PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

Thermal burn injuries are very uncommon occurrences in small ruminants worldwide, and in Brazil, there are no descriptions of this condition. Herein we describe an outbreak of dorsal thermal necrosis in a flock of sheep in the municipality of Boca da Mata, in the Forest Zone of the State of Alagoas, Northeastern Brazil. Twelve ewes were separated from the flock for a general clinical examination and evaluation the serum levels of urea, creatinine, gamma-glutamyltransferase, and aspartate aminotransferase. In addition, biopsies of the skin and liver were performed on two severely affected sheep. The flock was raised in semi-intensively management in a pasture area without shading and receiving approximately eight hours of insolation daily and developed severe dermatitis that evolved to severe necrosis of the dorsal skin. Grossly, these lesions were only observed in the dorsal skin of black sheep, while sheep with white dorsal areas of skin were not affected. Microscopically, the epidermis and deep dermis of affected sheep showed diffuse coagulative necrosis, pigmentary incontinence, and parakeratotic hyperkeratosis. Dorsal thermal necrosis occurs only in the dorsal skin of black sheep in situations of excessive exposure to sunlight due to the accumulation of ultraviolet radiation. The distribution of the lesions, restricted to the dorsal area of the skin, is an important clinicopathological aspect in these cases that can help differentiate lesions caused by photosensitization, as they usually involve other anatomical sites. To the authors’ knowledge, this is the first report of dorsal thermal necrosis in sheep in Brazil.

• Thermal necrosis sheep solar radiation small ruminants skin dry gangrene Brazilian northeastern.

Abstract in Portuguese:

o (UFRPE), Rua Dom Manuel Medeiros s/n, Dois Irmãos, Recife, PE 52171-900, Brazil. *Corresponding author: fabio.mendonca@ufrpe.br ABSTRACT.- Lima T.S., Fonseca S.M.C., Silva Filho G.B., Silva J.P.G., Tenório M.S.M., Melo E.T., Lucena R.B. & Mendonça F.S. 2023. Dorsal thermal necrosis in a Brazilian sheep flock. Pesquisa Veterinária Brasileira 43:e<Elocation>, 2023. Laboratório de Diagnóstico Animal, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros s/n, Dois Irmãos, Recife, PE 52171-900, Brazil. E-mail: fabio.mendonca@ufrpe.br Thermal burn injuries are very uncommon occurrences in small ruminants worldwide, and in Brazil, there are no descriptions of this condition. Herein we describe an outbreak of dorsal thermal necrosis in a flock of sheep in the municipality of Boca da Mata, in the Forest Zone of the State of Alagoas, Northeastern Brazil. Twelve ewes were separated from the flock for a general clinical examination and evaluation the serum levels of urea, creatinine, gamma-glutamyltransferase, and aspartate aminotransferase. In addition, biopsies of the skin and liver were performed on two severely affected sheep. The flock was raised in semi-intensively management in a pasture area without shading and receiving approximately eight hours of insolation daily and developed severe dermatitis that evolved to severe necrosis of the dorsal skin. Grossly, these lesions were only observed in the dorsal skin of black sheep, while sheep with white dorsal areas of skin were not affected. Microscopically, the epidermis and deep dermis of affected sheep showed diffuse coagulative necrosis, pigmentary incontinence, and parakeratotic hyperkeratosis. Dorsal thermal necrosis occurs only in the dorsal skin of black sheep in situations of excessive exposure to sunlight due to the accumulation of ultraviolet radiation. The distribution of the lesions, restricted to the dorsal area of the skin, is an important clinicopathological aspect in these cases that can help differentiate lesions caused by photosensitization, as they usually involve other anatomical sites. To the authors’ knowledge, this is the first report of dorsal thermal necrosis in sheep in Brazil. INDEX TERMS: Thermal necrosis, sheep, solar radiation, small ruminants, skin, dry gangrene, Brazilian northeastern. RESUMO.- [Necrose térmica dorsal em rebanho ovino brasileiro.] Lesões por queimaduras térmicas são ocorrências muito incomuns em pequenos ruminantes no mundo e no Brasil não há registros da ocorrência desta condição. Descreve-se um surto de necrose térmica dorsal em um rebanho de ovinos no município de Boca da Mata, Zona da Mata do Estado de Alagoas, Nordeste do Brasil. Doze ovelhas foram separadas do rebanho para realização de exame clínico geral e avaliação dos níveis séricos de uréia, creatinina,gama-glutamiltransferase e aspartato aminotransferase. Adicionalmente, biópsias de pele e fígado foram realizadas em duas ovelhas severamente afetadas. O rebanho era criado sob manejo semi-intensivo em uma área de pastagem sem sombreamento e recebiam aproximadamente oito horas de insolação diárias. Essas ovelhas desenvolveram dermatite severa que evoluiu para necrose da pele dorsal. Macroscopicamente, as lesões foram observadas apenas na pele dorsal de ovelhas negras, enquanto ovelhas com áreas dorsais brancas da pele não foram afetadas. Microscopicamente, a epiderme e a derme profunda das ovelhas afetadas apresentavam necrose coagulativa difusa, além de incontinência pigmentar e hiperqueratose paraqueratótica. A necrose térmica dorsal ocorre apenas na pele dorsal de ovelhas negras em situações de exposição excessiva à luz solar devido ao acúmulo de radiação ultravioleta. A distribuição das lesões, restrita à região dorsal da pele, é um importante aspecto clínico-patológico nesses casos que pode auxiliar na diferenciação das lesões causadas por fotossensibilização, pois geralmente envolvem outros sítios anatômicos. Este é o primeiro relato de necrose térmica dorsal em ovinos no Brasil.

• Necrose térmica ovinos radiação solar pequenos ruminantes pele gangrena seca nordeste brasileiro