Polio causes

Wilson TM, Scholz RW, Drake TR.Selenium toxicity and porcine focal symmetrical poliomyelomalacia: description of a field outbreak and experimental reproduction. Can J Comp Med. 1983 Oct;47(4):412-21.PMID: 6667430 [PubMed - indexed for MEDLINE]
An acute afebrile paretic condition was diagnosed in 18 of 225 feeder pigs between eight to ten weeks of age. Nine pigs died acutely, seven pigs were euthanatized and two appeared to recover. Macroscopic lesions in the ventral horns of the cervical and lumbar/sacral spinal cord enlargements consisted of focal, bilateral, depressed areas. Histopathologically, the lesion consisted of endothelial proliferation, glial cell reaction and microcavitation. Similar lesions were observed in some brain stem motor nuclei. High selenium levels were detected in the pig feed and in pig tissues and blood. Two of five experimental pigs fed a commercial grower ration and supplemented with 52 ppm selenium as sodium selenite developed paresis and paralysis after a 29 day feeding trial. Histopathological lesions of focal symmetrical poliomyelomalacia confined to the cervical and lumbar/sacral spinal cord enlargements, and identical to those in the field cases, were produced. Select brain stem motor nuclei were also affected.

O'Toole D, Mills K, Ellis J, Welch V, Fillerup M.Poliomyelomalacia and ganglioneuritis in a horse with paralytic rabies.J Vet Diagn Invest. 1993 Jan;5(1):94-7. No abstract available.PMID: 8466989 [PubMed - indexed for MEDLINE]

Reznik M. Acute ascending poliomyelomalacia after treatment of acute lymphocytic leukemia.Acta Neuropathol (Berl). 1979 Feb 15;45(2):153-7.PMID: 283679 [PubMed - indexed for MEDLINE]

This paper reports the case of a 16-year-old girl with acute lymphoblastic leukemia who received chemotherapy including intrathecal injections of methotrexate and preventive irradiation of the brain, but not of the spinal cord. Several months later, she died from an acute ascending poliomyelitic syndrome evolving during 10 days. Clinical, bacteriological, and viral investigations failed to demonstrate any pathological agent. Autopsy revealed an acute ischemic lesion involving both anterior horns of the whole spinal cord and extending from the lower segment up to the mesencephalic region, without significant alteration of the white matter. Neither tumoral invasion, nor vascular obstruction was found. The pathogenesis of this yet undescribed lesion remained unclear but a metabolic disorder seemed the most plausible pathological factor.