Fasciola hepatica which are commonly known as the liver flukes of sheep, goat and cattle, are parasitic flat worm of the class trematoda, phylum platyheminthes that infects the livers of various mammals including humans. The disease causes by the flukes called fascioliosis, [1]. Fasciola hepatica is distributed worldwide, and cause great economic losses in sheep, cattle and goats, and has been known as an important parasite of sheep, cattle and goat for hundreds years back. Because of its size and economic importance, it has been the subject of many scientific investigations and has been the best knowing of any trematode species, [2]. It inhabitants the bile duct of sheep, cattle, goats and some other ruminant animals. It has a length of 30mm long and 13mm width. Lynaea truncatula is the secondary host or intermediate host for fasciola hepatica, in which some of its larva stage are multiplies and constitute a serious hazard to the animal especially in a region where the condition exist for the survival and multiplication of the intermediate host (snail) [3].

Fasciola hepatica is found to survive within the intermediate host and also in wet marshy pasture, area subjected to flooding or badly drained upland. Sheep, goat, cattle and other ruminant animals during grazing are capable of ingesting the infective larva stage of the flukes which is likely to Cause the diseases known as fascioliosis [3]. 

The snail lymnaea is the intermediate host of the Fasciola hepatica, the snail lymnaea is generally small, and there are many species to be found in the tropics. Lymnaea truncatula may be taken as the characteristic, of the group. The shell of the snail is about 8-12 mm long, brown white in color having 5-6 spiral coils, the width having about half of the length it does not possess operculum, it is amphibious and therefore feed on the smaller living organism in water, [4]. The snail prefers water which is not flowing faster and adjusting itself to the area between deep water and dry land. It can survive for quite a long period under comparatively dry condition provided it is protected from direct sun light [5].

Pathology of Fasciola hepatica

When a goat, sheep, cattle or any ruminant animal are infected with the liver flukes, the liver become seriously affected in structure and in infection. The animal is said to be suffering from liver rot, it’s become dropsical and there is a great muscular weakness. It is therefore of great importance that such a serious diseases should be kept well in checks, and this could only be done effectively if the life cycle of the parasite was taken into account, [3].

Symptoms of the Disease 

The physical symptoms of the liver flukes infection is observed some month later and is manifested in goats, sheep, cattle and some other ruminant animals by progressive anemia and loss of condition wool and edematous swelling of eyelid, throat and at times pendulous condition of abdomen. The animal become weaker and the disease terminate in extreme emaciation and death, [6].

Prevention and Control of fascioliasis

There are several possible methods of preventing the disease from spreading. The parasite may be attacked directly in its larval stage, and this can be done by destruction of the secondary host snail (Limnaea species).It can be done in various ways, either by introduction of the natural enemy (predator) to the pasture so that they can feed on the snail to reduce their population or by draining the pasture. This method is usually adopted because of it efficiency, [7].

According to Hall [8] adequate disposal of cattle faces and regular checking of the grazing land to ensure that there is no snail existing within or avoid cattle from grazing in the area were snail are available. Adequate use of drugs of choice that is Triclabendazole which is originally develop as a veterinary drugs and is now registered in several countries and is recognized and recommended by world health organization (WHO), will also reduce the infection of the disease.

Treatment

In the 1920 numerous compound have been investigated for efficacy against Fasciola hepatica in sheep since it has been provide efficacious as having carbon tetrachloride (CCl4).Carbon Tetrachloride (ccl4) was the first truly effective remedy to be introduced for the treatment of Fascioliasis. Its effectiveness against gastro intestinal nematode was recognized by (subsequently, veterinary researchers in both Germany and north Wales was found it to be effective against Fasciola hepatica in sheep conversely, [5]. Other useful molluscides are copper Sulphate, Sodium Penta Chlorophenate and Calcium Cynamid, [9]. Also a recently developed Tritymorpoholine, in now preferred to the others, it is more selective and cheaper, and it gives 90% kills of the intermediate host (snail), it is not toxic to the grazing animal, less toxic to the adequate living and very easy to apply, [10] (Figure 1). 

Figure 1: The Life Cycle of Fasciala Hepatic

Figure 2: A Map showing Gashua town, Bade Local Government, Yobe State

Epidemology

Infection begins when matecercariae, infected aquatic vegetation are eaten or when water containing metacecariae are drunk by animal. Human often infected by eating water cress, [2]. Human infection normally occurs in some part of Europe, North Africa, Cuba, South America and other locales. Fasciala hepatica is one of the most importance diseases of domestic animal throughout the world, [11].

The following materials were used to carry out the investigation of incidence or prevalence of Fasciola hepatica in slaughtered livestock or animal in Gashua Abattoir (Figure 2).

Preparation of Normal Saline

0.85g of common salt (Sodium Chloride NACL2) was weighed using weighing balance and dissolves in 100ml of clean warm water; it was then allowed to stand for 5 minutes then filtered solution using filter paper, Soulsby [12].

Equation for the reaction: 

Study Design

A cross sectional study type was conducted to determine the prevalence of Fasciola hepatica by using direct saline technique examination, different organs were examined but a special attention was given to the livers of the slaughtered livestock. The liver of each slaughtered animal was carefully examined by visualization and palpation of the entire organs that was followed by traverse incision of the organ across the thin leaf lob in order to confirm the incidence [13] a total of 200 animals were used for both Feacal and fresh liver samples. Fresh portions of liver from livestock were bought and Feacal sample were directly collected from the rectum of the slaughtered animal by using of disposable hand glove. The samples were collected in respective of breed, age and sex.

Examination of the Liver Sample

A cleared sterilized container was placed on the table, then some portion of the fresh liver was put into the container containing normal saline in other to dehydrate the water content in the liver, it was the cut open with a sharp sample knife to expose the fluke, Then a hand lens was used to observed the infected organs for easy identification of the fluke [13].

Microscopic Examination of the Feacal Sample 

The Feacal sample was examined for gastro intestinal parasite by using direct saline method. A clean grease free slide is

placed on a flat table, 2-3 drops of normal saline was added on to the slide, and the Feacal sample was applied on the slide and stirred thoroughly using application stick. It then placed on the microscope stage for Examination; it was examined using x10 and x100 objectives lens for final identification, [14].

The Table below shows a total number of 200 Animals which were examined during the period of this research work. 66 goats, 68 sheep and 66 cattle. The study was carried out between the periods of two consecutive months July-August 2013 (Table 1-3).

Percentage rate of infected = No of infected x 100

                                                                                                                                                               No of examine

Average percentage rate incident = Total no of infected x 100

Total no of examined = 20x 100 = 30

                                                                                                                                                                            66

Therefore the percentage incident of goat infected with Fasciola hepatica is 30%.

Percentage rate of infected = No of infected x 100

                                                                                                                                                             No of examine

Table 1: The Distribution of Animals Studied During Sampling Days between Days D1-D9

Table 2: Shows the Distribution of the Incidence of Fasciola Hepatica among Goat Species during Days of Sampling

Table 3: The Number of Incidence of Fasciola Hepatica among Sheep

Table 4: The Incidence of Fasciola Hepatica among Cattle Slaughtered In Gashua Abattoir

Table 5: The Table Below Shows the Overall Incidence of Fasciola Hepatica among the Slaughtered Animal in Gashua Abattoir

Figure 3: Graphical Presentation of Result

The graph above showing the percentage rate incidence of Fasciola hepatica among goats, sheep and cattle’s slaughtered in Gashua abattoir from July-August 2013

Average percentage rate incident = Total no of infected x 100

Total no of examined = 34 x 100 =50

68

Therefore the percentage incident of sheep infected with Fasciola hepatica is 50%.

Percentage rate of infected = No of infected x 100

No of examine

Average percentage rate incident = Total no of infected x 100

Total no of examined = 29x 100 =44

66

Therefore the percentage incident of sheep infected with Fasciola hepatica is 44% (Table 4-5 and Figure 3).

Fascioliasis has been a great problem of development especially in developing countries of the tropic region. Despite all the tremendous efforts by government and non-governmental agencies in the control of Fasciola, yet the disease is far from control in some part of the world especially where water bodies are abundant, and Gashua is not left out. The result of this research work, reveal that between July and August 2013, a total number of 200 animals were examined which make up 66 goats, 68 sheep and 66 cattle were sample from Gashua abattoir, out of this figure, 20 goats were found to be infected by Fasciola hepatica, 35 goats non infected and 11 goats are found to be condemned or undefined samples, therefore the average rate of infection in goats was found to be 30%. While in sheep 68 samples were examined, 34 sheep was found to be infected and 27 non infected and 7 samples were found to be condemned/undefined, an average rate of 50% was found to be infected. For cattle 66 numbers of cattle samples were examined of which 29 samples were found infected and 30 non infected and 7 samples were found to be condemned or undefined, with percentage rate infection 45%.Therefore the result of this research work further reveals that the sheep are appear to be more susceptible to the Fasciola hepatica than cattle and goats in this area. This finding was contrary to the report of [13], which was reported as higher percentage incidence of Fascioliasis in cattle than in sheep and goat.

The results of this project reveal that, the infection of Fasciola hepatica is prevalence in the study area. And the infection is higher in sheep than cattle and goats in the study area. The prevalence is relatively high throughout the year, probably the area is suitable for the development of the intermediate host snails which are responsible for the transmission of the disease. 

The infection among livestock (that is, cattle, goats and sheep) causes great economic loss as a result of condemnations of the infected livers.

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