Evaluation of zoonotic platyhelminthe infections identified in slaughtered livestock in Iran, 2015-2019.

BACKGROUND: Platyhelminth infections of livestock can result in considerable economic losses. This study aims to evaluate the spatial frequency of cystic echinococcosis (CE), dicrocoeliasis, and fascioliasis in livestock slaughtered in Iran during the years 2015-2019 and estimate direct costs associated with organ condemnation due to these parasites. METHODS: Abattoir data from 413 abattoirs representing all 31 Iranian provinces were collected from the Iran Veterinary Organization. Infection prevalence was calculated per year at the province level. The Local Moran's I statistic was performed to evaluate spatial autocorrelation of animals positive at slaughter for the years 2015-2019. Direct costs associated with condemned livers were calculated for each parasitic condition, with costs associated with condemned lungs also included for CE. RESULTS: Overall prevalence values for the study timeframe were as follows: sheep and goat fascioliasis 1.56% (95% CI: 1.56-1.56%), cattle fascioliasis 3.86% (95% CI: 3.85-3.88%), sheep and goat dicrocoeliasis 4.63% (95% CI: 4.62-4.63%), cattle dicrocoeliasis 3.08% (95% CI: 3.07-3.09%), sheep and goat CE 5.32% (95% CI: 5.32-5.33%), and cattle CE 7.26% (95% CI: 7.24-7.28%). Northwest Iran had the highest prevalence of CE and fascioliasis. High infection areas for Dicrocoelium spp. included the provinces of Zanjan, Gilan, Qazvin, and Tehran, which are located in northern Iran. Direct economic losses for sheep and goat fascioliasis, dicrocoeliasis, and CE for the study period were US$13,842,759, US$41,771,377, and US$22,801,054, respectively. Direct economic losses for cattle fascioliasis, dicrocoeliasis, and CE for the study period were US$1,989,200, US$1,668,986, and US$2,656,568, respectively. CONCLUSION: Our findings provide valuable data for future monitoring of these important parasitic diseases in Iranian livestock. Disease control strategies are required to reduce the economic and public health impact of these platyhelminths.

Production responses and cost-benefit of long-acting pre-lambing anthelmintic treatment of yearling ewes in two commercial flocks in New Zealand.

AIMS: To investigate the production responses and cost-benefit of administering a controlled-release anthelmintic capsule (CRC) to pregnant yearling ewes prior to lambing. METHODS: Yearling ewes from two commercial sheep flocks (A, n=489; B, n=248) in the North Island of New Zealand were enrolled in the study. Prior to lambing, CRC containing albendazole and abamectin were administered to half the ewes while the other half remained untreated. Ewe liveweights and body condition scores were measured prior to lambing, at weaning and, for Flock B, prior to subsequent mating. Lambs were matched to dams shortly after birth and the weight and number of lamb weaned per ewe were determined. A cost-benefit analysis was undertaken for Flock B considering the increased weight of lamb weaned per ewe, and the weight of ewes at the next mating and the benefit in terms of lambs born. RESULTS: The mean weight at weaning of treated ewes was greater for treated than untreated ewes by 2.76 (95% CI 0.64-4.88) kg in Flock A (p<0.001) and 2.35 (95% CI -0.41-5.12) kg in Flock B (p=0.003); the weight of lamb weaned per ewe was greater for treated than untreated ewes by 1.43 (95% CI -0.71 to -3.49) kg in Flock A (p=0.041) and 3.97 (95% CI 1.59-6.37) kg in Flock B (p<0.001), and ewe liveweight prior to subsequent mating was greater for treated than untreated ewes in Flock B by 4.60 (95% CI 3.6-5.6) kg (p<0.001). There was no difference in the percentage of lambs reared to weaning between treated and untreated ewes in either flock (p>0.8). The overall cost-benefit of treatment for Flock B was NZ$9.44 per treated ewe. CONCLUSIONS AND CLINICAL RELEVANCE: Pre-lambing CRC administration to yearling ewes resulted in increased ewe weaning weights and weight of lamb weaned in both the flocks studied. There was an economic benefit in the one flock where this was assessed.

A socio-economic study of Fasciola infections in cattle and sheep at the Etoudi slaughterhouse, Yaoundé, Cameroon.

A cross-sectional socio-economic study of fascioliasis in livestock was carried out at the Livestock Development Cooperation (SODEPA) slaughterhouse in Etoudi, Yaoundé during the periods covering the beginning and late dry season in the northern and eastern regions of Cameroon. A total of 768 cattle and 267 sheep were inspected for the presence of Fasciola species. The overall infection rate in cattle and sheep was 18% (n = 767) and 27% (n = 267), respectively. For the animals that were Fasciola positive, a total of 267.86 kg of liver in cattle was condemned, resulting in a loss of US$1124, while a total of 57 kg of liver was condemned from the sheep population, amounting to a loss of US$114. A total of US$76,097 was determined as losses incurred from condemnation of liver for both cattle and sheep per annum based on the total number slaughtered each year. The findings indicate that fascioliasis is present in cattle and sheep slaughtered in Cameroon and that it causes great economic losses due to condemnation of liver. The local climatic conditions, husbandry systems and the presence of snails (intermediate hosts) are probably the main factors influencing the incidence of the disease and may account for the epidemiological significance found in this study.

Analysis of pastoralists' perception on challenges and opportunities for sheep and goat production in Northern Kenya.

Small ruminants' production contributes to livelihood of pastoral communities, but this faces myriad constraints. This study aimed at identifying challenges facing producers of small ruminants, prioritizing diseases and their control measures and documenting opportunities for improvement. Sixteen focus group discussions with livestock owners and 13 key informant interviews were done in selected areas in Mandera County, Northern Kenya, and both quantitative and qualitative data collected using a questionnaire guide. Occurrences of diseases (27.4%) and drought (25%) were consistently ranked high in all groups. Other production challenges included increased predation of livestock, inadequate delivery of veterinary services, and increased livestock mortalities. Peste des Petit ruminants was ranked high with a median rank of 21.5%, while contagious caprine pleuropneumonia and sheep and goat pox were ranked second and third, respectively. Other diseases included tick-borne diseases, helminthosis, and pneumonia. Vaccination was ranked as the most effective control strategy for infectious diseases. Other control measures included recitation of Quran and cauterization. However, several opportunities exist for support of small ruminants' production: increased budgetary allocation for disease control by government, initiation of projects that enhance livestock production in the region by government and its development partners. These findings are useful for policy makers for disease control and organizations that are working on projects that focuses on enhancement of pastoralists' resilience, while future research could also identify appropriate technologies that reduces these impacts.

Efficacy and economic analysis of two treatment regimens using toltrazuril in lambs naturally infected with Eimeria spp. on pasture.

This study evaluated the efficacy and the economic viability of two anticoccidial treatment regimens tested in lambs naturally exposed to Eimeria spp. re-infections in a grazing system during a 140-day period. Twenty-four suckling lambs were distributed into three groups based on the individual count of oocysts per gram of feces (OPG) and body weight. Animals were treated with toltrazuril 5% (20 mg/kg) at 14- (GI) or 21-day (GII) intervals, and GIII was kept as untreated control. A cost-benefit analysis of each treatment regimen was calculated. Additionally, economic analysis was performed on four hypothetical scenarios, in which lambs could be having 10, 25, 50, or 85% decrease in their expected body weight gain due to clinical. Efficacy of toltrazuril against Eimeria spp. was 96.9-99.9% (GI) and 74.2-99.9% (GII). E. ovinoidalis was most frequently identified, but no clinical signs of coccidiosis were observed in lambs. There were no differences in weight gain among the groups. The cost of treatment per lamb was $13.09 (GI) and $7.83 (GII). The estimation model showed that the cost-benefit ratio favored treatment with toltrazuril when lambs fail to gain weight. In the studied flock, the break-even point for toltrazuril administered at 14-day intervals was reached with 85% decrease in mean weight gain. In conclusion, toltrazuril can be used at 14-day intervals to control Eimeria spp. (re)-infection in lambs raised on pasture. This treatment regimen was not economically feasible for subclinical coccidiosis; however, it may be feasible when used to prevent weight loss caused by clinical coccidiosis.

Economic assessment of an emerging disease: the case of Schmallenberg virus in France.

Schmallenberg virus (SBV) was first detected in 2011 in Germany and then in France in 2012. This study simulates the production of different ruminant systems in France and estimates, through partial budget analyses, the economic cost of SBV at the farm level, under two disease scenarios (a high-impact and low-impact scenario). A partial budget is used to evaluate the financial effect of incremental changes, and includes only resources or production that will be changed. In the high-impact scenario, the estimated impact of SBV ranged from €23 to €43 per cow per year and €19 to €37 per ewe per year. In the low-impact scenario, it was approximately half (for cows) or one-third (for ewes) of this amount. These financial impacts represent 0.6% to 63% of the gross margin, depending on the chosen scenario and the livestock system being considered. The impacts of SBV come mainly from: the extra costs from purchasing and raising replacement heifers and losses in milk production (dairy cows); the losses in calf or lamb production (beef systems and meat sheep); and the losses in milk production and from unsold replacement lambs (dairy sheep). The use of integrated production and economic models enabled the authors to estimate the cost of SBV and to tackle the problem of scarce data, which is a difficulty for most emerging diseases, by their very nature. It also allowed the authors to develop an accurate disease impact assessment for several production systems, over a short time span. Extrapolating from this economic assessment to predict the scenario in coming years depends on the immunity period of the disease and the length of the production cycles.

Le virus de Schmallenberg a été détecté pour la première fois en 2011 en Allemagne, puis en France en 2012. Les auteurs présentent une étude de simulation de plusieurs systèmes de production de ruminants en France, dont l'objectif était d'estimer, à partir d'analyses budgétaires partielles, les coûts économiques du virus de Schmallenberg à l'échelle des exploitations, sous deux scénarios différents (hypothèses d'un fort impact et d'un faible impact de la maladie, respectivement). Une analyse budgétaire partielle sert à évaluer les conséquences financières d'un changement graduel et ne prend en compte que les modifications effectives en termes de ressources et de production. Dans l'hypothèse d'un impact fort de la maladie, l'impact annuel estimé du virus de Schmallenberg variait de 23 à 43 euros par vache et de 19 à 37 euros par brebis. Dans l'hypothèse d'un impact faible, l'impact annuel était deux fois moindre chez les vaches et trois fois moindre chez les brebis que dans la première hypothèse. Ces impacts financiers représentent 0,6 % à 63 % de la marge brute en fonction du scénario choisi et du système de production. Les impacts du virus de Schmallenberg découlent principalement des coûts supplémentaires induits par l'achat et le maintien de génisses de remplacement et d'une baisse de la production de lait (vaches laitières), des pertes de veaux ou d'agneaux (bovins et ovins de boucherie), d'une baisse de la production de lait et du coût des agnelles de remplacement invendues (brebis laitières). L'utilisation de modèles intégrant les aspects économiques et les données de production a permis aux auteurs d'estimer le coût du virus de Schmallenberg malgré la pénurie de données, s'attaquant ainsi à une difficulté inhérente à la plupart des maladies émergentes. Cela leur a également permis d'effectuer une évaluation précise de l'impact sanitaire dans plusieurs systèmes de production, sur une durée courte. La possibilité d'extrapoler à partir de cette évaluation économique un scénario pour les années à venir dépend de la période d'immunité vis-à-vis de la maladie et de la durée des cycles de production.

El virus de Schmallenberg fue detectado por primera vez en 2011 en Alemania y ulteriormente en 2012 en Francia. Los autores describen un estudio en el que se simularon distintos sistemas de producción de rumiantes en Francia y se estimó, con análisis presupuestarios parciales, el coste económico que entrañaría para una explotación el virus de Schmallenberg en dos hipotéticas situaciones sanitarias (una situación con efectos profundos y otra con efectos leves). El análisis presupuestario parcial sirve para evaluar los efectos económicos de cambios graduales, e incluye únicamente aquellos recursos y aspectos de la producción que experimentarán cambios. En la hipótesis de efectos profundos, el impacto estimado de la infección por el virus de Schmallenberg oscilaba entre 23 y 43 euros anuales por vaca y entre 19 y 37 euros anuales por oveja hembra. La hipótesis de efectos leves deparaba importes de aproximadamente la mitad (en el caso de las vacas) o un tercio (en el de las ovejas). Este impacto económico representa del 0,6% al 63% del margen bruto, dependiendo de la hipótesis elegida y del sistema productivo de que se trate. Los efectos de la infección por el virus de Schmallenberg se concretan básicamente en: los costos suplementarios derivados de adquirir y criar vaquillas de sustitución y de obtener una menor producción de leche (vacas lecheras); las pérdidas de terneros o corderos (sistemas de bovino u ovino cárnicos); y los costos derivados de la menor producción de leche y de no vender las corderas de sustitución (ovejas lecheras). El uso de modelos que integran los factores productivos y económicos sirvió a los autores para estimar el costo del virus de Schmallenberg a pesar de la escasez de datos, que, por la propia naturaleza de las enfermedades emergentes, es una dificultad común a la mayoría de ellas. También les permitió evaluar con exactitud el impacto de la enfermedad en distintos sistemas productivos en un breve lapso de tiempo. La realización de extrapolaciones a partir de esta evaluación económica para pronosticar la situación en años venideros depende del periodo de inmunidad respecto de la enfermedad y de la duración de los ciclos productivos.

Epidemiological updates and economic losses due to Taenia hydatigena in sheep from Sardinia, Italy.

The aim of this study was to investigate the epidemiology and transmission of Taenia hydatigena in sheep and dogs from Sardinia and the economic estimation of losses due to this metacestodosis in lambs. A total of 7781 Sarda breed lambs were examined at abattoirs for the detection of Cysticercus tenuicollis or necrotic-haemorrhagic tracks of their migration. Morphological and molecular identification of parasites was carried out. Individual faecal samples from 300 dogs were examined for copromicroscopic investigations and coproELISA assay. An overall prevalence of 14.6% for T. hydatigena cysticercosis was found in the examined lambs. In total, 10,807 parasitary tracks were found, with an abundance of 1.39 and an average intensity of 9.52. The molecular analysis of the isolates showed an overall pairwise nucleotide divergence for the CO1 and ND1 was of 0-3.1 and 0-3.3%, respectively. Low intra- and interspecific variation was recorded for C. tenuicollis isolates used in this study which suggested the absence of differentiation. Microscopic examination of dog faeces showed a total prevalence of 31.3% for endoparasites in the examined samples (94/300). Taeniid eggs were found in 8.3% of the dogs. The results of the monoclonal antibody ATH4 ELISA test showed a prevalence of 11% (33/300) for T. hydatigena coproantigens. The total economic costs related to cysticercosis amounted to almost € 330,000. The prevalence of C. tenuicollis in 14.6% of 30-40-day-old lambs highlights the high parasitic pressure by T. hydatigena in the territory of Sardinia, Italy.

Slaughterhouse prevalence of ovine paratuberculosis in Southern India.

Ovine paratuberculosis is a threat to small animal holders in terms of economic loss such as reduced growth performance and early culling. In order to study the slaughterhouse prevalence of ovine paratuberculosis, the slaughterhouse sheep samples (which are poor in body condition) collected over a period of two and half years from 1,034 suspected male sheep (poor in body condition) and 40 normal sheep (good body condition and subsequently negative by all the diagnostic tests employed) aged between 16 and 18 months were slaughtered at various abattoirs of Tamil Nadu. All the sheep taken in this study were maintained in almost same management conditions. DNA was extracted from 1,034 intestinal tissue and mesenteric lymph node and 121 were positive by IS 900 PCR. One hundred ten and 56 were positive by absorbed ELISA and Ziehl-Neelsen staining, respectively. In histopathology, 28 animals showed gross lesions of paratuberculosis infection (20-multibacillary and 8-paucibacillary forms). Out of 1,034 sheep tissues cultured, 32 showed cultural growth in Middlebrook 7H9 and 26 in Herrold's egg yolk medium. None of the 40 normal sheep were positive by any of the tests employed. In general, the mean body weight of paratuberculosis-affected animal either by any one of the tests employed was less than the non-affected sheep. The approximate economic loss per sheep/farmer/year is around Rs 1,840 (US$ 38.33) in paratuberculosis-affected sheep.

Control strategies for peste des petits ruminants in small ruminants of India.

Peste des petits ruminants (PPR) is a contagious viral disease of small ruminants. It is endemic in several African, Middle Eastern and Asian countries, including India. India has recently taken comprehensive steps to deal with PPR through the development and production of potent vaccines and monoclonal-antibody-based diagnostic kits, while also gathering baseline information on the disease situation and human resources. As a result, PPR can now be controlled by focused vaccinations in high-risk populations of sheep and goats, followed by mass vaccination campaigns. Mass vaccination campaigns must achieve high levels of herd immunity (70% to 80%) to block the epidemic cycle of the virus. With the tools currently available, disease control and subsequent eradication programmes for PPR may be a feasible option, following the example of the National Rinderpest Eradication Programme, which has successfully eradicated rinderpest from India. An understanding of the cultural and socio-economic circumstances of goat and sheep owners and a keen watch on the endemic nature of PPR in neighbouring countries will enhance the success of this approach. Coordinated efforts from all stakeholders, combined with proper funding and execution of control programmes, will be needed to achieve the goal of a PPR-free India. In addition, the availability of effective combined vaccines of PPR with goat pox or sheep pox offers a cost-effective way of simultaneously launching control programmes against all three of these diseases.

Sero-epidemiological study of peste des petits ruminants in sheep and goats in India between 2003 and 2009.

This study describes the serosurveillance of peste des petits ruminants (PPR) in sheep and goats that was carried out between 2003 and 2009 using serum samples from animals suspected of PPR that were submitted to the Rinderpest and Allied Disease Laboratory (Division of Virology of the Indian Veterinary Research Institute [IVRI]). A total of 2,197 serum samples from sheep and 2,687 from goats were screened for PPR virus (PPRV) antibody using a monoclonal antibody-based competitive enzyme-linked immunosorbent assay developed at IVRI. Screening of the 4,884 serum samples showed that the prevalence of PPRV antibody in sheep and goats was 41.01% (95% confidence interval [CI]: 31.86 to 50.16) and 46.11% (95% CI: 37.18 to 55.04), respectively, with an overall prevalence of 43.56% (95% CI: 36.78 to 50.34) during the period. This indicates increased and widespread infection with the virus in India compared with earlier reports, which is attributed to the variations in sheep and goat husbandry practices in different regions, the agro-climatic conditions, the topography of different states, the socio-economic status of individual farmers and the migration of livestock in India.

Determination of prevalence and economic impact of ovine footrot in central Kashmir India with isolation and molecular characterization of Dichelobacter nodosus.

The present study determines the prevalence, economic impact of virulent footrot in central Kashmir, India, along with isolation and molecular characterization of Dichelobacter nodosus (D. nodosus) where so far no such work has been carried out. Over all 12.54% prevalence of footrot was recorded in central Kashmir with highest (15.84%) in district Srinagar, and least (10.89%) in district Budgam, while it was 13.28% in district Ganderbal. Overall economic impact of footrot was estimated to the tune of Rs 15.82 million annually to the sheep farming in central Kashmir. Out of 370 samples collected from footrot lesions of naturally infected sheep, 200 (54.05%) detected D. nodosus positive by polymerase chain reaction (PCR). Out of these, 132 (66.00%) samples carried serogroup B of D. nodosus, five (2.50%) serogroup E, one (0.50%) serogroup I, while, 53 (26.50%) had mixed infection of serogroups B and E, four (2.00%) of serogroups B and I, two (1.00%) of serogroups B and G and the remaining three (1.50%) samples harboured the mixed infection of serogroups B, E and I. Serogroup G was detected for the first time in India. Over all serogroup B was most frequent (97.0%) followed by E (30.5%), while serogoups I (4.0%) and G (1.0%) were least prevalent. A total of 265 D.nodosus strains were isolated out of which 194 (73.20%) were typed as serogroup B, 61 (23.01%) as serogroup E, eight (3.01%) as serogroup I and remaining two (0.75%) belonged to serogroup G. Out of 265 D. nodosus isolates, 164 (61.88%) possessed intA (integrase) gene, thus were considered as virulent strains. Serogroup wise intA gene was found in 121(62.37%) isolates of serogroup B, 36 (59.01%) of E, two (100%) of G and five (62.50%) of I. Out of 20 randomly selected isolates subjected to gelatin gel test, 16 isolates with intA gene produced thermostable protease while four isolates without intA gene revealed the production of thermolabile protease. This indicated a good co-relation between presence of intA gene and gelatin gel test in determination of the D. nodosus virulence. Thus the present investigation suggests the incorporation of serogroups B and E, based on their predominant prevalence, in the formulation of an effective bivalent vaccine to combat footrot in central Kashmir.

An abattoir-based study on the prevalence and economic losses due to cystic echinococcosis in slaughtered herbivores in Ahwaz, south-western Iran.

A 10-year (1998-2008) retrospective study was carried out to investigate the prevalence and long-term trend of hydatid disease in slaughtered herbivores in the large complex abattoir of Ahwaz (the capital of Khuzestan province, south-western Iran). A total of 3,583,417 animals including 2,815,982 sheep, 427,790 goats and 339,645 cattle were inspected macroscopically for hydatid cysts in the 10-year period, and overall 155,555 (4.24%) livers and 228,172 (6.37%) lungs were condemned. Cystic echinococcosis (CE) was responsible for 36.08% and 48.04% of total liver and lung condemnations, respectively. The prevalence of pulmonary hydatid disease in sheep, goats and cattle was 2.22, 5.43 and 6.99%, respectively; on the other hand, the prevalence of hepatic hydatid disease for those animals was 1.26, 2.57 and 2.80%, respectively. Data showed an overall downward long-term trend for CE in all livestock slaughtered during the study period (P < 0.01). Lung condemnation due to CE was significantly more common than liver condemnation for each animal separately (P < 0.001). The prevalence of liver and lung hydatidosis in sheep was significantly lower than that in other livestock (P < 0.001). The prevalence of hydatid disease recovered from the sheep, cattle and goats varied in different seasons, but there was no statistical difference between various seasons. The odds ratio of lung and liver condemnations due to hydatidosis showed a slightly different pattern in some years; however, the overall declining trend was still observed. The total annual economic loss incurred due to hydatidosis in all ruminants slaughtered at Ahwaz municipal abattoir was estimated to be US$459,659.6, based on the market prices in the year 2008. This number corresponds to a loss of US$300,620.4 for cattle, US$123,490.0 for sheep and US$35,549.2 for goats. The current results provide baseline data for the future monitoring of this potentially important disease in the region, and also suggest that a thorough investigation leading to a disease control strategy is required to reduce the economic and public health consequences of CE.

Prevalence of Liver Hydatidosis and Its Economic Significance in Sheep Slaughtered in a Private Abattoir in Konya

Objective: This study aimed to determine the prevalence of liver hydatidosis in sheep slaughtered in a private slaughterhouse in Konya and to estimate the economic loss incurred because of the disease. Methods: The study was conducted over a period of 12 months between 1 June 2018 and 31 May 2019. Given that the aim of this investigation was to determine the prevalence of liver hydatidosis, only the livers of 41,002 sheep were examined for hydatid cysts. Results: The liver of 810 (1.97%) sheep was found to be infected with hydatid cysts during the study period. The infection rate was determined as 5.34% in animals older than one year of age and 1.68% in animals less than one year of age. Regardless of the age group, the highest infection rate was found in autumn (3.34%), while the lowest infection rate was seen in spring (0.84%). In the sheep, the highest infection rate was in December (17.2%), and in lambs, it was in June (2.9%). On the other hand, the lowest infection rate in sheep was observed in November (1.8%), while the lowest infection rate in lambs was found in April (0.7%). The total economic loss incurred due to the annihilated livers was estimated as 36,450 TL (6.417$). Regardless of the number of cysts and degree of infection, the infected livers were completely discarded. The economic loss incurred due to the discarded livers was estimated by considering the 2019 offal prices. Conclusion: Based on the data obtained from this study, it could be concluded that hydatidosis still exists in Konya as well as throughout Turkey and that it causes serious economic loss.

The abattoir condemnation of meat because of parasitic infection, and its economic importance: results of a retrospective study in north-eastern Iran.

In nine districts in the north of Khorasan province, in north-eastern Iran, a 5-year retrospective study was carried out to determine the prevalences, in livestock slaughtered in abattoirs, of the parasitic infections responsible for the condemnation of the animals' carcasses and viscera (and the economic importance of such infections in terms of lost meat and offal). Between 20 March 2005 and 19 March 2010, 436,620 animals (45,360 cattle, 275,439 sheep, 115,674 goats and 147 camels) were slaughtered in the study area and the livers of 30,207 (6.9%), the lungs of 23,259 (5.3%) and the carcasses of 1072 (0.2%) of these animals were condemned. Almost all (92.4%) of the condemned livers, most (68.9%) of the condemned lungs but only 10.8% of the condemned carcasses were rejected because of parasitic infection. The parasitic lesions observed in the condemned livers were attributed to Echinococcus granulosus, Fasciola hepatica and/or Dicrocoelium dendriticum (cattle, sheep and goats) or entirely to E. granulosus (camels). All the parasitic lesions observed in the condemned lungs (which also came from cattle, sheep, goats and camels) were attributed to E. granulosus. Sarcocystis cysts and/or Taenia cysticerci were found in ovine muscle while only Taenia cysticerci were detected in bovine muscle (no parasitic lesions were observed in the muscles of the goats and camels). Parasites were responsible for 80.8% of the condemned organs or carcasses, and the value of the food lost because of parasite-related condemnation (based on market prices in 2010) was estimated to be U.S.$421,826 (U.S.$47,980 for cattle, U.S.$316,344.0 for sheep, U.S.$57,372 for goats and U.S.$130 for camels). The parasites contributing most to the condemnation of otherwise marketable organs and muscles were E. granulosus (52.2%) and D. dendriticum flukes (29.5%). These parasites clearly remain too common and cause considerable economic loss in Khorasan and, presumably, other areas of Iran.

Increasing accuracy in estimation of economic values for resistance to gastrointestinal helminths in meat sheep.

The impact of utilising different indices and numbers of index traits in estimation of economic values (EVs) for resistance to gastrointestinal (GI) helminths were investigated. Seven indices based on yearling weight (YW), litter size (LS) and ewe live weight (ELW) were evaluated under a scheme that considered individual records (Scheme 1) and one that utilised extra information from individual's relatives (Scheme 2). Under an objective where index response in YW was maximum (R(IYW) = max) economic values were US$ 0.00, 0.41, 0.35 and 1.58 in scheme 1 and -0.07, 0.25, -1.10 and -0.02 in scheme 2 for indexes 1, 2, 3 and 4 respectively. In the determining the effect of the number of index traits on the estimates of EVs, calculations were done for five breeding objectives. Eight scenarios (indices) under each objective that differed in the number of traits considered were evaluated. In all scenarios, EVs under R(IYW) = max were positive and were US$ 0.00, 0.79, 2.68, 2.66, 2.66, 2.62, 2.44 and 2.62 for scenarios 1-8 respectively. Generally, economic value estimates varied across breeding schemes and objectives.

Economic and public health importance of Toxoplasma gondii infections in sheep: 2009-2020.

Toxoplasma gondii infections are common in humans and animals worldwide. The present review summarizes worldwide information on the prevalence of clinical and subclinical infections, epidemiology, diagnosis, control, and genetic diversity of T. gondii in sheep in the past decade. There is debate and uncertainty concerning repeat congenital infection as evidenced by finding T. gondii DNA in progeny of chronically infected sheep. However, there is no concrete evidence that T. gondii is the cause of repeated abortions in sheep. Recent data concerning pathogenesis of abortion in acutely infected sheep are reviewed. PCR-RFLP typing of T. gondii DNA derived from viable T. gondii isolates or tissues of infected sheep revealed low genetic diversity in sheep in Europe, Africa, Asia and North America but high diversity in South America. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers.

Initial assessment of the economic burden of major parasitic helminth infections to the ruminant livestock industry in Europe.

We report a European wide assessment of the economic burden of gastrointestinal nematodes, Fasciola hepatica (common liver fluke) and Dictyocaulus viviparus (bovine lungworm) infections to the ruminant livestock industry. The economic impact of these parasitic helminth infections was estimated by a deterministic spreadsheet model as a function of the proportion of the ruminant population exposed to grazing, the infection frequency and intensity, the effect of the infection on animal productivity and mortality and anthelmintic treatment costs. In addition, we estimated the costs of anthelmintic resistant nematode infections and collected information on public research budgets addressing helminth infections in ruminant livestock. The epidemiologic and economic input data were collected from international databases and via expert opinion of the Working Group members of the European Co-operation in Science and Technology (COST) action COMbatting Anthelmintic Resistance in ruminants (COMBAR). In order to reflect the effects of uncertainty in the input data, low and high cost estimates were obtained by varying uncertain input data arbitrarily in both directions by 20 %. The combined annual cost [low estimate-high estimate] of the three helminth infections in 18 participating countries was estimated at € 1.8 billion [€ 1.0-2.7 billion]. Eighty-one percent of this cost was due to lost production and 19 % was attributed to treatment costs. The cost of gastrointestinal nematode infections with resistance against macrocyclic lactones was estimated to be € 38 million [€ 11-87 million] annually. The annual estimated costs of helminth infections per sector were € 941 million [€ 488 - 1442 million] in dairy cattle, € 423 million [€ 205-663 million] in beef cattle, € 151million [€ 90-213 million] in dairy sheep, € 206 million [€ 132-248 million] in meat sheep and € 86 million [€ 67-107 million] in dairy goats. Important data gaps were present in all phases of the calculations which lead to large uncertainties around the estimates. Accessibility of more granular animal population datasets at EU level, deeper knowledge of the effects of infection on production, levels of infection and livestock grazing exposure across Europe would make the largest contribution to improved burden assessments. The known current public investment in research on helminth control was 0.15 % of the estimated annual costs for the considered parasitic diseases. Our data suggest that the costs of enzootic helminth infections which usually occur at high prevalence annually in ruminants, are similar or higher than reported costs of epizootic diseases. Our data can support decision making in research and policy to mitigate the negative impacts of helminth infections and anthelmintic resistance in Europe, and provide a baseline against which to measure future changes.

Milk production losses in Latxa dairy sheep associated with small ruminant lentivirus infection.

Visna/Maedi is a disease of sheep caused by small ruminant lentivirus (SRLV) infection that is widespread throughout the world and that has been recognized to be present in the Basque Country (Spain) since the early 1980's. Nearly seven decades of studies have improved the knowledge on its clinical signs and epidemiology. However, its slow progressive nature, subclinical most of the time, makes difficult to assess its real impact on productive traits, a question of critical importance to balance out the economic costs it causes and the benefits of designing and deploying an eradication program. Development of a dairy breeding program since the 90 s in the local Latxa sheep population has provided data on milk productivity in several flocks where SRLV infection prevalence has been continuously monitored. This study analyses retrospectively the association between SRLV prevalence and production variables during ten yearly lactations in three Latxa dairy flocks with medium-high SRLV seroprevalence. Our results indicate that average standard lactation of seropositive sheep was 6.7 % lower than controls. The largest differences (p < 0.001) were observed at the ewe lifetime peak of production between second and fourth lactations. Lifelong milk and lamb production data indicated even a higher impact, with costs rising up to nearly 50 €/ewe/year. This substantial production decrease associated with subclinical SRLV infection in Latxa dairy sheep supports the benefit of establishing a SRLV control program. A rough cost-benefit analysis indicated that even in a medium-yielding breed, testing expenses would be largely covered by milk production improvement.

Risk factors and productivity losses associated with Mycoplasma ovipneumoniae infection in United States domestic sheep operations.

Association of Mycoplasma ovipneumoniae with pneumonia in domestic small ruminants has been described in Europe, Asia, and New Zealand but has received less attention in the United States. In 2011, the US Department of Agriculture's National Animal Health Monitoring System detected M. ovipneumoniae shedding in 88% of 453 domestic sheep operations tested in 22 states that accounted for 85.5% of US ewe inventory in 2001. We evaluated factors associated with M. ovipneumoniae infection presence and prevalence, and we compared health, lamb production, and ewe losses in infected and uninfected operations. M. ovipneumoniae detection was more common in larger operations than in smaller operations. Both likelihood of detection (at the operation level) and within-operation prevalence were higher in operations with more open management practices than in operations with more closed management practices. M. ovipneumoniae-positive operations showed significantly lower lambing rates and lower rates of lamb survival to weaning after accounting for differences in operation size and management practice. While its effect on any single rate was not particularly large, in aggregate we estimated that M. ovipneumoniae presence was associated with an approximately 4.3% reduction in annual lamb production.

Sheep blowfly strike: the cost of control in relation to risk.

Sheep blowfly strike (ovine cutaneous myiasis) is a widespread economic and welfare problem in sheep husbandry in many parts of the world. Strike incidence is determined by a complex interaction of fly abundance, host susceptibility and climate, combined with farmer husbandry and intervention strategies. Sheep farmers adopt a range of approaches to the type and timing of the management used for the control of blowfly strike, the rational basis for which is often not robust. Here a deterministic model, based on existing data relating to fly abundance, seasonal risk and strike incidence, is used to compare the variable costs associated with different strike management strategies. The model shows that not employing prophylactic treatment is the lowest cost strategy only where strike risk is low. In all other circumstances, prophylactic treatment incurs lower costs than not doing so, because the deaths associated with strike outweigh the costs of prophylactic treatment. Lamb treatment, in particular, has a substantial effect on strike and cost reduction, since lambs are the most abundant age-class of animals and are at the highest risk over the period when fly abundance is the greatest. Early-season treatment of ewes before shearing is also an important component of the lowest cost strategies, particularly when the blowfly season is extended. While the rational choice of the most appropriate strike management strategy is essential in the context of farm economics, welfare considerations lend added importance to treatment decisions that reduce strike incidence.