RESUMO

Background: Fumonisins produced by Fusarium verticillioides are among the most important medical mycotoxins known. The intake of concentrate based on corn and corn by-products contaminated with fumonisins can cause severe poisoning in horses. The injuries are observed mainly in the white matter of the brain, and the disease is known as Equine Leukoencephalomalacia (ELEM). This study aims to describe and discuss the epidemiological, clinical and diagnostic aspects of an outbreak of ELEM occurred in three farms in the municipalities of Canarana and Água Boa, in the eastern region of Mato Grosso, Brazil. Materials, Methods & Results: The outbreak occurred between May and August 2010. The disease affected six horses and four mules of different ages and sex. Clinical examination was only possible in animals with chronic evolution of the disease. All the affected animals showed neurological clinical signs such as ataxia and recumbency, which progressed to death or sudden death. Histopathological analysis showed foci of necrosis that predominantly affected the white matter, and the presence of gitter cells. Degenerative lesions were observed in the liver of the animals. Mortality rate ranged from 12.5 to 71%, and lethality reached 100%. The cases were preceded by sudden drops in the weather temperature. Fumonisins levels of 6.6 ppm were detected in the feed of the animals. Discussion: The presumptive diagnosis of leukoencephalomalacia was consistent and based on clinical and epidemiological studies. However, the definitive diagnosis was based upon the histological features of the brain including the presence of extensive areas of malacia. Moreover, the animals were being fed with corn or corn by-products contaminated with fumonisins levels considered to be toxic to equids. The mortality and lethality rates are in agreement with outbreaks described in previous studies. The animals showed neurological signs as the predominant clinical manifestation, with gait ataxia followed by recumbency, prostration and death between 24 h and 29 days. Similarly to other reports, the disease was more frequent in adult animals, which succumbed in 24-48 h. Conversely, the evolution of the disease in young animals was of 10 to 29 days. Sudden death was more prevalent in the mules. Previous studies have shown a predominance of cerebral and brainstem lesions in horses, whereas in mules the clinical signs are related to brainstem lesions. Corn and corn byproducts are commonly used as energy supplementation to horses in the southern of Mato Grosso state, but outbreaks of the disease are uncommon. This may be influenced by the prevalence of hot climate conditions, which does not favor the production of toxin by the fungus. The atypical low weather temperatures (9-11ºC) observed prior to the outbreak could have contributed to the mycotoxin production by F. verticillioides, which requires temperatures between 8-12°C to produce toxins. However, the disease in the region may be underestimated, considering that the practice of necropsies is not common among field technicians, mainly in the occurrence of sporadic deaths among horses intended for work. Preventive measures include avoiding the use of corn and corn by-products for horses after periods of sudden drops in temperature in the region. Furthermore, clinical and epidemiological surveys and post-mortem and histopathological analyses are undoubtedly important for appropriate differential diagnosis, especially in equids with neurological signs.

Assuntos

RESUMO

Background: Fumonisins produced by Fusarium verticillioides are among the most important medical mycotoxins known. The intake of concentrate based on corn and corn by-products contaminated with fumonisins can cause severe poisoning in horses. The injuries are observed mainly in the white matter of the brain, and the disease is known as Equine Leukoencephalomalacia (ELEM). This study aims to describe and discuss the epidemiological, clinical and diagnostic aspects of an outbreak of ELEM occurred in three farms in the municipalities of Canarana and Água Boa, in the eastern region of Mato Grosso, Brazil. Materials, Methods & Results: The outbreak occurred between May and August 2010. The disease affected six horses and four mules of different ages and sex. Clinical examination was only possible in animals with chronic evolution of the disease. All the affected animals showed neurological clinical signs such as ataxia and recumbency, which progressed to death or sudden death. Histopathological analysis showed foci of necrosis that predominantly affected the white matter, and the presence of gitter cells. Degenerative lesions were observed in the liver of the animals. Mortality rate ranged from 12.5 to 71%, and lethality reached 100%. The cases were preceded by sudden drops in the weather temperature. Fumonisins levels of 6.6 ppm were detected in the feed of the animals. Discuss

Micotoxinas são substâncias produzidas por fungos que desenvolvem em sementes de cereais, com efeitos tóxicos passíveis de causar doenças ou mesmo morte nos animais após consumo. A presença das micotoxinas em alimentos está sujeita a influência de diversos fatores ambientais, variando em razão de determinadas condições, como produção e armazenamento. Dentre as micotoxinas de importância médica, destacam-se as fumonisinas, que são micotoxinas hidrossolúveis produzidas por Fusarium verticillioides, estáveis ao calor e resistentes ao tratamento com álcalis. [...]

RESUMO

Background: Fumonisins produced by Fusarium verticillioides are among the most important medical mycotoxins known. The intake of concentrate based on corn and corn by-products contaminated with fumonisins can cause severe poisoning in horses. The injuries are observed mainly in the white matter of the brain, and the disease is known as Equine Leukoencephalomalacia (ELEM). This study aims to describe and discuss the epidemiological, clinical and diagnostic aspects of an outbreak of ELEM occurred in three farms in the municipalities of Canarana and Água Boa, in the eastern region of Mato Grosso, Brazil. Materials, Methods & Results: The outbreak occurred between May and August 2010. The disease affected six horses and four mules of different ages and sex. Clinical examination was only possible in animals with chronic evolution of the disease. All the affected animals showed neurological clinical signs such as ataxia and recumbency, which progressed to death or sudden death. Histopathological analysis showed foci of necrosis that predominantly affected the white matter, and the presence of gitter cells. Degenerative lesions were observed in the liver of the animals. Mortality rate ranged from 12.5 to 71%, and lethality reached 100%. The cases were preceded by sudden drops in the weather temperature. Fumonisins levels of 6.6 ppm were detected in the feed of the animals. Discuss

Micotoxinas são substâncias produzidas por fungos que desenvolvem em sementes de cereais, com efeitos tóxicos passíveis de causar doenças ou mesmo morte nos animais após consumo. A presença das micotoxinas em alimentos está sujeita a influência de diversos fatores ambientais, variando em razão de determinadas condições, como produção e armazenamento. Dentre as micotoxinas de importância médica, destacam-se as fumonisinas, que são micotoxinas hidrossolúveis produzidas por Fusarium verticillioides, estáveis ao calor e resistentes ao tratamento com álcalis. [...]

RESUMO

In August 2007 an outbreak of neurological disease and sudden death in Arabian horses occurred in a farm located in Coronel Rosales County, Buenos Aires Province, Argentina. The animals were on a pasture of native grasses and supplemented ad libitum with corn kernels and wheat bran. Three horses were observed having acute neurologic signs including blindness, four leg ataxia, hyperexcitability, aimless walking and circling, followed by death in two of them. Four other horses were found dead overnight without a history of neurologic signs. The morbidity, mortality and lethality rates were 11.6 percent, 10 percent and 85.7 percent, respectively. Grossly, the brain showed focal areas of hemorrhage, brown-yellow discoloration and softening of the sub-cortical white matter. The microscopic brain lesions consisted of extensive areas of malacia within the white matter of the cerebral hemispheres, brainstem and cerebellum, characterized by rarefaction of the white matter with cavitations filled with proteinaceous edema, multifocal hemorrhages and mild infiltration by neutrophils, and rare eosinophils. Swollen glial cells with abundant eosinophilic cytoplasm, distinct cell borders, intracytoplasmic deeply eosinophilic globules and eccentric, hyperchromatic, occasionally pyknotic nucleus were present throughout the areas of rarefaction hemorrhage, edema and necrosis. The feed supplements contained 12,490µg/kg of fumonisin B1 and 5,251µg/ kg of fumonisin B2. This is the first reported outbreak of ELEM associated with consumption of feed supplements containing high concentrations of fumonisins in Argentina.(AU)

Em agosto de 2007, ocorreu um surto de doença neurológica e morte súbita em cavalos árabes em uma propriedade localizada no município de Coronel Rosales, na província de Buenos Aires, Argentina. Os animais estavam em pasto nativo e eram suplementados ad libitum com grãos de milho e farelo de trigo. Três cavalos foram observados com sinais neurológicos agudos, incluindo cegueira, ataxia nas quatro pernas, hiperexcitabilidade, e andar sem rumo e em círculo, seguidos de morte em dois animais. Outros quatro cavalos foram encontrados mortos durante a noite sem histórico de distúrbios neurológicos. A mortalidade, morbidade e letalidade foram de 11,6 por cento, 10 por cento e 85,7 por cento, respectivamente. Macroscopicamente, o cérebro tinha áreas focais de hemorragia, coloração amarelada e amolecimento da substância branca sub-cortical. Microscopicamente, as lesões cerebrais consistiram de extensas áreas de malácia na substância branca dos hemisférios cerebrais, do tronco encefálico e do cerebelo. Estas lesões da substância branca se caracterizaram por rarefação, cavidades contendo fluido proteináceo (edema), hemorragias multifocais e moderado infiltrado por neutrófilos e raros eosinófilos. Células gliais tumefeitas com abundante citoplasma eosinifílico, limites celulares evidentes, globules citoplasmáticos eosinofílicos, e núcleo excéntrico, hipercromático e ocasionalmente picnótico foram observadas nas areas de rarefacção, edema, hemorragias e necrose. Os suplementos alimentares continham 12.490µg/kg de fumonisina B1 e 5.251µg/ kg de fumonisina B2. Este é o primeiro surto reportado na Argentina de leucoencefalomalácia equina associado ao consumo de suplementos alimentares contendo altas concentrações de fumonisinas.(AU)

Assuntos

RESUMO

In August 2007 an outbreak of neurological disease and sudden death in Arabian horses occurred in a farm located in Coronel Rosales County, Buenos Aires Province, Argentina. The animals were on a pasture of native grasses and supplemented ad libitum with corn kernels and wheat bran. Three horses were observed having acute neurologic signs including blindness, four leg ataxia, hyperexcitability, aimless walking and circling, followed by death in two of them. Four other horses were found dead overnight without a history of neurologic signs. The morbidity, mortality and lethality rates were 11.6 percent, 10 percent and 85.7 percent, respectively. Grossly, the brain showed focal areas of hemorrhage, brown-yellow discoloration and softening of the sub-cortical white matter. The microscopic brain lesions consisted of extensive areas of malacia within the white matter of the cerebral hemispheres, brainstem and cerebellum, characterized by rarefaction of the white matter with cavitations filled with proteinaceous edema, multifocal hemorrhages and mild infiltration by neutrophils, and rare eosinophils. Swollen glial cells with abundant eosinophilic cytoplasm, distinct cell borders, intracytoplasmic deeply eosinophilic globules and eccentric, hyperchromatic, occasionally pyknotic nucleus were present throughout the areas of rarefaction hemorrhage, edema and necrosis. The feed supplements contained 12,490µg/kg of fumonisin B1 and 5,251µg/ kg of fumonisin B2. This is the first reported outbreak of ELEM associated with consumption of feed supplements containing high concentrations of fumonisins in Argentina.

Em agosto de 2007, ocorreu um surto de doença neurológica e morte súbita em cavalos árabes em uma propriedade localizada no município de Coronel Rosales, na província de Buenos Aires, Argentina. Os animais estavam em pasto nativo e eram suplementados ad libitum com grãos de milho e farelo de trigo. Três cavalos foram observados com sinais neurológicos agudos, incluindo cegueira, ataxia nas quatro pernas, hiperexcitabilidade, e andar sem rumo e em círculo, seguidos de morte em dois animais. Outros quatro cavalos foram encontrados mortos durante a noite sem histórico de distúrbios neurológicos. A mortalidade, morbidade e letalidade foram de 11,6 por cento, 10 por cento e 85,7 por cento, respectivamente. Macroscopicamente, o cérebro tinha áreas focais de hemorragia, coloração amarelada e amolecimento da substância branca sub-cortical. Microscopicamente, as lesões cerebrais consistiram de extensas áreas de malácia na substância branca dos hemisférios cerebrais, do tronco encefálico e do cerebelo. Estas lesões da substância branca se caracterizaram por rarefação, cavidades contendo fluido proteináceo (edema), hemorragias multifocais e moderado infiltrado por neutrófilos e raros eosinófilos. Células gliais tumefeitas com abundante citoplasma eosinifílico, limites celulares evidentes, globules citoplasmáticos eosinofílicos, e núcleo excéntrico, hipercromático e ocasionalmente picnótico foram observadas nas areas de rarefacção, edema, hemorragias e necrose. Os suplementos alimentares continham 12.490µg/kg de fumonisina B1 e 5.251µg/ kg de fumonisina B2. Este é o primeiro surto reportado na Argentina de leucoencefalomalácia equina associado ao consumo de suplementos alimentares contendo altas concentrações de fumonisinas.

Assuntos