Infectious sporadic bovine abortions: retrospective analysis.

Infectious sporadic abortions in cattle are mainly caused by opportunistic bacteria and fungi usually present in environmental or gastrointestinal and reproductive microbiota of healthy animals. A retrospective analysis was carried out to evaluate the main opportunistic microorganisms involved in bovine abortions recorded at INTA Balcarce (Argentina) from 1997 to 2023, accounting for 2.2% of the total diagnosed etiologies of bovine abortion. The opportunistic agents identified as the cause of abortion in 29 fetuses were bacteria (90%) and fungi (10%). Escherichia coli (n = 8), Trueperella pyogenes (n = 5), and Histophilus somni (n = 4) were the bacterial species most often identified as causing infectious abortions, whereas Aspergillus spp. (n = 3) was implicated in all fungal abortions identified. Pure culture of bacteria or fungus was achieved from abomasal content and/or lung essential. Main microscopic findings were bronchopneumonia, myo- and epicarditis, meningitis, and portal hepatitis. Herein, we highlight the importance of detecting potential infectious bacteria in cultures to improve etiological diagnosis of bovine abortions associated with compatible microscopic findings to confirm the etiology.

Solanum glaucophyllum intoxication in goats: Case study.

Solanum glaucophyllum is a toxic plant with calcinogenic effect that causes enzootic calcinosis (EC) characterized by soft tissue metastatic mineralization mainly in cattle and rarely sheep, buffaloes, pigs, horses, and goats. We describe an outbreak of EC in a herd of 64 goats due to S. glaucophyllum consumption. Thirty-four goats were affected exhibiting hirsutism, stiffening, kyphosis and emaciation. Twelve goats died. Grossly, tissue mineralization was observed in the aorta and carotid arteries, lungs, and heart. Lesions were characterized by multiple rough white plaques, and hardened tissues with loss of elasticity. Microscopically, multisystemic mineralization was observed in aorta and carotid arteries, heart, lung, abomasum, intestine, spleen, lymph nodes, kidney, spleen, and meninges, characterized by extensive granular basophilic deposits of tunica media and/or intima of blood vessels; confirmed as calcium salt deposits with Von Kossa stain. We conclude that ingestion of S. glaucophyllum can cause EC in goats. Though EC is rare in goats under some conditions such as heavy drought and abundant S. glaucophyllum exposure disease can develop.

Salmonellosis in adult cattle in Central Argentina: case series.

Salmonellosis is an infectious disease caused by bacteria belonging to the Salmonella genus. Bovine salmonellosis is more frequent in young cattle under intensive overcrowd husbandry conditions, and therefore uncommon in adults. We report four outbreaks of clinical salmonellosis due to Salmonella Typhimurium, Salmonella Newport and Salmonella Dublin provoking outbreaks of diarrheic/septicemic disease in adult cattle of Central Argentina. Anamnesis information, clinical, pathological, and bacteriological findings were retrospective analyzed. This report emphasizes the importance to include salmonellosis among the differential diagnosis of clinical enteric/septicemic disease in adult cattle under different husbandry conditions in Argentina. The source of Salmonella could not be established in these outbreaks.

Evaluation of species-specific polyclonal antibodies to detect and differentiate between Neospora caninum and Toxoplasma gondii.

Neosporosis and toxoplasmosis are major causes of abortion in livestock worldwide, leading to substantial economic losses. Detection tools are fundamental to the diagnosis and management of those diseases. Current immunohistochemistry (IHC) tests, using sera raised against whole parasite lysates, have not been able to distinguish between Toxoplasma gondii and Neospora caninum. We used T. gondii and N. caninum recombinant proteins, expressed in Escherichia coli and purified using insoluble conditions, to produce specific polyclonal rabbit antisera. We aimed to develop species-specific sera that could be used in IHC on formalin-fixed, paraffin-embedded (FFPE) tissue sections to improve the diagnosis of ruminant abortions caused by protozoa. Two polyclonal rabbit sera, raised against recombinant proteins, anti-Neospora-rNcSRS2 and anti-Toxoplasma-rTgSRS2, had specificity for the parasite they were raised against. We tested the specificity for each polyclonal serum using FFPE tissue sections known to be infected with T. gondii and N. caninum. The anti-Neospora-rNcSRS2 serum labeled specifically only N. caninum-infected tissue blocks, and the anti-Toxoplasma-rTgSRS2 serum was specific to only T. gondii-infected tissues. Moreover, tissues from 52 cattle and 19 sheep previously diagnosed by lesion profiles were tested using IHC with our polyclonal sera and PCR. The overall agreement between IHC and PCR was 90.1% for both polyclonal anti-rNcSRS2 and anti-rTgSRS2 sera. The polyclonal antisera were specific and allowed visual confirmation of protozoan parasites by IHC, but they were not as sensitive as PCR testing.

Acute atrazine intoxication in heifers: Case report and toxicological studies.

Atrazine is a triazine organochloride herbicide, frequently used in different agricultural activities. Rare acute intoxication with atrazine is reported in production animals, and its metabolism in mammals is unknown. We report a spontaneous case of atrazine acute intoxication in 16.1% animals of a 168-beef heifer herd exposed to the herbicide at a farm located in Buenos Aires province, Argentina. Affected heifers showed different neurological signs and died suddenly, similar to the previous natural atrazine intoxication report. During autopsy, no gross lesions were observed. Different body fluids and tissues samples were collected during postmortem examination. No relevant histopathological findings were observed. High levels of atrazine and its metabolites were detected in different fluids and tissues by ultra-liquid chromatography high performance coupled to triple quadrupole mass spectrometry. These findings suggest ruminal or hepatic metabolization of atrazine in the exposed cattle. This is the first report of quantification and distribution of atrazine and its metabolites in intoxicated mammals providing relevant information for diagnostic purposes.

Identification and molecular characterization of Orfvirus infection in occupationally exposed women inSouth America

Abstract Contagious Ecthyma (CE) is a severe exanthematous dermatitis caused by the Orf virus (ORFV) that mainly affects domestic small ruminants such as sheep and goats. It is a worldwide-distributed occupational zoonosis, particularly infecting those in close contact with animals or animal products such as shepherds, farmers and veterinarians, among others. In the present work, we report the first human CE case confirmed in Argentina. A phylogenetic analysis based on four gene sequences of the isolated strain responsible for the disease showed that this isolate grouped with other ORFV sequences that caused reported CE cases in sheep from the same Argentine province. We also sequenced a sample from a Chilean human case reported in 2017, whose phylogenetic analysis showed that it groups together with other Argentine isolates from locations close to the border with Chile. Keywords: Contagious Ecthyma; Dermatitis; Human Orf; Zoonosis; Molecular characterization.

Resumen El ectima contagioso (EC) es una dermatitis exantemática grave causada por el virus Orf (ORFV), que afecta mayormente a pequeños rumiantes domésticos, como ovinos y caprinos. Es una zoonosis ocupacional con distribución mundial, infecta a humanos en estrecho contacto con animales o sus productos, como granjeros, esquiladores y veterinarios, entre otros. En este trabajo se informa el primer caso humano de EC confirmado en Argentina. Un análisis filogenético basado en cuatro genes de la cepa responsable de este caso mostró que el aislamiento agrupa con otras secuencias de ORFV que causaron casos en ovinos en la misma provincia argentina. También se secuenció una muestra del caso de ectima humano reportado en Chile en 2017 y el análisis filogenético mostró que dicho aislamiento forma un grupo con otros aislamientos argentinos de localidades cercanas a la frontera con Chile. Palabras clave: Ectima contagioso; Dermatitis; Orf en humanos; Zoonosis; Caracterización molecular.

Hypomagnesemia in beef cattle from the central region of Argentina: retrospective study / Hipomagnesemia em bovinos de corte da região central da Argentina: estudo retrospectivo

Hypomagnesaemia (grass tetany) is a metabolic disorder of ruminants due to a reduced dietary intake of magnesium (primary deficiency), incorrect digestibility or associated metabolic factors reducing Mg intake (secondary deficiency). Grass tetany is a production disease responsible for important economic losses in beef herds from Argentina. Several factors influence the development of grass tetany in cattle, including physiological status, weather, soil and forage. This research described a retrospective analysis over the past 20 years, revising the cases of beef cattle clinical hypomagnesaemia registered at the Veterinary Diagnostic Service in INTA Balcarce, Argentina.

Hipomagnesemia é um distúrbio metabólico de ruminantes devido a uma redução na absorção de magnésio (deficiência primária), digestibilidade incorreta ou fatores metabólicos associados que reduzem a ingestão de Mg (deficiência secundária). Hipomagnesemia é uma doença de produção responsável por importantes perdas econômicas em rebanhos de corte da Argentina. Vários fatores influenciam o desenvolvimento da hipomagnesemia em bovinos, incluindo fatores fisiológicos, clima, solo e forragem. Este trabalho descreve uma análise retrospectiva dos últimos 20 anos, revisando os casos de hipomagnesemia clínica em bovinos de corte registrados no Serviço de Diagnóstico Veterinário do INTA Balcarce, Argentina.

Mycoplasma bovis-pneumonia and polyarthritis in feedlot calves in Argentina: First local isolation / Neumonía y poliartritis por Mycoplasma bovis en terneros de feedlot: primeraislamiento local

Abstract Bovine respiratory disease (BRD) is one of the most frequent clinical concerns inweaned calves after their arrival at the feedlot. This work reports the first local isolation ofMycoplasma bovis from feedlot calves with pneumonia and polyarthritis in Argentina. Twentyfour out of 545 calves showed progressive, subacute to chronic respiratory distress, coughing,and fever. Thirty percent of the affected calves also showed lameness and swelling of elbowor carpal, and knee or tarsal joints. Five necropsies were performed and severe multifocal tocoalescent pulmonary nodules, containing white-yellowish caseous exudate encircled by fibroustissue, and fibrinonecrotic arthritis and tenosynovitis were detected. Mycoplasma was isolatedfrom lung and joint samples. The 16S-23S rRNA ITS consensus sequence obtained from theseisolates showed 100% similarity with the same region of M. bovis strains. Since there are no com-mercially available vaccines in the region for the prevention and control of M. bovis pneumoniaand arthritis, surveillance is a priority to reduce the source of disease to naïve animals.

Resumen La enfermedad respiratoria bovina es uno de los problemas sanitarios más fre-cuentes en terneros recién destetados luego de su arribo a los corrales de encierre (feedlots).Este trabajo describe el primer aislamiento local de Mycoplasma bovis de terneros de feedlotcon neumonía y poliartritis en Argentina. Se vieron afectados 24 de 545 terneros; mostraron enfermedad respiratoria progresiva, subaguda a crónica, tos y fiebre. De los terneros afecta-dos, el 30% presentó, además, problemas en articulaciones carpales o tarsales. Se realizaron5 necropsias de terneros afectados y se observaron nódulos pulmonares multifocales a coa-lescentes, que contenían un exudado caseoso blanco-amarillento, rodeados de tejido fibroso,artritis y tenosinovitis fibrinonecrótica. Se aisló Mycoplasma de muestras de pulmón y artic-ulación. La secuencia consenso del gen codificante del ARNr 16S-23S rRNA obtenido de estosaislamientos mostró un 100% de similitud con la misma región de cepas de M. bovis. Teniendoen cuenta que no hay vacunas disponibles comercialmente en la región para la prevencióny el control de neumonías y poliartritis por M. bovis, es importante realizar una vigilanciaepidemiológica a fin de reducir las fuentes de infección para animales susceptibles.

Spontaneous outbreak of Pascalia glauca poisoning in sheep in Argentina

Pascalia glauca is a native weed and one of the most common hepatotoxic plant affecting cattle in Argentina. Although experimental P. glauca poisoning have been reported in sheep, no spontaneous cases have been reported in this species. This work describes an outbreak of intoxication after spontaneous consumption of P. glauca, affecting 20% (6/30) sheep of a commercial flock. Affected sheep were ataxic, depressive, with mucous nasal discharge, cough and abdominal breathing. During post mortem examination, liver was swollen and a diffuse enhancement of the reticular pattern (“nutmeg liver”) was visible. Histopathological examination reveals severe and extensive acute diffuse centrilobular hepatic necrosis with hemorrhage. The presence of the toxic plant, the clinical and pathological findings allows us to confirm the etiology of this outbreak.(AU)

Spontaneous outbreak of Pascalia glauca poisoning in sheep in Argentina

Pascalia glauca is a native weed and one of the most common hepatotoxic plant affecting cattle in Argentina. Although experimental P. glauca poisoning have been reported in sheep, no spontaneous cases have been reported in this species. This work describes an outbreak of intoxication after spontaneous consumption of P. glauca, affecting 20% (6/30) sheep of a commercial flock. Affected sheep were ataxic, depressive, with mucous nasal discharge, cough and abdominal breathing. During post mortem examination, liver was swollen and a diffuse enhancement of the reticular pattern (“nutmeg liver”) was visible. Histopathological examination reveals severe and extensive acute diffuse centrilobular hepatic necrosis with hemorrhage. The presence of the toxic plant, the clinical and pathological findings allows us to confirm the etiology of this outbreak.

Comparación de ELISAs comerciales para la detección de anticuerpos en la investigación diagnóstica del aborto asociado a Neospora caninum en rodeos lecheros de Uruguay Comparación de ELISAs comerciales para detección de anticuerpos contra N. caninum / A comparative study of commercial ELISAs for antibody detection in the diagnostic investigation of Neospora caninum-associated abortion in dairy cattle herds in Uruguay

Resumen A pesar de su importancia, el diagnóstico etiológico del aborto en bovinos representa un desafío técnico para los veterinarios clínicos y laboratoristas, en parte debido a la dificultad de recuperar los fetos abortados en condiciones extensivas de campo. Dicha dificultad limita la posibilidad de detectar tempranamente los vientres abortados y de efectuar la investigación patológica y microbiológica de los abortos. Neospora caninum es un protozoario cosmopolita identificado como uno de los principales agentes abortigénicos en bovinos. En este estudio proponemos una aproximación seroepidemiológica para diagnosticar abortos por N. caninum en bovinos lecheros usando kits de ELISA comerciales. Se procesaron muestras de entre 12 y 93 vacas y/o vaquillonas con (casos) y sin (controles) historia reciente de aborto en 4 tambos comerciales de Uruguay. La proporción controles:casos analizados varió entre 1:1 y 4,6:1. Las muestras (n=230) fueron analizadas mediante 3 kits comerciales para la detección de anticuerpos IgG anti-N. caninum. En los 4 tambos la proporción de vacas y/o vaquillonas seropositivas por cualquier kit fue significativamente mayor en los casos respecto de los controles (odds ratio=5,13 a 36; p=0,0002 a 0,0485). La concordancia entre los kits varió de débil a fuerte (coeficiente Kappa de Cohen=0,58 a 0,83). Concluimos que, a pesar de la imperfecta concordancia entre estos kits, el empleo de todos ellos permitió arribar a conclusiones similares respecto de la asociación estadísticamente significativa entre seropositividad a N. caninum y aborto, lo que demuestra la utilidad de estos kits para la aproximación diagnóstica del aborto a nivel poblacional en condiciones de campo.

Abstract Bovine abortion causes considerable economic losses to the livestock industry worldwide and is of concern for public health and food safety, given that many abortigenic infectious agents of cattle are zoonotic. Despite its importance, the etiological diagnosis of abortion in cattle is challenging both for veterinary practitioners and laboratory technicians, partly due to the difficulty in recovering aborted fetuses under extensive field conditions for pathological and microbiological diagnostic investigation, and in the early identification of aborted dams. Neospora caninum is a cosmopolitan protozoon identified as one of the main abortigenic agents in cattle worldwide. In this study we propose a comparative seroepidemiological approach for the diagnosis of abortion by N. caninum in dairy cattle. Samples from 12 to 93 cows/heifers with and without recent history of abortion (cases and controls) in four commercial dairy farms were tested. The ratio of controls to cases tested varied from 1:1 to 4.6:1. All samples (n=230) were analyzed by three commercial ELISA kits for the detection of anti-N. caninum antibodies. In all four dairy farms, the proportion of seropositive cows and/or heifers per kit was significantly higher in the cases than in the controls (Odds Ratios=5.13 to 36, p=0.0002 to 0.0485). The agreement among the three kits varied from weak to strong (Cohen´s kappa coefficients=0.58 to 0.83). We conclude that, despite the imperfect agreement between these kits, all of them allowed to arrive at similar conclusions regarding the statistical association between N. caninum seropositivity and abortion, thus representing a useful tool for the diagnostic approach at the population level under field conditions.

Systemic granulomatous disease in dairy cattle from Argentina

An outbreak of systemic granulomatous disease of unknown etiology was diagnosed in a dairy herd from Argentina. Eleven out of 211 cows manifested hyperthermia, depression, alopecia, pruritus, decreased milk production and death in most cases. During necropsy, multifocal petechial hemorrhages in glottis and vulva, white multifocal nodules in the liver and splenomegaly with subcapsular petechial hemorrhages were observed. Both kidneys were diffuse pale and enlarged. Systemic granulomatous hepatitis, myocarditis, pancreatitis and nephritis were observed. Water and food samples tested negative for Arsenic and T2 toxin, respectively. Fusarium equiseti was isolated from alfalfa hay samples. Vicia spp. was not consumed by the affected herd and no other cause of vetch-like disease was registered. Other causes of granulomatous lesions (Mycobacterium spp. and fungal infections) were discarded. The systemic granulomatous disease was suggestive of a type IV hypersensitivity reaction. Although the sensitizing agent was not determined, two components of the ration were suspected: cotton seed and bone ash. Both of them were introduced one month prior to the detection of the first affected cow and the disease resolved since they were removed from the diet.

Rhabdomyolysis in water buffaloes (Bubalus bubalis)

Rhabdomyolysis is a myopathy characterized by severe acute myonecrosis with lysis of muscle cells and extravasation of its content into the bloodstream, causing a secondary renal failure and myoglobinuria. Case-reports have been documented in a wide range of wild or domestic animal species, but to our knowledge, no reports in water buffaloes (Bubalus bubalis) have been done. Three animals had signs of paralysis, muscle tremors and myoglobinuria while others died spontaneously. Samples of blood from affected animals showed increased levels of creatin kinase (CK), potassium (K), aspartate transaminase (AST), and lactate dehydrogenase (LDH). In addition, Selenium (Se) levels of those animals were low. Necropsy findings consisted of severe gelatinous and yellowish edema and pallor of the skeletal muscles of the hind limbs, lumbar, cervical and scapular region. Microscopically, acute and severe segmental monophasic coagulative necrosis of skeletal muscles and acute pigmentary tubular nephrosis was observed. We suspect that selenium deficiency was a predisposing factor of rhabdomyolysis in this particular case.

Rhabdomyolysis in water buffaloes (Bubalus bubalis)

Rhabdomyolysis is a myopathy characterized by severe acute myonecrosis with lysis of muscle cells and extravasation of its content into the bloodstream, causing a secondary renal failure and myoglobinuria. Case-reports have been documented in a wide range of wild or domestic animal species, but to our knowledge, no reports in water buffaloes (Bubalus bubalis) have been done. Three animals had signs of paralysis, muscle tremors and myoglobinuria while others died spontaneously. Samples of blood from affected animals showed increased levels of creatin kinase (CK), potassium (K), aspartate transaminase (AST), and lactate dehydrogenase (LDH). In addition, Selenium (Se) levels of those animals were low. Necropsy findings consisted of severe gelatinous and yellowish edema and pallor of the skeletal muscles of the hind limbs, lumbar, cervical and scapular region. Microscopically, acute and severe segmental monophasic coagulative necrosis of skeletal muscles and acute pigmentary tubular nephrosis was observed. We suspect that selenium deficiency was a predisposing factor of rhabdomyolysis in this particular case.(AU)

Systemic granulomatous disease in dairy cattle from Argentina

An outbreak of systemic granulomatous disease of unknown etiology was diagnosed in a dairy herd from Argentina. Eleven out of 211 cows manifested hyperthermia, depression, alopecia, pruritus, decreased milk production and death in most cases. During necropsy, multifocal petechial hemorrhages in glottis and vulva, white multifocal nodules in the liver and splenomegaly with subcapsular petechial hemorrhages were observed. Both kidneys were diffuse pale and enlarged. Systemic granulomatous hepatitis, myocarditis, pancreatitis and nephritis were observed. Water and food samples tested negative for Arsenic and T2 toxin, respectively. Fusarium equiseti was isolated from alfalfa hay samples. Vicia spp. was not consumed by the affected herd and no other cause of vetch-like disease was registered. Other causes of granulomatous lesions (Mycobacterium spp. and fungal infections) were discarded. The systemic granulomatous disease was suggestive of a type IV hypersensitivity reaction. Although the sensitizing agent was not determined, two components of the ration were suspected: cotton seed and bone ash. Both of them were introduced one month prior to the detection of the first affected cow and the disease resolved since they were removed from the diet.(AU)

Current trends in bovine abortion in Argentina / Tendências atuais do aborto bovino na Argentina

Bovine abortion is an important cause of significant economic losses in beef and dairy herds. This syndrome is usually difficult to diagnose. The aim of this study was to characterize bovine abortion causes in Argentina by standard diagnosis procedures (histology, bacterial and viral isolation) and other diagnostic tests like direct fluorescent antibody test (DFAT), fetal serology, immunohistochemistry (IHC), and PCR, showing their specific advantages and limitations. Necropsies were performed in 150 aborted bovine fetuses submitted to the diagnostic laboratories of Instituto Nacional de Tecnología Agropecuaria (INTA) Balcarce, Argentina. Etiological diagnosis was confirmed in 78 fetuses (52% of the cases). Most causes of abortion were of infectious origin, being Neospora caninum (14.67%), Campylobacter fetus sp. (9.33%), Leptospira spp. (7.33%) and Brucella abortus (6.65%) the main microorganisms identified. Bovine viral diarrhea virus (BVDV) and bovine herpes virus (BHV) were diagnosed in 2 (1.33%) and 3 (2%) cases, respectively. This study showed a better characterization of bovine abortion compared with previous researches done on this topic.(AU)

O aborto bovino é uma causa importante de perdas econômicas significativas em rebanhos bovinos e leiteiros. Esta síndrome é geralmente difícil de diagnosticar. O objetivo deste estudo foi caracterizar o aborto bovino na Argentina por procedimentos diagnósticos de rotina (histologia, isolamento viral e bacteriana) e outros testes diagnósticos como ensaio directo de anticorpos fluorescentes (DFAT), sorologia fetal, imuno-histoquica (IHC), e PCR; mostrando suas vantagens e limitações específicas. As necropsias foram realizadas em 150 fetos bovinos abortados submetidos aos laboratórios de diagnóstico do Instituto Nacional de Tecnologia Agropecuária (INTA) de Balcarce, na Argentina. O diagnóstico etiológico foi confirmado em 78 fetos (52% dos casos). A maioria das causas de aborto foram de origem infecciosa, sendo Neospora caninum (14,67%), Campylobacter fetus sp. (9,33%), Leptospira spp. (7,33%) e Brucella abortus (6,65%) os principais microrganismos identificados. O vírus da diarréia viral bovina (BVDV) e o herpesvírus bovino (BHV) foram diagnosticados em 2 (1,33%) e 3 (2%) casos, respectivamente. Este estudo mostrou uma melhor caracterização do aborto bovino em comparação com pesquisas anteriores feita sobre este tema.(AU)

Current trends in bovine abortion in Argentina / Tendências atuais do aborto bovino na Argentina

Bovine abortion is an important cause of significant economic losses in beef and dairy herds. This syndrome is usually difficult to diagnose. The aim of this study was to characterize bovine abortion causes in Argentina by standard diagnosis procedures (histology, bacterial and viral isolation) and other diagnostic tests like direct fluorescent antibody test (DFAT), fetal serology, immunohistochemistry (IHC), and PCR, showing their specific advantages and limitations. Necropsies were performed in 150 aborted bovine fetuses submitted to the diagnostic laboratories of Instituto Nacional de Tecnología Agropecuaria (INTA) Balcarce, Argentina. Etiological diagnosis was confirmed in 78 fetuses (52% of the cases). Most causes of abortion were of infectious origin, being Neospora caninum (14.67%), Campylobacter fetus sp. (9.33%), Leptospira spp. (7.33%) and Brucella abortus (6.65%) the main microorganisms identified. Bovine viral diarrhea virus (BVDV) and bovine herpes virus (BHV) were diagnosed in 2 (1.33%) and 3 (2%) cases, respectively. This study showed a better characterization of bovine abortion compared with previous researches done on this topic.(AU)

O aborto bovino é uma causa importante de perdas econômicas significativas em rebanhos bovinos e leiteiros. Esta síndrome é geralmente difícil de diagnosticar. O objetivo deste estudo foi caracterizar o aborto bovino na Argentina por procedimentos diagnósticos de rotina (histologia, isolamento viral e bacteriana) e outros testes diagnósticos como ensaio directo de anticorpos fluorescentes (DFAT), sorologia fetal, imuno-histoquica (IHC), e PCR; mostrando suas vantagens e limitações específicas. As necropsias foram realizadas em 150 fetos bovinos abortados submetidos aos laboratórios de diagnóstico do Instituto Nacional de Tecnologia Agropecuária (INTA) de Balcarce, na Argentina. O diagnóstico etiológico foi confirmado em 78 fetos (52% dos casos). A maioria das causas de aborto foram de origem infecciosa, sendo Neospora caninum (14,67%), Campylobacter fetus sp. (9,33%), Leptospira spp. (7,33%) e Brucella abortus (6,65%) os principais microrganismos identificados. O vírus da diarréia viral bovina (BVDV) e o herpesvírus bovino (BHV) foram diagnosticados em 2 (1,33%) e 3 (2%) casos, respectivamente. Este estudo mostrou uma melhor caracterização do aborto bovino em comparação com pesquisas anteriores feita sobre este tema.(AU)

Pathology of cattle experimentally intoxicated with ground Ricinus communis seeds

Five Aberdeen Angus calves were inoculated intra-ruminally with ground seeds of Ricinus communis at doses of 1, 1.5, 2 or 3 gr per kg of body weight, or with saline solution (control), respectively. Grossly, all intoxicated animals showed hemorrhages in abdominal serosas, epicardium, endocardium, spleen, pre-stomachs, abomasum, and small and large intestine, and diffuse edema of the ruminal mucosa. Microscopically, in all animals inoculated with R. communis seeds, the main feature was the presence of pyknotic and karyorrhectic nuclei in the endothelium of central nervous system, hepatic, ruminal, intestinal, glomerular and alveolar capillaries, and in lymphoid cells of multiple organs. Apoptosis, confirmed by activated caspase-3 immunohistochemistry, was observed in these cells. No gross or microscopic lesions were observed in the control animal. The results of this study suggest that apoptosis is the main mechanism of cell death in cattle intoxicated with R. communis seeds.(AU)

Pathology of cattle experimentally intoxicated with ground Ricinus communis seeds

Five Aberdeen Angus calves were inoculated intra-ruminally with ground seeds of Ricinus communis at doses of 1, 1.5, 2 or 3 gr per kg of body weight, or with saline solution (control), respectively. Grossly, all intoxicated animals showed hemorrhages in abdominal serosas, epicardium, endocardium, spleen, pre-stomachs, abomasum, and small and large intestine, and diffuse edema of the ruminal mucosa. Microscopically, in all animals inoculated with R. communis seeds, the main feature was the presence of pyknotic and karyorrhectic nuclei in the endothelium of central nervous system, hepatic, ruminal, intestinal, glomerular and alveolar capillaries, and in lymphoid cells of multiple organs. Apoptosis, confirmed by activated caspase-3 immunohistochemistry, was observed in these cells. No gross or microscopic lesions were observed in the control animal. The results of this study suggest that apoptosis is the main mechanism of cell death in cattle intoxicated with R. communis seeds.

White muscle disease in three selenium deficient beef and dairy calves in Argentina and Uruguay / Doença do músculo branco em três bezerros para carne e leite deficientes em selênio na Argentina e Uruguai

White muscle disease (WMD), nutritional myodegeneration or enzootic muscular dystrophy, is a nutritional condition associated with selenium and/or vitamin E deficiency in ruminants. These elements are constituents of the major body antioxidant systems. Depletion of selenium results in oxidative damage to cardiac and skeletal muscle cells, resulting in myodegeneration and myonecrosis, typical lesions of WMD. Selenium deficiency is common in South America, but WMD is underreported. This research describes clinical, biochemical and pathological findings in two episodes of WMD associated with selenium deficiency in beef and dairy calves in Argentina and Uruguay with concurrent copper deficiency in one of them, which resulted in spontaneous calf mortality. Further studies are necessary to estimate the true incidence and economic impact of clinical and subclinical mineral deficiencies in livestock production systems in the southern cone of South America.(AU)

Doença do músculo branco (DMB), miodegeneração nutricional ou distrofia muscular enzoótica é uma condição nutricional associada à deficiência de selênio e/ou vitamina E em ruminantes. Esses elementos são constituintes dos principais sistemas antioxidantes do corpo. O esgotamento de selênio resulta em dano oxidativo às células musculares cardíacas e esqueléticas, resultando em miodegeneração e mionecrose, lesões típicas da DMB. A deficiência de selênio é comum na América do Sul, mas a DMB está subnotificada. Este trabalho descreve os achados clínicos, bioquímicos e patológicos em dois surtos de DMB associados à deficiência de selênio em bezerros para carne e leite na Argentina e Uruguai com concomitante deficiência de cobre em um surto, que resultaram em mortalidade espontânea de bezerros. São necessários mais estudos para estimar a verdadeira incidência e impacto econômico das deficiências minerais clínicas e subclínicas nos sistemas de produção pecuária no sul da América do Sul.(AU)