Polioencephalomalacia in buffaloes em confinamento

Polioencephalomalacia (PEM) is a nervous disease that affects ruminants, has a worldwide distribution and causes significant economic losses. PEM is abundantly described and studied in cattle and small ruminants, but there is little information about the disease in buffaloes, especially in Brazil. The objective of this work is to describe the clinical and pathological aspects of an outbreak of PEM in buffaloes in a feedlot in the state of Pará, Brazil. The outbreak occurred in a flock of 76 Murrah buffaloes, with an average age of five months, in a feedlot. Twenty-eight of these buffaloes became ill, and thirteen showed neurological signs and died. Two buffaloes underwent necropsy. The brain and fragments of various abdominal and thoracic cavity organs were fixed in 10% formalin and sent for histopathological examination. In the frontal, parietal, and occipital telencephalic lobes, the convolutions were flattened and yellowish, and when cut, there was a clear line of demarcation between the superficial and deep layers. Histologically, the intermediate layers of the cerebral cortex showed mild to moderate vacuolization of the neuropil, moderate enlargement of the perivascular, perineuronal, and periastrocyte spaces, moderate swelling and edema of astrocytes, and a large number of necrotic neurons. The work demonstrates that, despite being poorly documented in Brazil, PEM should be considered in the differential diagnosis of neurological syndromes in buffaloes. Key words: buffaloes, pathology, cerebrocortical necrosis, laminar necrosis, thiamine. Polioencefalomalacia (PEM) é uma doença nervosa complexa que afeta ruminantes, tem distribuição mundial e causa perdas económicas significativas. A PEM é abundantemente descrita e estudada em bovinos e pequenos ruminantes, porém há poucas informações sobre a doença em bubalinos, especialmente no Brasil. O objetivo deste trabalho é descrever os aspectos clínicos e patológicos de um surto de PEM em búfalos em um confinamento no estado do Pará, Brasil. O surto ocorreu em um lote de 76 búfalos da raça Murrah, com idade média de cinco meses, em um sistema de confinamento. Vinte e oito desses bubalinos adoeceram e treze apresentaram sinais neurológicos e morreram. Dois bubalinos foram submetidos à necropsia. O encéfalo e fragmentos de diversos órgãos da cavidade abdominal e torácica foram fixados em formol a 10% e enviados para exame histopatológico. Nos lobos frontal, parietal e occipital do telencéfalo as circunvoluções