Degenerative axonopathy associated with copper deficiency in pigs

Abstract

RESUMO.-[Axonopatia degenerativa associada com deficiência de cobre em suínos.] São relatados os achados epidemiológicos, clínicos e morfológicos (patológicos e ultraestruturais) de quatro surtos de deficiência de cobre em suínos afetados entre 21 e 90 dias de idade na região Nordeste do Brasil. Os sinais clínicos iniciaram com paraparesia e ataxia, que progrediu a paralisia flácida ou espástica dos membros pélvicos e torácicos, seguido de decúbito esternal e/ou lateral. Além disso, alguns animais apresentaram posição de cão sentado e tremores de intenção. O perí-odo de manifestação clínica variou de 5-20 dias. Não foram observadas lesões macroscópicas significativas; no entanto, microscopicamente, foi observada degeneração simétri-ca da substância branca com fragmentação das bainhas de mielina, contendo ocasionais macrófagos, principalmente na medula espinal. The epidemiological, clinic and morphological (pathological and ultrastructural) aspects of four outbreaks of copper deficiency affecting 21-to 90-day-old pigs in the Northeast region of Brazil are reported. Clinical signs began with paraparesis and ataxia and progressed to flaccid or spastic paralysis of the pelvic and thoracic limbs, followed by sternal and/or lateral recumbence. In addition, some animals showed dog-sitting position and intention tremors. The clinical manifestation period was 5-20 days. Significant gross lesions were not observed; however, microscopically, symmetrical degeneration of the white matter with ballooned myelin sheaths containing occasional macrophages was observed, mainly in the spinal cord. Two pigs presented with necrosis ad loss of Purkinje cells and ectopic Purkinje cells in the granular layer and cerebellar white matter. A ultrastructural analysis showed different degrees of damage of myelinated axons in the spinal segments, including an absence of the axoplasm structures with only axonal residues remaining. The myelin sheaths were degenerated and often collapsed into the space previously occupied by the axon. These results suggest that myelin degeneration is secondary to the axonal lesion. Finally, the concentration of copper in the liver was determined using atomic absorption spectrophotometry and was found to be low (ranging from 2.2 to 10.8 ppm). In conclusion, in the Brazilian semiarid region, Cu deficiency occurs in 21 to 90-day-old pigs that ingested different types of waste in their food.INDEX TERMS: Degenerative myelopathy, axonal degeneration, myelin degeneration, copper deficiency, mineral deficiency, swine.

Motor and somatosensory degenerative myelopathy responsive to pantothenic acid in piglets

“…Chromatolysis and necrosis of neurons in the brain, midbrain, and brainstem were not reported in the pigs. 27,34 MN disease in pigs, which presumably has a hereditary basis, has been described in six 5-week-old Yorkshire and in six 6-week-old Hampshire pigs. 18,23 Yorkshire pigs presented bilateral posterior ataxia and weakness that rapidly progressed to tetraplegia by 10 weeks of age.…”