Cyst Viability, Organ Distribution and Financial Losses due to Hydatidosis in Cattle Slaughtered At Dessie Municipal Abattoir, North-eastern Ethiopia

A cross sectional study was conducted from October 2010 to March 2011 to assess the prevalence, cyst viability, organ distribution and financial losses of bovine hydatidosis in cattle slaughtered at Dessie municipal abattoir. Postmortem inspection, cyst characterization and financial loss estimations were conducted. Out of 610 inspected cattle, 83 (13.61%) were harbouring a single or multiple hydatid cysts. Significantly (P 0.05) was not observed in different age groups. Anatomically, the cysts were distributed 68.67% in the lung, 14.46% in the liver, 6.02% in the kidneys, 1.2% in the heart and 9.64% were found both in the lung and liver. Of the total examined cysts (195) for fertility and viability, 27 (13.85%) were fertile, 44 (22.56%) were calcified, 124 (63.59%) were sterile. The rate of cyst calcification was higher in the liver (78.14%) than other organs whilst the fertility percentage was higher in the lung (14.65%). Of the total 27 fertile cysts subjected to viability test, 13 (6.67%) were viable. Size assessment made on 195 cysts indicated that 153 (78.46%) were small, 41 (21.03%) were medium and one (0.51%) were large sized cysts. In the present study, the total annual economic loss from organ condemnation and carcass weight loss due to hydatidosis was estimated as 681,333.87 Ethiopian birr which is about 39157.12 United States dollar per annum based on the local market prices in the study period. The result of this study revealed that hydatidosis is an economically important disease of cattle which necessitates designing of appropriate strategies for its control.


Introduction
The adult parasite produces eggs that come with faeces and contaminate the pasture.The intermediate hosts, Hydatidosis, caused by the larval stages of a tiny commonly herbivores ingest the egg while grazing and tapeworm Echinococcus granulosus, is a serious then hydatid cysts develop in their body.Human problem for both livestock and public health in many beings suffer from the disease if exposed to the egg part of the world.In livestock industry, it inflicts accidentally or consumed with contaminated green enormous economic losses due to condemnation of food or water (Hendrix and Robinson, 2006).The edible organs and lowering the quality and quantity of definitive host is infected by ingestion of infected meat, milk and wool production (Craig et al., 2007; offals of herbivores.The infection rate to dogs is Fromsa and Jobre, 2011).In human, the cyst can reside directly proportional to the fertility of cysts (Urquhart and grow in liver, lung and other visceral organs.The et al., 2003).So cyst characterization is important to pathogenecity of hydatidosis depends on the extent assess the infectivity of the parasite.and severity of infection and the organ on which it is Hydatidosis is one of the major causes of organ condemnation in most Ethiopian abattoirs and situated.Occasional rupture of hydatid cysts often a,b,c leads to sudden death due to anaphylaxis, haemorrhage slaughter houses (Kebede et al., 2009 ;Tolosa et al., 2009;Getaw et al., 2010;Fromsa and Jobre, 2011) and and metastasis (White et al., 2004;Getaw et al., 2010).leads to huge economic losses.Human cases of The parasite spends most of its adult life in the hydatidosis are frequently reported from different intestine of the definitive host, particularly in dogs.corner of the country (Biluts et al., 2006;Kebede et al., and Habel, 1989) as animals less than three years old d were not slaughtered during the study period.Simple 2009 ) and the disease is much more common in the rural areas of Ethiopia where dogs and domestic random sampling was followed to select animals for animals live in a very close association (Fromsa and sampling in the abattoir.Jobre, 2011).Despite these, the status of hydatidosis in Study design and Methodology: A cross sectional livestock and the economic impact of the parasite were study on cattle hydatidosis was conducted at Dessie not studied so far in and around Dessie.Therefore, the municipal abattoir.Postmortem inspection, cyst objectives of this study were to determine the characterization and financial loss estimation were prevalence, cyst viability and organ distribution of carried out.bovine hydatidosis and to estimate the financial losses due to the disease in the area.The study animals were local zebu as high (volume >20ml), medium (volume between 6cattle (Bos indicus) brought to the abattoir for 20ml) and low (volume <6ml).The collected cysts slaughter from districts around the town (Tewuledere, were carefully incised and examined for protoscolices, Tenta, Dessie Zuria and Kutaber).All slaughtered which looks like white dots on the germinal animals were male.Extensive system is dominant epithelium, in hydatid fluid so as to classify cysts as husbandry practice in the area in which animals are fertile or infertile.The infertile cysts were further allowed to graze freely and housed in poorly classified as sterile (fluid filled cysts without any a constructed barn at night.protoscolices) or calcified (Kebede et al., 2009 ).Fertile cysts were further subjected to viability test.A Sample size and Sampling Methods: The total segment containing protoscolices was placed on the number of cattle required for sampling was calculated microscope glass slide and covers with cover slip and based on the formula given by Thrusfield (2005).
observed for amoeboid like peristaltic movement with Since there was no information about the prevalence (40x) objective.For clear vision, a drop of 0.1% of the disease in the area, 50% prevalence was taken to aqueous eosin solution was added to equal volume of calculate the sample size with 5% absolute precision.
protoscolices in hydatid fluid on microscope slide So the calculated sample size was 384 cattle however, with the principle that viable protoscolices should to increase the accuracy, the sample was increased to completely or partially exclude the dye while the dead 610.During ante-mortem inspection, each animal was ones take it up (Dalimi et al., 2002).given an identification number.The age, sex and body condition of each individual animal was assessed and Economic loss assessment: An attempt was made recorded.Based on the body condition, animals were to estimate the annual economic losses from grouped as poor, medium and good (Nicolson and hydatidosis in cattle taking into account losses from Butterowrth, 1986).Animal's age was categorized into cost of organ condemnation and from carcass weight.adult (3 to 5 years) and old (>5 years) based on the The retail market price of average size offal (lung, owners information and dental eruption (De Lahunta liver, kidney, heart and spleen) and the cost of one kg cattle (83) harbouring hydatid cyst, 75 (%) were involving a single organ whereas the remaining 8 (%) Data analysis: Data were collected and recorded in had multiple organ involvement.A maximum of 20 Microsoft excel spread sheet and the prevalence of cysts were encountered from a single lung of cattle and hydatid cyst was calculated by dividing the number of totally 195 cysts were counted and evaluated.Of these hydatid positive animals with the total number of cysts, 27 (13.85%)were fertile and contained animals examined.The associations of risk factors protoscolices whereas the remaining 124 (63.6%) and with the disease were assessed using Pearson's chi 44 (22.6%) were sterile and calcified cysts, respectively.square.All statistical analyses were done using SPSS Of the fertile cysts (27), 13 (6.7%)were viable while version 17 (SPSS, 2008).Probability (P) value less than 0.05 was set as statistically significant in all cases.14 (7.18%) were non-viable.More fertile (14.65%) and sterile (73.25%) cysts were observed in lungs.The Result rate of cyst calcification was higher in the liver Prevalence of hydatidosis: Of the total 610 animals (78.14%) than in the other organs (Table 3).inspected, 83 (13.61%) animals were positive for Cyst size and volume: Out of the 195 recorded bovine hydatidosis.The infection rate was 22.89% in hydatid cysts, 153 (78.46%) were small, 41 (21.03%) poor, 12.99% in medium and 10.40% in good medium and one (0.51%) large in size while 62 conditioned animals.The prevalence was statistically (31.79%) were low, 72 (36.92%) medium and 7 significant (P< 0.05) among different body condition (3.59%) large in volume (Table 4).scores.The prevalence was 12.42% and 18.92% in adult and old animals, respectively, but there was no Financial losses: The economic loss due to statistically significant (P>0.05)difference between hydatidosis was the summation of the loss due to age groups (Table 1).
carcass weight and the loss due to organ condemnation Therefore, the estimated economic loss in cattle parasites have no selective affinity for any particular of Ethiopia and reported the prevalence of 46 % in organ, and location of hydatid cyst in animal is medium, 24 % in high and 25 % low altitude zones.As controlled by filtering action of capillaries.This could high as 68% prevalence was also reported in sheep by be due to the fact that lungs and liver possesses the first Sissay et al. (2008).A possible reason for the great capillaries sites encountered by the migrating difference in the prevalence of hydatidosis might be Echinococcus onchosphere (hexacanth embryo) due to the contact between large numbers of stray dogs which adopt the portal vein route and primarily with the herd of cattle.Dogs, which are the primary negotiate hepatic and pulmonary filtering system factor for the disease transmission, are used as guards sequentially before any other peripheral organ is for herds and are routinely fed with uncooked offal involved, but onchosphers which traverse these will which deemed unfit for human consumption ( (Getaw et al., 2010).considerable economic loss in livestock production in Higher numbers of small sized and calcified cysts and around Dessie.Therefore, proper meat inspection were found in liver and this could be due to the and disposal of condemned organs are essential to reticulo-endothelial and connective tissue reaction of reduce the financial losses and safeguard the public.In a the organ (Kebede et al., 2009 ).The liver infection addition to this, the construction of well equipped may be a reflection of the route of parasite entry and abattoirs and enhancement of awareness of people seems to support the hypotheses of hepatic portal about the economic and public health importance of distribution of the onchosphere leading to the liver the disease are also crucial.infection.Out of 195 hydatid cysts 153 (78.46%), 41 The study was conducted from October particularly the lung, kidney, liver, spleen, and heart 2010 to March 2011 at Dessie municipal abattoir, (Getaw et al., 2010).The infected organs from each Northeast Ethiopia.Dessie town is situated at the positive animal were collected; the total number of North-east part of Ethiopia at a distance of about 400 hydatid cysts were counted per infected organ and km away from the capital (Addis Ababa), located at recorded.

Organ distribution and cysts Evaluation beef
were obtained from information gathered from Organ distribution: The postmortem inspection local butchers.Annual economic loss due to organ revealed that different organs were affected with condemnation was determined by considering annual hydatid cyst(s).The highest proportions of hydatid slaughter rate of cattle and prevalence of hydatidosis cyst were recorded in the lungs (68.67%) followed by per organ and an estimated 5 % carcass weight loss liver (14.46%), kidney (6.02%), heart (1.2%), spleen (Getaw et al., 2010) was considered.Average carcass whereas 9.64% were found both in the lung and liver weight of Ethiopian local breed cattle is estimated as (Table 2).108 kg (Negassa et al., 2010).The total economic loss was calculated as the summation of cost of offal Number and Viability test: Both single and multiple condemned plus the cost of carcass weight losses infections of organs were recorded.Out of the total d (Kebede et al., 2009 ; Getaw et al., 2010).

Table - 1. Prevalence of based on age and body condition score of animals
Cyst Viability, Organ Distribution and Financial Losses due to Hydatidosis in Slaughtered Cattle prevalence of 13.61% which agrees with the findings cyst infection.Polydorous (1981) explained that in a moderate to severe infection the parasite may cause of Kebede et al. (2009 ) 16% in Wolaita Sodo town and b retarded performance and growth, reduced quality and Kebede et al. (2009 ) 15.2% in Birre-Sheleko and yield of meat and milk as well as live weight loss and Dangila abattoirs.estimated a 5 and 16% weight loss in Yugoslavia and However, the present study disagree with reports e Bulgaria, respectively. of Kebede et al. (2009 ) 34.05% in Bahir Dar town and In this study, it had been found that hydatid cyst Tolosa et al. (2009) 31.44% in Jimma town.Jobre et occur predominantly in lungs and liver.Immature al. (1996) studied hydatidosis in three selected regions

Table - 3: cyst fertility and viability in different organs
Getaw et reach the systemic circulation and hydatid have been al., 2010).The other possible reason for the variation found in many organs and tissues (Urquhart et al., in prevalence rate in different countries and regions

Table - 4: cyst fertility and viability in different organs n=number
, %=percentage number of medium and large sized cysts than liver.Conclusion Larger size of cysts in the lungs may be due toIn conclusion, hydatidosis is prevalent and causes relatively softer constancy