Postmortem diagnosis of idiopathic hyperammonemia in a horse

Lyndi L. Gilliam, Todd C. Holbrook, Julie E Dechant, Bill J. Johnson

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

A 6-year-old Quarter Horse stallion was referred to Oklahoma State University Veterinary Medical Teaching Hospital for evaluation of abdominal pain that developed after breeding activity earlier in the day. The horse developed diarrhea and progressively worsening neurologic signs (circling, ataxia, head pressing) within 22 hours of presentation and was subsequently euthanized due to severe self-destructive behavior. Antemortem biochemical and hematologic abnormalities included hypocalcemia but no evidence of hepatic disease. Idiopathic hyperammonemia and encephalopathy were suspected; cerebrospinal fluid (CSF) and aqueous humor were collected 10 hours postmortem for ammonia analysis using a colorimetric assay. Results were compared with those of 6 horses that also had been euthanized, for diseases unrelated to encephalopathy. Ammonia also was measured in plasma samples obtained antemortem. Ammonia concentrations in plasma (958 μmol/L), CSF (1566 μmol/L) and aqueous humor (1018 μmol/L) samples from the stallion were markedly increased compared to those in the 6 unaffected horses (plasma, 9-43 μmol/L; CSF, 370-532 μmol/L; aqueous humor, 70-483 μmol/L). Since the acute nature of hyperammonemic encephalopathy often does not provide sufficient time for an antemortem diagnosis, postmortem analysis of CSF and aqueous humor ammonia concentrations may be a useful alternative for documenting hyperammonemia in horses.

Original languageEnglish (US)
Pages (from-to)196-199
Number of pages4
JournalVeterinary Clinical Pathology
Volume36
Issue number2
DOIs
StatePublished - Jun 2007

Fingerprint

Cerebrospinal fluid
Hyperammonemia
cerebrospinal fluid
Ammonia
Aqueous Humor
encephalopathy
Horses
ammonia
Cerebrospinal Fluid
horses
Brain Diseases
stallions
Plasmas
water
Quarter Horse
hypocalcemia
liver diseases
pressing
Self-Injurious Behavior
nervous system

Keywords

  • Encephalopathy
  • Equine
  • Horse
  • Hyperammonemia

ASJC Scopus subject areas

  • Biochemistry, Genetics and Molecular Biology(all)
  • veterinary(all)

Cite this

Postmortem diagnosis of idiopathic hyperammonemia in a horse. / Gilliam, Lyndi L.; Holbrook, Todd C.; Dechant, Julie E; Johnson, Bill J.

In: Veterinary Clinical Pathology, Vol. 36, No. 2, 06.2007, p. 196-199.

Research output: Contribution to journalArticle

Gilliam, Lyndi L. ; Holbrook, Todd C. ; Dechant, Julie E ; Johnson, Bill J. / Postmortem diagnosis of idiopathic hyperammonemia in a horse. In: Veterinary Clinical Pathology. 2007 ; Vol. 36, No. 2. pp. 196-199.
@article{6afe2442efc540649e67a0cbc4ba0a9f,
title = "Postmortem diagnosis of idiopathic hyperammonemia in a horse",
abstract = "A 6-year-old Quarter Horse stallion was referred to Oklahoma State University Veterinary Medical Teaching Hospital for evaluation of abdominal pain that developed after breeding activity earlier in the day. The horse developed diarrhea and progressively worsening neurologic signs (circling, ataxia, head pressing) within 22 hours of presentation and was subsequently euthanized due to severe self-destructive behavior. Antemortem biochemical and hematologic abnormalities included hypocalcemia but no evidence of hepatic disease. Idiopathic hyperammonemia and encephalopathy were suspected; cerebrospinal fluid (CSF) and aqueous humor were collected 10 hours postmortem for ammonia analysis using a colorimetric assay. Results were compared with those of 6 horses that also had been euthanized, for diseases unrelated to encephalopathy. Ammonia also was measured in plasma samples obtained antemortem. Ammonia concentrations in plasma (958 μmol/L), CSF (1566 μmol/L) and aqueous humor (1018 μmol/L) samples from the stallion were markedly increased compared to those in the 6 unaffected horses (plasma, 9-43 μmol/L; CSF, 370-532 μmol/L; aqueous humor, 70-483 μmol/L). Since the acute nature of hyperammonemic encephalopathy often does not provide sufficient time for an antemortem diagnosis, postmortem analysis of CSF and aqueous humor ammonia concentrations may be a useful alternative for documenting hyperammonemia in horses.",
keywords = "Encephalopathy, Equine, Horse, Hyperammonemia",
author = "Gilliam, {Lyndi L.} and Holbrook, {Todd C.} and Dechant, {Julie E} and Johnson, {Bill J.}",
year = "2007",
month = "6",
doi = "10.1111/j.1939-165X.2007.tb00209.x",
language = "English (US)",
volume = "36",
pages = "196--199",
journal = "Veterinary Clinical Pathology",
issn = "0275-6382",
publisher = "American Society for Veterinary Clinical Pathology",
number = "2",

}

TY - JOUR

T1 - Postmortem diagnosis of idiopathic hyperammonemia in a horse

AU - Gilliam, Lyndi L.

AU - Holbrook, Todd C.

AU - Dechant, Julie E

AU - Johnson, Bill J.

PY - 2007/6

Y1 - 2007/6

N2 - A 6-year-old Quarter Horse stallion was referred to Oklahoma State University Veterinary Medical Teaching Hospital for evaluation of abdominal pain that developed after breeding activity earlier in the day. The horse developed diarrhea and progressively worsening neurologic signs (circling, ataxia, head pressing) within 22 hours of presentation and was subsequently euthanized due to severe self-destructive behavior. Antemortem biochemical and hematologic abnormalities included hypocalcemia but no evidence of hepatic disease. Idiopathic hyperammonemia and encephalopathy were suspected; cerebrospinal fluid (CSF) and aqueous humor were collected 10 hours postmortem for ammonia analysis using a colorimetric assay. Results were compared with those of 6 horses that also had been euthanized, for diseases unrelated to encephalopathy. Ammonia also was measured in plasma samples obtained antemortem. Ammonia concentrations in plasma (958 μmol/L), CSF (1566 μmol/L) and aqueous humor (1018 μmol/L) samples from the stallion were markedly increased compared to those in the 6 unaffected horses (plasma, 9-43 μmol/L; CSF, 370-532 μmol/L; aqueous humor, 70-483 μmol/L). Since the acute nature of hyperammonemic encephalopathy often does not provide sufficient time for an antemortem diagnosis, postmortem analysis of CSF and aqueous humor ammonia concentrations may be a useful alternative for documenting hyperammonemia in horses.

AB - A 6-year-old Quarter Horse stallion was referred to Oklahoma State University Veterinary Medical Teaching Hospital for evaluation of abdominal pain that developed after breeding activity earlier in the day. The horse developed diarrhea and progressively worsening neurologic signs (circling, ataxia, head pressing) within 22 hours of presentation and was subsequently euthanized due to severe self-destructive behavior. Antemortem biochemical and hematologic abnormalities included hypocalcemia but no evidence of hepatic disease. Idiopathic hyperammonemia and encephalopathy were suspected; cerebrospinal fluid (CSF) and aqueous humor were collected 10 hours postmortem for ammonia analysis using a colorimetric assay. Results were compared with those of 6 horses that also had been euthanized, for diseases unrelated to encephalopathy. Ammonia also was measured in plasma samples obtained antemortem. Ammonia concentrations in plasma (958 μmol/L), CSF (1566 μmol/L) and aqueous humor (1018 μmol/L) samples from the stallion were markedly increased compared to those in the 6 unaffected horses (plasma, 9-43 μmol/L; CSF, 370-532 μmol/L; aqueous humor, 70-483 μmol/L). Since the acute nature of hyperammonemic encephalopathy often does not provide sufficient time for an antemortem diagnosis, postmortem analysis of CSF and aqueous humor ammonia concentrations may be a useful alternative for documenting hyperammonemia in horses.

KW - Encephalopathy

KW - Equine

KW - Horse

KW - Hyperammonemia

UR - http://www.scopus.com/inward/record.url?scp=34250354455&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=34250354455&partnerID=8YFLogxK

U2 - 10.1111/j.1939-165X.2007.tb00209.x

DO - 10.1111/j.1939-165X.2007.tb00209.x

M3 - Article

C2 - 17523096

AN - SCOPUS:34250354455

VL - 36

SP - 196

EP - 199

JO - Veterinary Clinical Pathology

JF - Veterinary Clinical Pathology

SN - 0275-6382

IS - 2

ER -