Neuroaxonal degeneration in sheep grazing Sorghum pastures.

Gregory A Bradley, H. C. Metcalf, C. Reggiardo, T. H. Noon, E. J. Bicknell, F. Lozano-Alarcon, Michael W Riggs, M. W. Riggs

Research output: Contribution to journalArticle

25 Citations (Scopus)

Abstract

During the fall of 1992, 250 (10%) of 2,500 Rambouilet cross feeder lambs grazing Sorghum bicolor developed neurologic signs including weakness, ataxia, head shaking, knuckling of the fetlocks, inability to rise, and opisthotonos. One hundred fifteen (46%) of the affected lambs died. Twenty of the surviving lambs exhibited residual neurologic signs of ataxia when stressed. At the same time, 275 (25%) of 1,100 ewes grazing a nearby sudex pasture (S. sudanese x S. bicolor) gave birth to lambs that were weak and unable to rise. Newborn lambs exhibited extensor rigidity and opisthotonos when assisted to a standing position. The dystocias that occurred were due to lambs with contracted limbs (arthrogryposis). All affected lambs died or were euthanized. Histologic examination of the brains of 3 feeder lambs and 9 newborn lambs revealed similar microscopic lesions. The predominant change was the presence of focal axonal enlargements (spheroids) in the proximal segments of axons, which were restricted to the nuclei of the medulla, cerebellum, and midbrain. In addition, the spinal cord contained spheroids in the ventral horn gray matter of the 6 newborns examined. Ultrastructurally, the spheroids were composed of aggregates of neurofilaments, mitochondria, vesicular bodies, and dense bodies bounded by a thin myelin sheath. There was mild gliosis in the more severely affected animals of both groups. There was minimal Wallerian degeneration in the white matter adjacent to affected nuclei in the brain and the ventromedial and dorsolateral funiculi of the spinal cord. This is the first detailed report of Sorghum toxicity in sheep.

Original languageEnglish (US)
Pages (from-to)229-236
Number of pages8
JournalJournal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc
Volume7
Issue number2
StatePublished - Apr 1995

Fingerprint

Sorghum
Sorghum (Poaceae)
Sheep
lambs
pastures
grazing
Ataxia
Neurologic Manifestations
sheep
Spinal Cord
Arthrogryposis
Muscle Rigidity
Wallerian Degeneration
Gliosis
Intermediate Filaments
Brain
Horns
Myelin Sheath
Mesencephalon
Anthoxanthum

ASJC Scopus subject areas

  • Microbiology
  • veterinary(all)

Cite this

Neuroaxonal degeneration in sheep grazing Sorghum pastures. / Bradley, Gregory A; Metcalf, H. C.; Reggiardo, C.; Noon, T. H.; Bicknell, E. J.; Lozano-Alarcon, F.; Riggs, Michael W; Riggs, M. W.

In: Journal of veterinary diagnostic investigation : official publication of the American Association of Veterinary Laboratory Diagnosticians, Inc, Vol. 7, No. 2, 04.1995, p. 229-236.

Research output: Contribution to journalArticle

@article{1cac45b7c55d46b7b13b2ff21ace8436,
title = "Neuroaxonal degeneration in sheep grazing Sorghum pastures.",
abstract = "During the fall of 1992, 250 (10{\%}) of 2,500 Rambouilet cross feeder lambs grazing Sorghum bicolor developed neurologic signs including weakness, ataxia, head shaking, knuckling of the fetlocks, inability to rise, and opisthotonos. One hundred fifteen (46{\%}) of the affected lambs died. Twenty of the surviving lambs exhibited residual neurologic signs of ataxia when stressed. At the same time, 275 (25{\%}) of 1,100 ewes grazing a nearby sudex pasture (S. sudanese x S. bicolor) gave birth to lambs that were weak and unable to rise. Newborn lambs exhibited extensor rigidity and opisthotonos when assisted to a standing position. The dystocias that occurred were due to lambs with contracted limbs (arthrogryposis). All affected lambs died or were euthanized. Histologic examination of the brains of 3 feeder lambs and 9 newborn lambs revealed similar microscopic lesions. The predominant change was the presence of focal axonal enlargements (spheroids) in the proximal segments of axons, which were restricted to the nuclei of the medulla, cerebellum, and midbrain. In addition, the spinal cord contained spheroids in the ventral horn gray matter of the 6 newborns examined. Ultrastructurally, the spheroids were composed of aggregates of neurofilaments, mitochondria, vesicular bodies, and dense bodies bounded by a thin myelin sheath. There was mild gliosis in the more severely affected animals of both groups. There was minimal Wallerian degeneration in the white matter adjacent to affected nuclei in the brain and the ventromedial and dorsolateral funiculi of the spinal cord. This is the first detailed report of Sorghum toxicity in sheep.",
author = "Bradley, {Gregory A} and Metcalf, {H. C.} and C. Reggiardo and Noon, {T. H.} and Bicknell, {E. J.} and F. Lozano-Alarcon and Riggs, {Michael W} and Riggs, {M. W.}",
year = "1995",
month = "4",
language = "English (US)",
volume = "7",
pages = "229--236",
journal = "Journal of Veterinary Diagnostic Investigation",
issn = "1040-6387",
publisher = "American Association of Veterinary Laboratory Diagnosticians",
number = "2",

}

TY - JOUR

T1 - Neuroaxonal degeneration in sheep grazing Sorghum pastures.

AU - Bradley, Gregory A

AU - Metcalf, H. C.

AU - Reggiardo, C.

AU - Noon, T. H.

AU - Bicknell, E. J.

AU - Lozano-Alarcon, F.

AU - Riggs, Michael W

AU - Riggs, M. W.

PY - 1995/4

Y1 - 1995/4

N2 - During the fall of 1992, 250 (10%) of 2,500 Rambouilet cross feeder lambs grazing Sorghum bicolor developed neurologic signs including weakness, ataxia, head shaking, knuckling of the fetlocks, inability to rise, and opisthotonos. One hundred fifteen (46%) of the affected lambs died. Twenty of the surviving lambs exhibited residual neurologic signs of ataxia when stressed. At the same time, 275 (25%) of 1,100 ewes grazing a nearby sudex pasture (S. sudanese x S. bicolor) gave birth to lambs that were weak and unable to rise. Newborn lambs exhibited extensor rigidity and opisthotonos when assisted to a standing position. The dystocias that occurred were due to lambs with contracted limbs (arthrogryposis). All affected lambs died or were euthanized. Histologic examination of the brains of 3 feeder lambs and 9 newborn lambs revealed similar microscopic lesions. The predominant change was the presence of focal axonal enlargements (spheroids) in the proximal segments of axons, which were restricted to the nuclei of the medulla, cerebellum, and midbrain. In addition, the spinal cord contained spheroids in the ventral horn gray matter of the 6 newborns examined. Ultrastructurally, the spheroids were composed of aggregates of neurofilaments, mitochondria, vesicular bodies, and dense bodies bounded by a thin myelin sheath. There was mild gliosis in the more severely affected animals of both groups. There was minimal Wallerian degeneration in the white matter adjacent to affected nuclei in the brain and the ventromedial and dorsolateral funiculi of the spinal cord. This is the first detailed report of Sorghum toxicity in sheep.

AB - During the fall of 1992, 250 (10%) of 2,500 Rambouilet cross feeder lambs grazing Sorghum bicolor developed neurologic signs including weakness, ataxia, head shaking, knuckling of the fetlocks, inability to rise, and opisthotonos. One hundred fifteen (46%) of the affected lambs died. Twenty of the surviving lambs exhibited residual neurologic signs of ataxia when stressed. At the same time, 275 (25%) of 1,100 ewes grazing a nearby sudex pasture (S. sudanese x S. bicolor) gave birth to lambs that were weak and unable to rise. Newborn lambs exhibited extensor rigidity and opisthotonos when assisted to a standing position. The dystocias that occurred were due to lambs with contracted limbs (arthrogryposis). All affected lambs died or were euthanized. Histologic examination of the brains of 3 feeder lambs and 9 newborn lambs revealed similar microscopic lesions. The predominant change was the presence of focal axonal enlargements (spheroids) in the proximal segments of axons, which were restricted to the nuclei of the medulla, cerebellum, and midbrain. In addition, the spinal cord contained spheroids in the ventral horn gray matter of the 6 newborns examined. Ultrastructurally, the spheroids were composed of aggregates of neurofilaments, mitochondria, vesicular bodies, and dense bodies bounded by a thin myelin sheath. There was mild gliosis in the more severely affected animals of both groups. There was minimal Wallerian degeneration in the white matter adjacent to affected nuclei in the brain and the ventromedial and dorsolateral funiculi of the spinal cord. This is the first detailed report of Sorghum toxicity in sheep.

UR - http://www.scopus.com/inward/record.url?scp=0029286284&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0029286284&partnerID=8YFLogxK

M3 - Article

VL - 7

SP - 229

EP - 236

JO - Journal of Veterinary Diagnostic Investigation

JF - Journal of Veterinary Diagnostic Investigation

SN - 1040-6387

IS - 2

ER -