Cases of poisoning by pyrrolizidine alkaloids (PAs) in ruminants and horses were surveilled retrospectively by accessing the files of two veterinary diagnostic laboratories in southern and northeastern Brazil. The data obtained were compared with those withdrawn from the literature and pertaining to outbreaks of the toxicosis in Brazil where it is associated with the ingestion of PAs-containing plants from the genera Senecio, Crotalaria and Echium. Acute and chronic forms of the toxicosis were encountered. Acute disease was observed in association with the ingestion of Crotalaria retusa in sheep and goats. C. retusa and Senecio spp. were also responsible for chronic poisoning in cattle, horses and sheep. PAs poisoning is an important cause of death in livestock in Brazil. It is the major cause of death in cattle in the Central region of Rio Grande do Sul and one of the major causes of death in horses in the state of Paraíba. The epidemiology, clinical signs, pathology, and importance of acute and chronic toxicoses are described and discussed.
Pseudocowpox virus is a parapoxvirus frequently associated with papulovesicular and scabby lesions on the teats and udders of milking cows and is often transmitted to human beings. An unusual outbreak of skin disease in fattening calves in southern Brazil is described. Fourteen of 17 male cattle (82%), aged 6–48 months, feeding on grass pastures were affected. Animals developed papules, vesicles, and scabby proliferative lesions on the muzzle in a clinical course of approximately 10–15 days. The scabby lesions often presented with exudation and bleeding. Histological examination of mucocutaneous tissue in detached scabs revealed acanthosis with thickening of the corneal layer and premature keratinization (parakeratotic hyperkeratosis). The dermis had multifocal lymphoplasmacytic infiltrates. Electron microscopic examination of scab specimens revealed typical parapoxvirus particles: oval shaped (260 nm × 160 nm), enveloped, and covered with a helical layer. Polymerase chain reaction using a set of pan-parapoxvirus primers for the B2L gene amplified a 590-bp product out of DNA extracted from scabs. Nucleotide sequencing of the amplicons revealed a nucleotide homology of 97% with Pseudocowpox virus and lower homology with other parapoxviruses: Bovine papular stomatitis virus (84%) and Orf virus (94%). A phylogenetic tree based on the B2L sequence was constructed, showing that the virus clustered with Pseudocowpox virus isolates.
Os aspectos epidemiológicos e anatomopatológicos de casos de hemangiossarcoma em cães da Região Central do RS foram estudados. Dos casos avaliados (n=40), cães idosos e da raça Pastor Alemão foram nitidamente os mais afetados (72,2% e 20% dos casos, respectivamente), visto que na população total de cães necropsiados nesse mesmo período (n=7.063) essa faixa etária e raça tiveram comparativamente uma prevalência bem mais baixa (14,6% e 10,1% dos casos, respectivamente). Na necropsia (n=40), os tumores ocorreram quase sempre como nódulos (92,5%) e, menos frequentemente, como massas (37,5%), e afetaram principalmente: baço (62,5%), pulmão (60%), fígado (52,5%), peritônio (42,5%), rim (37,5%), encéfalo (30%), pleura (25%) e coração (22,5%). Hemoperitônio (42,5%) e, consequentemente, anemia (22,5%) foram vistos com certa frequência. Na histologia (n=25), os hemangiossarcomas eram principalmente bem diferenciados (84%), de baixo grau (64%) e com estroma escasso (84%), mas frequentemente (68%) havia áreas com células demonstrando algum grau de atipia. Necrose, hemorragia e trombose foram vistos em todos os casos, mas hematopoiese extramedular (28%) e proliferação angiomatosa benigna (12%) foram achados menos comuns. Na imuno- -histoquímica (n=24), utilizando anticorpo anti-fator de von Willebrand, todos os casos demonstraram marcação de intensidade variável com um padrão citoplasmático finamente granular. Em relação à classificação anatômica, 55% dos hemangiossarcomas foram considerados como multicêntricos, 30% como primários com metástase(s) e 15% como solitários. Esse artigo discute esses resultados e propõe, com base em combinações de órgãos afetados, um esquema de separação entre hemangiossarcomas primário com metástase(s) e multicêntrico, a fim de tentar homogeneizar a maneira com que patologistas veterinários referem-se a esse neoplasma.
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