Outbreaks of Brachiaria ruziziensis and Brachiaria brizantha intoxications in Brazilian experienced cattle.

Brachiaria species are some of the most used forage species for raising Brazilian cattle because of their great nutritional value and adaptability to the tropical climate. However, cases of animal intoxication have been described. Animal species, age, genetic resistance, and previous adaptation to the forage can influence the susceptibility to intoxication. Cattle (young or adults), other adult ruminants and animals adapted to consumption (experienced flocks) are considered more resistant. The main clinical presentation is that of hepatogenous photosensitization. Brachiaria brizantha and Brachiaria ruziziensis are considered less toxic. The aim of this study is to describe three outbreaks of intoxication by B. brizantha and B. ruziziensis in experienced cattle, as well as to compare the concentrations of protodioscin in paddocks with and without clinical cases. It was observed that the two forage species are toxic to all age groups of cattle adapted to their consumption, and the concentrations of protodioscin present in the plant cannot be used as the only criterion for determining the occurrence of intoxication.

Ovine gammaherpesvirus 2 infections in cattle without typical manifestations of sheep-associated malignant catarrhal fever and concomitantly infected with bovine coronavirus.

Sheep-associated malignant catarrhal fever (SA-MCF) is a severe, frequently fatal, lymphoproliferative disease that affects a wide variety of ruminants and is caused by ovine gammaherpesvirus 2 (OvHV-2), a member of the MCF virus (MCFV) complex. The typical clinical manifestations of SA-MCF are well known and easily recognized by veterinarians, resulting in clinical diagnosis of MCF when characteristic clinical signs are present. This article describes the findings observed in cattle infected with OvHV-2 but without typical clinical manifestations of SA-MCF. Three calves with episodes of diarrhea before death and a yearling that died suddenly were investigated. Gross alterations were not suggestive of SA-MCF. Histopathology revealed a combination of proliferating vascular lesions (PVLs) and necrotizing vasculitis in three animals (two calves and the yearling); with PVLs being identified only at the carotid rete mirabile of two calves infected with OvHV-2. Additional significant histopathologic lesions included atrophic enteritis, portal lymphocytic hepatitis, interstitial pneumonia, suppurative bacterial bronchopneumonia, and pulmonary hemorrhage. An immunohistochemical assay designed to identify only antigens of MCFV revealed, positive, intralesional, intracytoplasmic immunoreactivity within epithelial cells of multiple tissues of all animals with PVLs. PCR assays amplified OvHV-2 DNA from multiple tissues of the animals that contained MCFV proteins, confirming the MCFV identified as OvHV-2. Additionally, bovine coronavirus (BCoV) nucleic acids were amplified from tissues of all animals, including the animal not infected by OvHV-2. Collectively, these findings confirmed the participation of OvHV-2 in the development of the disease patterns observed in these animals that were concomitantly infected by BCoV and provide additional confirmation that cattle can be subclinically infected with OvHV-2. Consequently, the real occurrence of OvHV-2-related disease may be more elevated than reported, since asymptomatic or subclinically infected animals are not likely to be investigated for OvHV-2. Furthermore, PVLs should be included as possible histologic indicators of OvHV-2-related diseases in ruminants.

Bee stings in Brazil: Epidemiological aspects in humans.

Bees are insects of the order Hymenoptera and are involved in human accidents. In Brazil, bees that cause accidents are crosses derived from Europeans with African bees and are known for their aggressive behavior. Despite being considered an important public health concern, epidemiological studies at the national level are scarce. The objective of this study was to verify the epidemiological profile of bee accidents in humans in Brazil, using data from 2009 to 2019 of the Brazilian Ministry of Health. It was found that bee accidents increased by 207.61% from the first to the last year of the present study. The incidence varied according to the geographical region; the southern region had more bee accidents, but the Northern region had more deaths caused by bee accidents. Besides, climatic conditions were associated with susceptibility to bee stings; the incidence was higher during spring and summer. Age was also associated with fatality rate, with the elderly being the group with the highest fatality rate. Our results demonstrate that accidents caused by bees involve factors related to patients, the environment, and the behavior of bees. It is important to know the epidemiological aspects to help prevent apidic accidents.

Bovine upper alimentary squamous cell carcinoma associated with bracken fern poisoning: Clinical-pathological aspects and etiopathogenesis of 100 cases.

Upper digestive tract (UDT) cancer is rare in cattle, however in Southern Brazil, the UDT squamous cell carcinomas (SCCs) are relatively common and have been associated with bracken fern consumption and the presence of papillomas. Although a theory of pathogenesis considers bovine papillomavirus type 4 (BPV-4) as a cofactor in the development of these SCCs, some aspects of the etiopathogenesis of this disease need to be more investigated. In fact, detection of BPV-4 in UDT papillomas is scarce in other regions of the world and has not been performed in Brazil. Therefore, this study had two aims: 1) to analyze the epidemiological, clinical and pathological aspects of 100 natural cases of SCCs in the UDT of cattle grazing on bracken fern (Pteridium arachnoideum) highly contaminated areas, investigating the associations between these parameters; and 2) to investigate the presence of papillomavirus DNA by polymerase chain reaction (PCR) in the UDT papillomas (n = 47) from 30 cattle that also had UDT SCCs. There were statistically significant associations between clinical signs and tumor localization in the UDT; between histological grade of differentiation and tumor localization; and a trend towards significant association between histological grade of differentiation and presence of metastases. The average age of cattle with oropharyngeal SCCs was 7.39 years, with statistically significant difference comparing to cattle with esophageal SCCs (8.6 years). No statistical association was observed among other clinical-pathological parameters (growth pattern and primary site of the tumor) analyzed. No BPV DNA was detected in papillomas by PCR. Therefore, these results suggest the possibility that papillomas of the UDT are not necessarily associated with BPV infection.

Chronic liver disease in cattle associated with ingestion of Brachiaria spp. / Doença hepática crônica em bovinos associada com ingestão de Brachiaria spp.

ABSTRACT: One hundred and ninety livers condemned due to chronic disease (fibrosis) were evaluated in a bovine slaughterhouse over 12 months. Hepatic lymph nodes were also examined while still attached to livers. The major macroscopic lesion observed in the livers was moderate to severe atrophy of the left lobe associated with compensatory hypertrophy of the right lobe. Histologically, the main changes corresponded to sites of macroscopic lesions, and fibrosis was observed in all livers, along with bile duct hyperplasia and neovascularization. Masson's trichrome stain highlighted the fibrous connective tissue. Most of the livers analyzed had macrophages with foamy cytoplasm and a peripheral nucleus that infiltrated fibrotic areas. Immunohistochemistry (IHC) for macrophages with monoclonal antibody clone MAC 387 revealed that the cytoplasm of the foamy macrophages of the liver and of the hepatic lymph nodes were positively immunostained. These cells are frequently associated to the consumption of grasses of the genus Brachiaria. Although the liver gross lesions described in this study have not been previously reported in animals consuming Brachiaria , the associated changes observed histologically, such as fibrosis and infiltration of foamy macrophages, showed a new form of chronic liver disease probably associated with the consumption of this forage. The IHC technique was important to prove that the foam cells observed are macrophages.

RESUMO: Cento e noventa e dois fígados condenados devido à doença crônica (fibrose) foram avaliados em um abatedouro de bovinos durante 12 meses. Os linfonodos hepáticos, quando ainda estavam ligados aos fígados, também foram examinados. A principal lesão macroscópica observada no fígado foi moderada a acentuada atrofia do lobo esquerdo associada à hipertrofia compensatória do lobo direito. Histologicamente, as principais alterações correspondiam aos locais das lesões macroscópicas, e fibrose foi observada em todos os fígados, juntamente com a hiperplasia de ductos biliares e neovascularização. A coloração de Tricrômico de Masson destacou o tecido conjuntivo fibroso. A maioria dos fígados analisados apresentavam macrófagos com citoplasma espumoso e um núcleo periférico que infiltravam as áreas de fibrose. A imuno-histoquímica (IHQ) para macrófagos realizada com o anticorpo monoclonl clone MAC 387 revelou imunomarcação positiva no citoplasma dos macrófagos espumosos do fígado e dos linfonodos hepáticos. Essas células estão frequentemente associadas ao consumo de gramíneas do gênero Brachiaria . Apesar das lesões hepáticas macroscópicas descritas neste trabalho não terem sido previamente relatadas em animais que consomem Brachiaria , as alterações histológicas associadas, como fibrose e infiltração de macrófagos espumosos, mostram uma nova forma crônica de doença hepática provavelmente associada à ingestão desta forragem. A técnica de IHQ foi importante para provar que as células espumosas observadas são macrófagos.