title: Clinical expression of lolitrem B (perennial ryegrass) intoxication in horses.
abstract: BACKGROUND
  Perennial ryegrass staggers is purported to be a common neurological mycotoxicosis of horses but the case description lacks detail and evidence.
  
  
  OBJECTIVE
  To describe the clinical syndrome of lolitrem B intoxication in horses, limiting tests to those that are applicable to clinical practice, and to assess the potential value of enzyme-linked immunosorbent assay (ELISA) tests for lolitrem B in horse body fluids.
  
  
  METHODS
  Seven horses in 2 separate groups were fed perennial ryegrass seed and hay containing 2 ppm lolitrem B. Paired data were collected prior to and after 2 weeks exposure to lolitrem B, including video-documented neurological examination and clinical examination.
  
  
  RESULTS
  All horses developed a variable degree of tremor and ataxia when exposed to lolitrem B. Tremor depended on the level of activity and included a subtle, rapid tremor of the eyeball. Ataxia was exaggerated by blindfolding and primarily involved a truncal sway and irregular, but predictable, limb placements. No change was detected in urine lolitrem B levels and, although plasma lolitrem B increased during the treatment period, levels did not correlate with the severity of clinical signs displayed. Limb swelling, heel lesions and serous nasal discharge were also observed in horses most severely intoxicated.
  
  
  CONCLUSIONS
  The clinical effects of lolitrem B intoxication in horses primarily involve action-related tremors and symmetrical vestibular ataxia. Ergovaline may have caused the limb swelling, heel lesions and serous nasal discharge. Plasma ELISA for lolitrem B may be of diagnostic use in the future.
  
  
  CONCLUSIONS
  This study provides a clearer appreciation of the clinical signs and variability of perennial ryegrass intoxication in horses.
authors.affiliation: Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand. laurakjohnstone@gmail.com;
authors.forename: L K
authors.initials: LK
authors.lastname: Johnstone
authors.forename: I G
authors.initials: IG
authors.lastname: Mayhew
authors.forename: L R
authors.initials: LR
authors.lastname: Fletcher
mesh_terms: D000821:Animal Feed / Q000032:analysis / Q000633:toxicity; D000818:Animals; D001259:Ataxia / Q000139:chemically induced / Q000662:veterinary; D004879:Ergotamines / Q000032:analysis / Q000633:toxicity; D005260:Female; D006734:Horse Diseases / Q000139:chemically induced* / Q000175:diagnosis / Q000473:pathology; D006736:Horses; D026121:Indole Alkaloids; D008129:Lolium / Q000633:toxicity*; D008297:Male; D009183:Mycotoxins / Q000032:analysis / Q000633:toxicity*; D010939:Plant Poisoning / Q000175:diagnosis / Q000473:pathology / Q000662:veterinary*; D010947:Plants, Toxic / Q000633:toxicity; D012639:Seeds / Q000633:toxicity; D014202:Tremor / Q000139:chemically induced / Q000662:veterinary
chemical_list: D004879:Ergotamines; D026121:Indole Alkaloids; D009183:Mycotoxins; C076760:ergovaline; C033673:lolitrem B