol 28, issue 3 11 of 30 
 

are potential sources of schistosome infection due to the frequent contact of animals to the water bodies. In 
the semi-intensive management system, cattle are kept in-doors and partly out-door. While indoors, they are 
supplemented with adequate qualities of feed and clean water. Their management of outdoors is similar to 
the traditional extensive farming type. 

2.3 Study population 

The sampling units of the study were local and cross breed cattle. A total of 430 cattle were considered 
in this study for coproscopical examination and were registered according to their breed, sex and age. The 
age of the study animals was determined by dental eruption formula which involves counting number of 
permanent incisors [3, 6, 16]. The group of age of animals are Group I:0≤X< 1.5 years, Group II: 1.5≤X ≤5 years 
and Group III >5 years. 

2.4 Study Design  

A cross sectional study was conducted to determine the prevalence of bovine Schistosomosis. The de-
sired sample size was calculated using the formula given by Thrusfied [17]. 263 cattle were selected using 
random systematic sampling method to estimated prevalence of the disease. However, due to low number of 
positive animals at the beginning of the study, the sample size was increased to 430 cattle. 

2.5 Study Methodology  

2.5.1 Coproscopical Examination 

The purpose of coproscopical examination was to determine the presence or absence of schistosoma 
egg in the feces. Fresh fecal samples were directly collected form rectum of 516 animals and preserved with 
10% formalin in a universal bottle to prevent hatching of miracidia then after sedimentation procedure was 
done till the sediment of the fecal sample become clear. Following these all procedures the prepared sample 
observed under low power microscope in the laboratory [18]. 

2.5.2 Post -mortem Examination 

The fecal sample were collected during antemortem examination with universal bottles and labeled to 
examine the same animals during post mortem time. At post mortem examination the liver, portal vein, mes-
enteric vein where observed and incised to find the adult schistosomes and also the whole root of intestine 
were examined superficially to appreciate the presence of lesions and dead parasites at the junction of the tip 
of the vein  and the wall, serosa and subserosa of the intestine [7]. 

2.6. Statistical Analysis  

The sample size of the field survey were classified in to three parameters breed, sex, and age then the 
data was managed by using SPSS (17 version ) program and the prevalence between the parameters was 
analyzed using chi-square (χ2) test and binary logistic analysis. While the comparison between post mortem 
finding and fecal examination was handled by using simple prevalence rate. 



Cluj Vet J 2023, vol 28, issue 3 12 of 30 
 

3. Results 

3.1. Overall Prevalence 

From the total of 430 cattle examined using coproscopical examination in the field survey 27.9% (n= 
120) were found to be positive for schistosoma bovis. Of the total 80 cattle examined in the abattoir, 12.5% (n=10) 
were positive for shistosoma adult female and male worms during postmortem finding but only 6.25% (n=5) 
of them were found positive schistosoma eggs using coproscopical examination.  

Table 1 Infection prevalence of bovine Schistosomosis in different breeds, sex and age groups 

of Fogera district. 

  

The prevalence of schistosomosis was found also higher in local cattle (23.49%) than that of Fogera 
(6.04%) and cross-bred cattle (Local X Fogera) (4.42%). The prevalence of the disease was higher in age group 
of cattle above 5 years of age (15.8%) than that of age groups between 1.5 to 5 years (10%) and below 1.5 years 
(2.09%). The prevalence of bovine Schistosomosis in female cattle (14.90 %) was found greater than that of 
male (13.02%).was found greater than that of male (13.02%).  

3.2. Abattoir survey 

From the total of 80 male cattle slaughtered at Wereta Municipal Abattoir, the purpose of this survey 
was to compare the prevalence difference between post mortem finding and coproscopic examination. Dur-
ing post mortem Schistosoma bovis was found in the mesenteric, portal veins were examined and incised. 12.5% 
(n= 10) were found to be positive but only 6.25% (n= 5) of the 80 cattle were positive in coproscopic examina-
tion. 

4. Discussion 
Schistosomosis in cattle is one of the well known parasitic diseases locally referred to as ‘’Yeweha till’’ 

meaning water-borne worm infection. As well as most of the slaughtering practice took place in backyard 
slaughtering system so that the dumping of the stomach and intestinal contents, including the blood and 

Animals 

 

 

Total number of 

Animals examined 

 

Number of 

positive 

Animals 

 

Preva-

lence (%) 

Breed Local 211 75 17.44 

Fogera 145 26 6.04 

Cross 74 19 4.42 

Age 

group 

I 52 9 2.09 

II 154 43 10 

III 224 68 15.8 

Sex Male 182 56 13.02 

Female 248 64 14.9 

Total  430 120 27.9 



Cluj Vet J 2023, vol 28, issue 3 13 of 30 
 

washed material nearby water bodies (rivers, irrigation canals, ponds e.t.c) can create an easy access to the 
snail intermediate to the egg of schistosoma from such materials. This practice together with contamination 
of water bodies with manure and defecates, as in case in some areas where there is poor watering facilities, 
could highly contribute to the spread of the disease in surrounding at large, in addition to the above problem 
the koladiba municipal abattoir itself has got hygienic problem that will contribute for the occurrence of the 
disease. 

The overall prevalence of S .bovis infection 27.9% in the study area was found lower than the previous 
studies in which prevalence rate around Bahir Dar were 33.8% [19] and 34% [20]. The lower prevalence of 
schistosomosis recorded in this study may be due to the fact that trematodes are intermittent egg layers so 
that the chance of detecting eggs by fecal examination may be minimal. In addition to this not all schistosoma 
eggs are excreted in the faeces, many of them may be trapped tissue [21]. Moreover, the number of adult 
parasite established in the mesenteric veins and the stages of infection may determine fecal egg output thus, 
postmortem examination is more specific to detected schistosoma infection than coproscopical examination.  

The prevalence of Bovine Schistosomosis was found higher in local cattle (17.44%) that of Fogera (6.04%) 
and cross-bred cattle (Local X Fogera) (4.42%). This finding is not in line with other reports in which the 
prevalence of bovine schistosomosis higher in crosses cattle than local cattle [15, 20]. The reason for this dif-
ference in prevalence rate between breeds may be due to the cross breeds are mostly indoored for fatting or 
dairy purpose by supplementing good feed and clean water so that they cannot get access to the miracidium; 
while the local once are mostly released extensively to graze freely and then they will get acquired immunity 
through long time exposure the above statement also related with research paper that was done in Sudan 
which suggests that Sudanese cattle were apparently acquired immunity to S. bovis as a result of repeated 
exposure [22]. 

The prevalence of schistosomosis in this study which was higher in age group of cattle greater than 5 
years than that of 1.5 to 5 years and below 1.5 years of age. This finding is not in line with other reports [15, 
20] around Bahir Dar .The lower prevalence (2.09%) in age group I cattle may be due to the fact that most 
calves are kept indoors hence have low chance to cercariae exposure. 

The higher prevalence of schistosomosis in this study in female cattle than male cattle is not in line 
with the previous study [15] in Bahir Dar .The reason for the higher prevalence in female than that of male in 
cattle is that cows were in stress of lactation and pregnancy even though the two sexes are equally exposed 
to the disease because they graze at the same time in the same place [23]. 

 In the postmortem examination of slaughtered animals to determine the adult Schistosome worms 
from portal veins were examined and incised. 12.5% (n= 10) were found to be positive but only 6.25% (n= 5) 
of the 80 cattle were positive in coproscopic examination. The reason for this difference in prevalence of schis-
tosomosis between abattoir survey and coproscopical examination may be due the fact that trematodes are 
intermittent egg layers which are dependent on the age of animal [3]. 

5. Conclusion and recommendations 
Bovine Schistosomosis is one of the endemic disease condition in the study area that deserve serious 

attention in the future even though there has been little recognition of its veterinary significance, cattle Schis-
tosomosis does cause significant loss through out the world. This is due to the nature of the disease, which 
usually occurs at sub clinical level with long term effect on animal growth and productivity and increase 
susceptibility to other parasitic or bacterial diseases. It is, therefore, important to obtain more information on 
natural schistosomes’ infection in cattle in general, and on the evaluation of the host–parasite relationship 



Cluj Vet J 2023, vol 28, issue 3 14 of 30 
 

under condition of challenge in particular. Despite the fact that there was no significant difference between 
male and female cattle, it should be allowed to graze the cattle at the same time and the same place to avoid 
transmission in between because females give a high economic value as compared to males. 

Based on this study, the following recommendations are forwarded. 
 Schistosomosis should be taken in to consideration as a one of the major limiting factor to 

livestock productivity in Fogera District; hence any Endeavour towards animal disease control strategy must 
include it in the priority list. 

 Further detailed studies are needed to gather a rich database both on the parasite and its vector, 
which will be useful to envisage a cost effective and sound Schistosomosis control measure in the area. 

 Farmers should get educated about the transmission of the disease at least to tell them not to let 
their cattle freely in swampy area and supply dry feeds sometimes. 

 Cross breeds should be kept indoors and supplying of clean water should be performed to 
prevent infection as they are highly sensitive to the disease. And also different ages and breed groups should 
not graze together. 

 Available means in snail control and disease monitoring could be implemented as a short term 
activity. Indigenous knowledge deserves investigation in this regard. The native Ethiopian plant 
phytoplancca dodecandora, locally known as Endod which is considered as potent molluscicide for the 
control of human Schistosomosis, could also be effectively used against intermediate host of S. bovis. 

 

6. References 
1. Hall, H.T.B. Disease and parasites of livestock in the tropics, 2th ed.; Longman group Ltd. London, 1985; 213-214. 

2. Sewell, M.M.H.; Brocklebsy, D.W. Handbook on Animal Diseases in Tropics, 4th ed. Bailliere Tindal, London, 1990; Pp.132-135.  

3. Bont, J.D.; Cattle Schistosomosis: host parasite interactions. 1995, University of Gent, 23. 

4. Reinecke, R. K. Phylum plathelminthes veterinary helminthology, buttheresorths. Pretoria, 1989; 245-248; 265-273. 

5. Brown, D.S. Fresh water snails of Africa and their medical important, London, Taylor and fransis, 1980; p. 482. 

6. Aiello, S. E. and Mays, A. The Merck Veterinary Manual, 8th edi, Merck and co., Inc., Whitehouse Station, N.J., U.S.A. 1998; P. 

29 -31. 

7. Urquhart, G.M., Armour, J., Duncan, J.L. and Jennings, F.W. Veterinary helminthology: Veterinary Parasitology. Churchill 

Livingstone Inc. New York. 1987; P. 114-116.  

8. Fekade, D., Woldemichael, T.A, and Tadele, S. pathogenesis and pathology of Schistosomosis, 5th ed. Addis Ababa 
University printing Press, Addis Ababa. 1989; p. 34. 

9. Dargie, J. D. The pathogenesis of schistosoma bovis in Suddanese cattle. Trance. Roy. 1980; P. 560-562. 
10. Chandiwana, S. K., Taylor, P. and Makuria, O. Prevalence and distribution of schistosoma. Soc. Bel. Med. Trop. 

1978; P. 167-172. 
11. Aemro, T. Assessment of prevalence, economic significance and drug efficacy trial on bovine Schistosomosis in 

Bahir Dar, Ethiopia. DVM Thesis, faculty of veterinary medicine, Addis Ababa University, Debre Zeit, Ethiopia. 
1993; p. 35. 

12. Hendrix, M.C., Robinson, D.E. Diagnostic Parasitology for Veterinary Technicians, 3rd ed., New York. 2006; p. 152. 
13. Shibru, T., Getachew, T. and Hailu, B. Schistosomosis in Ethiopia. AAU. Addis Ababa. 1989; P. 18 - 26. 
14. Graber, M. Helmith and Helmithiasis of domestic and wild animals in Ethiopia. Vol.1. AAU. 1975; p.101. 



Cluj Vet J 2023, vol 28, issue 3 15 of 30 
 

15. Solomon, O. Observations on the prevalence of schistosoma bovis infection in Bahir Dar area, north central Ethiopia. 
Faculty of Veterinary medicine, Mekele University, Ethiopia. 2008; p. 35. 

16. Frandson, R.D. Anatomy and physiology of farm animals, lea and febiger Philadelphia. 1992; Pp. 306-308. 
17. Thrusfied, M. Veterinary epidemiology. 2nd ed. UK, Blackwell science. 1995; p. 182-189. 
18. MAFF (Ministry of agriculture fisheries and food). Manual of Veterinary Parasitology Laboratory Technique, 

Technical Bulletin No. 18, p 3-4. 
19. Haile, A. Observations on the prevalence of schistosoma bovis infection in Bahir Dar area, North central Ethiopia. 

Faculty of Veterinary medicine, Mekele University, Ethiopia. 1985; p.42. 
20. Hailu, M. Observations on the prevalence and intensity of schistosoma bovis infection in Bahir Dar area, North 

central Ethiopia. Faculty of Veterinary Medicine, Addis Ababa University, Debre Zeit, Ethiopia. 1999; p.52. 
21. Yalelet, W. Survey on Bovine Schistosomosis in and around Bahir Dar, northwestern Ethiopia. Faculty of 

Veterinary Medicine, Addis Ababa, Debre Zeit, Ethiopia. 2004; p. 26. 
22. Craig, T.M. Epidemiology of internal parasites, Effects of Climate and Host on reproductive cycles on parasite 

survival. Ruminant for the mixed animal paractioner; Western Veterinary conference, Las Vegas, Nevada. 1998; 
p.4-5. 

23. Taylor, M.G. Schistosomosis of domestic animals: Schistosoma bovis and other animal forms in immune responses 
in parasitic infections. C.R.C. press, Boca, Rauton. 1987; p. 49. 

 


