Death Of Sheep Research Articles

Impact of VP2 structure on antigenicity: comparison of BTV1 and the highly virulent BTV8 serotype.

Bluetongue virus (BTV) is an agriculturally and economically significant insect-borne virus that causes serious illness and death in sheep and other domestic and wild ruminants in large areas of the world. Numerous BTV serotypes exist, and distant serotypes exhibit unique neutralizing antibody profiles, which target the outermost capsid protein VP2. The predominant serotype-specific nature of the antibody response to VP2 is a barrier to the development of broad-spectrum prophylactic BTV vaccine candidates. Although VP2 is the main serotype determinant of BTV, the structural basis of serotype specificity has not been investigated. In this study, we utilized the recently available atomic structure of VP2 with a modeled tip domain to carry out in silico structural comparisons between distant serotypes BTV1 and BTV8. These analyses identified structural differences in the tip domain, positioned at the apex of VP2, and informed the design of mutant VP2 constructs. Dissection of tip domain antigenicity demonstrated that the region of structural difference between BTV1 and highly virulent BTV8 was a target of BTV neutralizing antibodies and that mutation of this region resulted in a loss of neutralizing antibody recognition. This study has for the first time provided insights into the structural differences, which underpin the serotype-specific neutralizing antibody response to BTV.IMPORTANCEThe immune system can protect against virus infection by producing antibodies, which bind and inhibit the virus from infecting the susceptible host. These antibodies are termed neutralizing antibodies and generally target the viral receptor binding protein, such as the VP2 of bluetongue virus (BTV). This pressure from the immune system can drive mutation of the viral protein resulting in escape from antibody-mediated neutralization and the evolution of serotypes, as is the case for BTV. Understanding the structural differences, which underpin the different BTV serotypes, could help guide the design of a BTV vaccine that targets multiple serotypes. In this study, we have mapped the VP2 structural differences between distant serotypes, to a region targeted by neutralizing antibodies, and have demonstrated for the first time how VP2 structure is the fundamental basis of serotype specificity.

Sudden death due to aortic rupture in New Zealand sheep

ABSTRACT Case history Over a period of 2 months in the spring and early summer of 2021, 13 cases of sudden death in cull ewes due to aortic rupture were diagnosed at a small number of New Zealand abattoirs. Clinical findings In 12/13 (92%) cases, a large blood clot was present in the thorax, and in one case the blood clot was seen in the tissues dorsal to the heart. There were no obvious signs of external trauma. The pluck (heart and lungs) or fixed aorta was submitted for histological examination in seven cases and in all of these, a tear in the aorta was found. Comparing the microscopic appearance of the proximal aorta in these seven cases to three clinically normal ewes from unaffected farms, the aortic wall thickness appeared thinner in the case ewes than the unaffected ewes. Subjectively, there was increased collagen in the tunica media in 3/7 and decreased elastin fibres in 5/7 case ewes compared to the control ewes. Further investigations on the index farm (where the first cases originated), found that the mean liver and serum Cu concentrations in 10 similarly aged, clinically normal ewes were within the normal reference range for New Zealand sheep. Similarly, the liver Cu concentrations of the seven case ewes were within the normal reference range. Diagnosis Aortic rupture due to an unknown aetiology. Clinical relevance Clinicians should be aware of this condition as a differential diagnosis for sudden death in older sheep and to assist the Ministry for Primary Industries in establishing the extent of this problem in New Zealand.

Update on liver fluke in sheep and cattle

Fasciola hepatica, the common liver fluke, affects the health and welfare of grazing animals worldwide. Liver fluke infection has a significant economic cost to the UK agriculture industry through sheep deaths, reduced growth rates, fertility and milk production in sheep and cattle and condemned livers at the abattoir. Changing weather patterns in the UK over recent years have often resulted in milder winters and summers that may be hot or wet but are above all unpredictable, affecting the epidemiology of liver fluke. This poses a risk for farmers relying on traditional calendar-based treatment routines, who may be caught out by liver fluke risk periods that are longer and extend beyond what would traditionally have been expected. Triclabendazole resistance is an increasing problem in many parts of the country and with no new flukicides on the horizon, existing products need to be used responsibly to ensure they remain useful for as long as possible.

Discovery and characterization of BRBV-sheep virus in nasal swabs from domestic sheep in China.

The escalating occurrence of infectious disease outbreaks in humans and animals necessitates innovative, effective, and integrated research to better comprehend their transmission and dynamics. Viral infection in livestock has led to profound economic losses globally. Pneumonia is the prevalent cause of death in sheep. However, very few studies exist regarding virus-related pathogens in sheep. Metagenomics sequencing technologies in livestock research hold significant potential to elucidate these contingencies and enhance our understanding. Therefore, this study aims to characterize respiratory viromes in paired nasal swabs from Inner Mongolian feedlot sheep in China using metaviromic sequencing. Through deep sequencing, de novo assembly, and similarity searches using translated protein sequences, several previously uncharacterized and known viruses were identified in this study. Among these discoveries, a novel Bovine Rhinitis B Virus (BRBV) (BRBV-sheep) strain was serendipitously detected in the nasal swabs of domestic sheep (Ovis aries). To facilitate further molecular epidemiological studies, the entire genome of BRBV-sheep was also determined. Owing to the unique sequence characteristics and phylogenetic position of BRBV-sheep, genetically distinct lineages of BRBV in sheep may exist. A TaqMan-based qRT-PCR assay targeting the 3D polymerase gene was developed and used to screen 592 clinical sheep specimens. The results showed that 44.59% of the samples (264/592) were positive. These findings suggest that BRBV sheep are widespread among Inner Mongolian herds. This discovery marks the initial identification of BRBV in sheep within Inner Mongolia, China. These findings contribute to our understanding of the epidemiology and genetic evolution of BRBV. Recognizing the presence of BRBV in sheep informs strategies for disease management and surveillance and the potential development of targeted interventions to control its spread.

Оценка биологического действия комбинированного облучения овец для определения «безопасных» уровней радиационного воздействия

After a ground-based nuclear explosion, a large amount of fused melted radioactive particles (MRP) is formed. Entering the body of pasture animals with food, they accumulate in the proventriculus and abomasum, irradiating them against the background of total radiation exposure in sublethal doses. Research on combined irradiation of sheep (MRP+1.6 Gy) was carried out under the guidance of Professor B.N. Annenkov in 1978 on 48 sheep irradiated at a dose of 1.6 Gy in combination with feeding sheep with ORF activity from 9.99 to 51.80 MBq/kg of live weight. One group of animals served as non-irradiated controls. In addition, the work used experimental data obtained on 10 sheep irradiated at a dose of 2 Gy. Experimental data were analyzed using mathematical statistics methods. Combined irradiation is accompanied by moderate leukopenia, increased blood viscosity and damage to the gastrointestinal tract. Changes in the gastrointestinal tract are characterized by atony of the proventriculus, pain in the area of the xiphoid cartilage (mesh) and abomasum, hemorrhages and ulcers on the mucous membranes, as well as a decrease in the consumption of feed and water, which led to loss of live weight and death of animals. A study of the dynamics of death of irradiated sheep (probit analysis) showed that the minimum values of death (1 and 5%) can be caused by the consumption of MRP + 1.6 Gy with activity from 4.07 to 6.57 MBq/kg of live weight. Similar data were obtained when analyzing the values of ruminal motility (rumination) in irradiated sheep (3.6 and 5.4 MBq/kg live weight). Therefore, the “safe” level of ORS activity can reach 6.6 MBq/kg live weight of sheep +1.6 Gy of total irradiation.

Analysis of histopathology and changes of major cytokines in the lesions caused by Mycoplasma ovipneumoniae infection

BackgroundMycoplasma ovipneumoniae (M. ovipneumoniae) is one of the main pathogens of sheep pneumonia, causing a series of clinical symptoms, such as depression, anorexia, hyperthermia, cough, dyspnea, and tract secretions. In recent years, the prevalence of M. ovipneumoniae pneumonia has become increasingly serious in sheep farms in Ningxia, China, leading to the death of sheep, and causing significant economic losses. In this study, the pathological organs infected by M. ovipneumoniae were collected to observe histopathological change, to determine the tissue localization of M. ovipneumoniae, and to analyze the cytokine changes, which lays a basis for the diagnosis and pathogenesis of M. ovipneumoniae disease.ResultsIn this study, M. ovipneumoniae was detected in 97 of 105 samples collected from 13 large-scale sheep farms for nucleic acid by PCR. One representative isolate per farm was isolated from 13 farms. The lesions caused by M. ovipneumoniae were mainly in the trachea, bronchus, and lung, including necrosis of tracheal mucosal epithelial cells, disintegration of some epithelial cells, edema of mucosal lamina propria, with inflammatory cell infiltration, cytoplasmic vacuolization of epithelial cells of bronchial mucosa, massive infiltration of inflammatory cells in the alveolar space of lung, necrosis and hyperplasia of alveolar epithelial cells. Immunohistochemical analysis showed that the proportion of M. ovipneumoniae positive area in the lung was the largest, followed by that in the bronchus and trachea. Compared to healthy animals, diseased animals exhibited up-regulated gene expression levels of IL-1β, IL-6, and NF-κB in the trachea, bronchus, and lungs. In contrast, the expression of IL-10, IL-12, and IFN-γ was primarily limited to the trachea and bronchus. The expression of IL-1β showed differential patterns across different lung regions, with variations observed among lung lobes. Additionally, other cytokines consistently showed significant up-regulation specifically in the bronchus.ConclusionsM. ovipneumoniae is primarily found in the lungs of infected individuals. NF-κB, an essential transcription factor, is involved in the regulation of IL-1β transcription. IL-12 may enhance the cytotoxic function of natural killer cells during M. ovipneumoniae infection. Those findings demonstrate the distinct expression profiles of cytokines in various anatomical sites throughout disease progression, suggesting the potential role of bronchial tissue as a major site of immune response.

Experiments on physical ablation of long bone using microwave ablation; defining optimal settings using ex- and in-vivo experiments.

Improved survival of cancer patients leads to more skeletal metastatic lesions that need local therapies for tumor control and pain relief. Not all tumors are radiosensitive and alternative therapies are direly needed. Microwave ablation (MWA) is a technique for minimally invasive local tumor control by physical ablation. In soft tissue local temperature ablation is more common, but studies on bone tissue are limited. To ensure safe and effective treatment, studies on local tumor ablation in bone are needed. Microwave ablation was performed on sheep bone, for both in- and ex-vivo settings. Both a slow-cooking MWA protocol (gradually increasing wattage in the first two minutes of ablation) and a fast-cooking protocol (no warm-up period) were used. Heat distribution through the bone during ablation was determined by measuring temperature at 10- and 15mm from the ablation probe (= needle). Ablation size after procedure was measured using nitro-BT staining. In-vivo ablations led to up to six times larger halos than ex-vivo with the same settings. Within both ex- and in-vivo experiments, no differences in halo size or temperature were found for different wattage levels (65W vs 80W). Compared to a fast cooking protocol, a two-minute slow cooking protocol led to increased temperatures and larger halos. Temperatures at 10- and 15mm distance from the needle no longer increased after six minutes. Halo sizes kept increasing over time without an evident plateau. Microwave ablation is technically effective for creating cell death in (sheep) long bone. It is recommended to start ablations with a slow-cooking period, gradually increasing the surrounding tissue temperature in two minutes from 40 to 90°C. Ex-vivo results cannot simply be translated to in-vivo.

A Time to Sow, a Time to Reap: Modifications to Biological and Economic Rhythms in Southwest Asian Plant and Animal Domestication

This paper reviews changes to lifecycle temporality in Southwest Asian plant and animal domestication, exploring their relationship to long-term processes associated with ancient and contemporary globalization. We survey changes under domestication to the timing of seed dispersal, germination, vegetative growth, flowering and maturation in wheat and barley and to birth, reproduction, lactation, wool production and death in sheep, goats and cattle. Changes in biological temporality among domesticates are ultimately related to globally increasing production intensity, geographic diffusion, and agricultural diversity associated with cultivar/breed evolution. Recently, however, increasing crop production intensity and geographic diffusion are accompanied by declining agricultural diversity worldwide. Similar processes are apparent in contemporary economic and cultural globalization, suggesting that long-term agricultural developments might be viewed as a subset of globalization. Moreover, the origin of certain features of contemporary globalization may be traced back to the beginnings of plant and animal domestication. Thus, while biologists since Darwin considered domestication as a model for the study of evolution, we suggest that domestication may also offer a model for the study of globalization.

Eugenia pyriformis ('uvaia') intoxication of sheep / Intoxicação por Eugenia pyriformis ('uvaia') em ovinos

This study describes the clinical and pathological picture of a disease followed by death in sheep raised for subsistence, characterized by difficulty in locomotion, sternal decubitus, severe dyspnea, opisthotonos, and pedaling movements, followed by death. The disease occurred in February 2020 in the northern state of Rio Grande do Sul, Brazil, due to the consumption of the fruits of Eugenia pyriformis ('uvaia'). All sheep that became ill later died, resulting in morbidity of 68.75% and mortality of 100%. An autopsy revealed the presence of E. pyriformis fruits with or without seeds in the rumen, in addition to the diet provided to the animals. The main histological findings consisted of edema and perivascular cuffs in the frontal telencephalon, nephrosis and glomerular necrosis, in addition to glomerulosclerosis. One sheep had heightened urea and creatinine and lower levels of non-protein thiols. Deaths ceased once animals were prevented from accessing E. pyriformis. These findings confirm that this plant was responsible for the deaths of the animals and point to the possibility of E. pyriformis having neurotoxic and nephrotoxic action on sheep.

Do anthropogenic sources of food increase livestock predation in the area surrounding Ruaha National Park?

SummaryWild carnivores are threatened by human activities, particularly by lethal responses to livestock predation. As natural prey populations decline, predation of livestock and consumption of discarded livestock ‘waste’ (carcasses and body parts) should increase. We investigated whether parameters linked to the production of livestock waste affected the likelihood of livestock predation. We interviewed 160 households near Ruaha National Park in Tanzania to obtain information on households, livestock ownership, predation and parameters linked to livestock waste production. Our analysis identified parameters that affected the likelihood of predation on cattle, sheep and goats. When these parameters were controlled for, we found an increased likelihood of cattle predation as waste from diseased and slaughtered cattle increased. Sheep predation was more likely and cattle predation was less likely as sheep deaths from starvation increased. Goat predation was more likely in medium-sized than smaller or larger villages, suggesting a trade-off to predators between the increasing benefit of more livestock waste and the costs of higher human disturbance and diminishing natural prey abundance as village size category increased. Our findings suggest that improved disposal of livestock waste from slaughtered cattle and measures to decrease cattle deaths from disease should reduce predation of highly prized cattle.

Risk factors influencing the occurrence of anthrax outbreaks at the Livestock-Game interface in Katunguru, Rubirizi district, Uganda

Anthrax outbreaks are very frequent and recurrent in the Rubirizi district in landing sites along the Kazinga channel in the Queen Elizabeth National Park in Uganda. This has persistently caused huge losses of domestic and wild animals and increased public health risks to communities. A participatory disease search (PDS) was thus conducted to identify risk factors that influence the recurrent occurrence of the outbreaks. Using PDS tools, including, Focus group discussion, Mapping, Seasonal calendars, Timelines and Pairwise ranking, local communities were engaged to recall detailed information regarding previous anthrax outbreaks. The number of persons that participated in focus group discussions ranged from 16 in Kazinga landing site to 22 in Katunguru, 18 in Kashaka landing site and 20 in Kishenyi landing site The findings revealed anthrax outbreaks had been reported previously in Katunguru, Kyabakara, Katera, Kingu and Ryeyu sub-counties of Rubirizi district that lie within or adjacent to the Queen Elizabeth National Park. The last anthrax outbreak occurred in 2014. Death of goats and sheep and wild animals, especially, hippopotami was reported in the landing sites of Kazinga, Katunguru, Kishenyi and Kashaka in Katunguru Subcounty. Uganda Wildlife Authority (UWA) established burial sites for carcasses of dead hippopotami in Kazinga and Kishenyi landing sites. Key risk factors associated with anthrax outbreaks (see attached ranks) in Rubirizi district included: (1) Frequent droughts and associated floods (2.5); (2) Dwelling in landing sites normally used as burial areas for carcasses of dead animals by Uganda Wildlife Authority (2.8); (3) Free movement of goats and sheep and intermingling with wildlife at landing sites along Kazinga channel (3.0); (4) Community habit of eating the meat of dead wild or domestic animals (3.8); (5) Communities eating not well-cooked meat (4.0); (6) Ignorance among communities regarding anthrax and its mode of spread (4.8); (7) Frequent migration of communities from landing sites with low to those with a high risk of anthrax disease (6.5); (8) Grazing domestic animals in close proximity with wildlife in the Game Park (6.8); (9) Communities consuming game meat (8.0); and (10) Frequent occurrence of anthrax outbreaks and spread of anthrax spores through floods and existing water bodies (8.3). In conclusion, the PDS case study successfully identified risk factors associated with anthrax outbreaks in Katunguru Subcounty of Rubirizi district in Uganda. Sensitization of communities on anthrax, its mode of spread and effective and sustainable control was recommended in order to contain anthrax outbreaks.

Causas de morte e condenação de órgãos no abate de ovinos em sistema de confinamento no Sul do Rio Grande do Sul

ABSTRACT: In Brazil the second largest sheep herd is in Rio Grande do Sul and in recent years the demand for meat consumption of this specie has increased. Intensive farming systems have made considerable progress in this region with the objective of increasing the production of sheep for slaughter and obtaining a uniform batch to ensure better quality of sheep meat to consumers. However, the agglomeration and stress that animals go through can lead to the occurrence of illnesses and economic loss to producers. The objectives of this paper were to determine the main causes of death that affected sheep in a feedlot system, to establish forms of control and prophylaxis of diagnosed illnesses, and to estimate the economic losses resulting from them. The objective was also to determine the causes of condemnation of organs or carcasses in the slaughterhouses that processed the sheep were sent, and to estimate the losses in this productive sector. For this, a follow-up work was carried out in an establishment located in the city of São Lourenço do Sul, Rio Grande do Sul, from October 2020 to September 2021. The dead sheep at the feedlot were necropsied, and the diagnosis was made based on clinical signs, pathology, and bacteriology. The main diseases diagnosed were parasitic enteritis (15.4%), pneumonia (13%), and listeriosis (9.6%). In the slaughterhouse study, the lesions that led to the highest number of condemnations were hydatidosis (29.9%), renal congestion (26.2%), and renal ischemia (25.8%). The economic losses estimated for the death of sheep in 2021 was R$17,480.00, significantly lower than the approximate losses in 2019 and 2020 of R$50,000.00 and R$54,000.00, respectively. This highlights the importance of technical assistance to reduce these losses due to mortality in sheep raised in a feedlot system. It was also observed the kidneys of the sheep were the organs most frequently selected for condemnation. The economic value of the kidneys sold as disposed waste was eight time lower than that the value of kidneys suitable for consumption.

Oak leaf (Quercus spp.) intoxication in a sheep

A twenty-year-old ewe presented with acute lateral decubitus, tremor and dyspnea, followed by death. Post-mortem examination revealed a large amount of oak leaves in the rumen, reticulum and omasum. The duodenum had a focal hemorrhagic content and multifocal hemorrhages were present in several organs. Histopathological examination of the kidneys showed characteristic lesions of oak intoxication, such as intratubular hemorrhage, tubular degeneration and necrosis. This case report illustrates the importance to include oak intoxication in the differential diagnosis of acute death in sheep and the value of post-mortem and histopathological examination.

Патогенетичні та патоморфологічні аспекти непрохідності шлунково-кишкового тракту дрібної рогатої худоби

The aim of the work was to compare pathomorphological changes and death mechanisms in cases of cattle deaths with different etiologies dystonia, to determine the causes of death depending on the genesis of the disease and to establish informative criteria for pathomorphological diagnostics. A study of the sheep death as a result of mechanical obstruction and, accordingly, the inability to release the masses from the mesh due to eating a rubber glove. The animal developed chronic bloating, which led to a long-term violation of the motor skills of the pre-ventricle and the formation of phytoconcrements identical in morphology to the feed masses. Studies have found that the normal motor skills violation of the pre-ventricles of ruminants in the vast majority of cases is caused by the human factor. The development of dystonia is often associated with mechanical obstruction, which is a primary nature and is a consequence of flatulence (air stasis), the phytoconcrements formation or the presence of other foreign bodies in the lumen. Pathognomonic signs of the pre-ventricle dystonia are abdominal organs and abdominal muscles anemia, the chest and neck muscles venous hyperemia, compression atelectasis and the diaphragmatic parts of the lungs anemia, the middle and cranial parts of the lungs edema and venous hyperemia. For periodic chronical bloating and the pre-ventricle blockage, mucosal necrosis areas, the phytoconcrements formation, and brown lung induration are characteristic features. The immediate cause of the pre-ventricles dystonia death is asphyxiation, pulmonary edema or paralysis of the respiratory center with venous hyperemia and brain edema, poisoning with the contents of the gastrointestinal canal result. The animal usually dies within the first 12 hours of the onset of the disease.

CAUSES OF MORTALITY OF SHEEP IN IBADAN, NIGERIA: A CASE STUDY OF SHEEP AND GOAT UNIT OF IBADAN DAIRY FARM

This study was carried out in an attempt to determine the causes of mortality in sheep in Ibadan, Southwest Nigeria. The result showed the most common causes of mortality were pneumonia (19.5%), diarrhoea (18.5%) lielminthiasis (17.0%), starvation (9.5%) and Animals enterotoxaemia (8.7%). 65.7% of all the 811 deaths recorded occurred during the first six months of life indicating that lambs were more susceptible to infections than adult sheep deaths occurred among the females than male sheep. Most deaths occurred during the dry. season months of December to February. It seemed that the constraint on sheep productivity imposed by disease can be greatly ameliorated by a combination of improvement of dry season feeding and the prevention of the three major diseases that were together responsible for 55% of all deaths.

Causes of death in sheep in Rio Grande do Sul, Brazil: analysis of 523 cases (2004-2019)

ABSTRACT: The increase in the commercialization of sheep products requires an equivalent improvement in flock health and rapid disease identification. Data regarding the cause of death in sheep were reviewed from the database of the “Setor de Patologia Veterinária” from the “Universidade Federal do Rio Grande do Sul”, from January 2004 and December 2019. Epidemiological features, such as breed, sex, and age, in addition to the clinical and pathological features, were analyzed. During this period, tissues from 523 sheep were evaluated, in which a conclusive diagnosis was obtained in 457 (87%) of the cases. The majority of sheep were from the metropolitan mesoregion of Porto Alegre. The most common breed was Texel 171/523 (33%). From all the conclusive diagnoses, 158/457 (35%) corresponded to infectious non-parasitic diseases, 117/457 (26%) were caused by toxic etiology, 95/457 (21%) were infectious parasitic diseases, 42/457 (9%) were included in the nutritional and metabolic category, 38/457 (8%) were in the “others” category, and 7/457 (1.5%) were congenital defects. The age of sheep included in this study ranged from 1 day to 7 years. Among cases with conclusive diagnosis, the main cause of death was haemonchosis with 83/457 (18%) of cases, followed by pneumonia 29/457 (6%), Baccharis sp. poisoning 25/457 (5%), and bluetongue 22/457 (5%).

Nitrate-nitrite toxicosis associated with duckweed (Portulaca Oleracea L.) (Portulacaceae) consumption in a herd of sheep in Kenya

Background: Nitrate-nitrite toxicosis associated with the consumption of duckweed (Portulaca oleracea L.) (Portulacaceae) was diagnosed in a small herd comprising of 11 sheep in Korayo Sub Location, Rangwe Sub County of Homabay County in Kenya. Methods: The clinical signs were dyspnea, froth from the mouth, labored breathing, incoordination, tachycardia, increased urination, neck, fore and hind limb distension, aggressive movements, bloat, convulsions, and coma, before death. Results: All the 11 sheep died of intoxication before institution of therapy. Brownish mucous membranes and chocolate colored and poorly clotted blood were the significant necropsy observations. Mild pulmonary edema was characterized by the presence of limited froth in the trachea and bronchioles. At postmortem, the liver of the sheep was grossly congested, and the cardiac pericardium was inflamed. There was gastritis, enlarged, and congested kidneys with pin-point hemorrhages. Diphenylamine tests carried out on the fed duckweed and on ruminal duckweed contents were positive for nitrates. Duckweed (Portulaca oleracea) fed on sheep had 7.4% nitrate on dry matter basis (DM), whereas ruminal contents had 5.38% nitrate on DM basis. Chocolate-colored blood collected during postmortem had a methemoglobin fraction of 86%. Nitrate levels in pastures of 0.5% and above have been shown to be potentially dangerous, with acute poisoning likely to occur at times when the levels are above 1%. Death in sheep can occur when blood methemoglobin levels are in the range of 67%–90%. Conclusion: The observations from the present study are indicative of death in a herd of sheep due to nitrate-nitrite poisoning associated with the consumption of duckweed (Portulaca oleracea).

Neospora caninum and Toxoplasma gondii as causes of reproductive losses in commercial sheep flocks from Argentina

The aim of this study is to provide preliminary data about the occurrence of Neospora caninum- and Toxoplasma gondii-related abortions and perinatal deaths in sheep from Argentina. Thirty ovine aborted foetuses and 33 perinatal deaths were submitted to the Veterinary Diagnostic Service at INTA EEA Balcarce (Argentina) during 2017–2019. A complete necropsy was performed on all specimens submitted, and foetal and placental tissues were examined. Foetal cavity fluids were collected for assessment of antibodies to N. caninum and T. gondii by indirect fluorescent antibody technique (IFAT). Placental and foetal tissue samples were collected for DNA extraction and histopathological analysis. The differential diagnosis with other causes of abortion was carried out. Of the sampled specimens, 20.63% (13/63) displayed evidence for N. caninum infection by IFAT and PCR, and in 61.5% (8/13) of the positive specimens the parasite was confirmed as the cause of abortion/perinatal death based on the presence of compatible histological lesions and/or positive immunohistochemistry test, positive PCR and/or positive IFAT, and no other infectious agents diagnosed. In contrast, T. gondii infection was confirmed in 9.52% (6/63) of the analysed specimens, but only in 2 lambs T. gondii was determined as the death cause. Neosporacaninum and T. gondii co-infections were confirmed in 4 analysed specimens (2 aborted foetuses and 2 perinatal deaths). These results demonstrated that N. caninum is efficiently transmitted and a frequent cause of ovine reproductive failure in the commercial analysed flocks compared with T. gondii. Despite T. gondii congenital infection was detected in some specimens (6/63), it was confirmed as the cause of death in only two of them. Thus, and considering the limited availability of confirmed samples, we could not determine whether toxoplasmosis is a major problem in Argentinian sheep flocks or not. More studies on a greater number of specimens from different ovine production systems under different management conditions are necessary to assess the real impact of neosporosis and toxoplasmosis in Argentina.

Diet changes lead to ruminal acidosis and death in Scottish cattle and sheep.

Diet changes lead to ruminal acidosis and death in Scottish cattle and sheep.

Mixed course of Fasciolosis and Paramphistomatosis in sheep in Uzbekistan

The purpose of the research to study the mixed course of sheep infection, caused by pathogens of fasciolosis and paraphistomatosis, in the conditions of Samarkand and Tashkent regions. Materials and methods. The research material was fallen and forcibly killed sheep from two regions of Uzbekistan, simultaneously infected by Fasciola gigantica and Paramphistomum spp. (Gastrothylax crumenifer, Calicophoron calicophorum). The animals' liver was subjected to complete helminthological dissection, followed by the presence of young immature in the parenchyma, and in the bile ducts – sexually mature fasciola. To detect pathogens of paramphistomatosis, we examined the scar and mesh, and, if necessary, the mucous membranes of the abomasum and the initial part of the small intestine. To kill the collected F. gigantica and complete bleeding with a Paramphistomum spp., they were kept in water for one and three to four days, respectively. After they took their natural form, their type, age and number were determined, and then fixed in Barbagallo fluid. If necessary, coprological studies of sheep and malacological studies of biotopes of freshwater mollusks, intermediate hosts of the studied trematodes, were carried out. Results and discussion. In recent years, cases of a mixed course in sheep fasciolosis (F. gigantica) and paramphistomatosis in farms of Uzbekistan have become more frequent. When opening the liver of the fallen sheep, up to 278 specimens were found immature F. gigantica and up to 3994 sp. G. crumenifer. In some farms, the death of individual owners' sheep from calicophorosis caused by C. calicophorum was observed with an intensity of infection of 592 sp. of C. calicophorum.