Acetogenin-induced fibrotic heart disease from avocado (Persea americana, Lauraceae) poisoning in horses.

Poisoning by avocado (Persea americana) has been confirmed in sheep, goats, dogs, rabbits and ostriches. The clinical signs and lesions are attributed to the acetogenin, persin. Little is known regarding the epidemiology, clinical signs, lesions and therapy caused by acetogenin-induced heart damage. During the two-year study, we investigated a horse farm with six horses that often fed themselves with P. americana leaves or mature fruit pulp and skin on the ground. Two horses died, and one underwent necropsy, histopathology, and immunohistochemistry using the anti-cardiac troponin C (cTnC). Grossly and histopathologically, there was severe cardiac fibroplasia. Immunohistochemically, there was a multifocal decrease or negative expression in the cTnC cardiomyocytes' cytoplasm. Persea americana leaves were confirmed in the alimentary tract using botanical anatomy and molecular techniques. The chemical investigation by (LC-ESI-MS) revealed the presence of the acetogenins, persin and avocadene 1-acetate from P. americana. Persin was present in leaves and fruits (seed and pulp), while avocadene 1-acetate was found in leaves and fruits (seed, peel, and pulp) with a higher concentration in the pulp. Four other horses have been examined by electrocardiogram, echocardiogram and serum Troponin 1 (cTnI). To establish a causal effect of consumption of P. Americana and heart fibroplasia in horses, long-time experiments must be carried out.

Cestrum axillare (Solanaceae) poisoning in ruminants.

Cestrum axillare poisoning causes significant economic losses in farms of ruminant production due to a fatal acute hepatic disease. The consumption of C. axillare occurs on farms or pastures with a scarcity of feed or with dry forage. Epidemiological, clinical, and pathological data of poisoning outbreaks by C. axillare from 1953 to 2021 in grazing ruminants in southeastern Brazil are reported. A total of 68 bovines, two buffaloes, and two goats exhibited clinical signs and resulted in death due to C. axillare consumption, with 79% of the cases occurring during the dry period. Clinical signs were apathy, anorexia, ruminal arrest, arched back, and constipation with hard stools, sometimes with blood or mucus. Cases with neurological signs due to hepatic encephalopathy showed excitement, aggressiveness, drooling, staggering, and muscle tremors. The pathological findings included hepatocellular necrosis in the liver and microcavitations in the brain's white matter (status spongiosus). The hepatotoxins, carboxyparquin and parquin, were detected in C. axillare leaf samples collected from paddocks grazed by cattle in three southeastern Brazilian municipalities where outbreaks of C. axillare poisoning occurred. This is the first report of parquin and carboxyparquin in C. axillare.

An outbreak of malignant catarrhal fever in Sambar deer (Rusa unicolor) / Surto de febre catarral maligna em cervos Sambar (Rusa Unicolor)

Malignant catarrhal fever (MCF) is an infectious, pansystemic and highly fatal disease with wide geographic distribution. The species that are clinically prone to it include cattle, deer and bison. In Brazil, the disease in ruminants and deer is associated with the contact with sheep, especially during labor, when the fetal remains that are eliminated contain the ovine herpesvirus 2 (OvHV-2). The outbreak took place in a conservationist property in the city of Casimiro de Abreu/RJ, which hosted 23 Sambar deer, and, of these, 19 died, showing neurological signs. The deer lived in a location together with 15 male and female meat sheep. A female specimen of the Sambar deer (Rusa unicolor), aged approximately three years, which had presented with neurological clinical signs was referred to necropsy in the Setor de Anatomia Patológica at Universidade Federal Rural do Rio de Janeiro (SAP/UFRRJ). During necropsy, cerebrospinal fluid was sampled for analysis; fragments of several organs were fixated in 10% buffered formalin and processed for histopathological analysis. Fragments of occipital lobe, cerebellum and bulb were collected to perform the polymerase chain reaction (PCR). The diagnosis of this outbreak was based on epidemiological, clinical and pathological findings, and on the amplification of the OvHV-2 DNA through PCR. The histological changes were the base to confirm the MCF case and were characterized by degeneration of vascular endothelial cells, fibrinoid vasculitis, hyperplasia and necrosis of lymphoid organs. However, PCR was an important tool to confirm the diagnosis. MCF as an important disease with nervous symptomatology in deer.(AU)

A febre catarral maligna (FCM) é uma doença infecciosa, com distribuição geográfica ampla, pansistêmica e altamente fatal. As espécies clinicamente suscetíveis incluem bovino, cervo e bisão. No Brasil, a doença em ruminantes e cervídeos está associada ao contato com ovinos, principalmente durante o parto, no qual os envoltórios fetais eliminados contém, em suas secreções, o Herpesvírus ovino-2 (OvHV-2). O surto ocorreu em uma propriedade conservacionista no município de Casimiro de Abreu/RJ, que abrigava 23 cervos exóticos, onde foram registradas a morte de 19 destes, com sinais neurológicos. Os cervos habitavam em um piquete com 15 ovinos de corte, machos e fêmeas. Um exemplar de cervo sambar (Rusa unicolor), fêmea, com aproximadamente três anos de idade, que havia apresentado sinais clínicos neurológicos foi encaminhado para necropsia no Setor de Anatomia Patológica da Universidade Federal Rural do Rio de Janeiro (SAP/UFRRJ). Durante a necropsia foi realizada a coleta de líquido cefalorraquidiano e de fragmentos de lobo occipital, cerebelo e bulbo, para a realização de reação em cadeia da polimerase (PCR). Fragmentos de diversos órgãos foram fixados em formalina 10% tamponada e processados para a análise histopatológica. O diagnóstico do presente surto foi estabelecido com base nos achados epidemiológicos, clínicos, patológicos e na amplificação do DNA do OvHV-2 através da PCR. As alterações histológicas foram a base para confirmar o caso de FCM e caracterizaram-se por degeneração de células endoteliais vasculares, vasculite fibrinoide, hiperplasia dos órgãos linfoides. Contudo, a PCR foi uma ferramenta importante para a confirmação do diagnóstico. Ressalta-se a importância da FCM na lista dos diagnósticos diferenciais de doenças que cursam com sintomatologia nervosa em cervídeos.(AU)