title: Evidence of dehydration and electrolyte disturbances in cases of perennial ryegrass toxicosis in Australian sheep.
abstract: METHODS
  Perennial ryegrass toxicosis (PRGT) is a common disease entity in Australia, presenting as an association of clinical signs including alterations in normal behavioural, ataxia ('staggers'), ill thrift and gastrointestinal dysfunction ('scours'). Clinical signs can range in severity from mild (gait abnormalities and failure to thrive) to severe (seizures, lateral recumbency and death). Presentation across the flock is usually highly variable. PRGT is caused by toxins produced by the endophytic fungus Neotyphodium lolii, a symbiont of perennial ryegrass that is present in pastures across the temperate regions of Australia and Tasmania. A particular feature of PRGT in Australia is the occasional occurrence of large-scale sheep losses, suggesting other factors are influencing mortality rates compared with other PRGT risk zones such as North America and New Zealand. During 2011, producers in the state of Victoria experienced a mild outbreak of PRGT that affected large numbers of animals but with limited mortalities. Clinical samples taken from affected sheep showed a high incidence of dehydration and electrolyte abnormalities.
  
  
  CONCLUSIONS
  We speculate that changes in hydration status may be a contributory aetiological factor in those years in which high numbers of deaths are associated with PRGT outbreaks in Australia.
authors.affiliation: Plant and Animal Toxicology Group, School of Animal and Veterinary Science, Graham Centre for Agricultural Innovation, Charles Sturt University, Wagga Wagga, New South Wales, Australia.
authors.forename: M D A
authors.initials: MD
authors.lastname: Combs
authors.forename: D
authors.initials: D
authors.lastname: Rendell
authors.forename: K F M
authors.initials: KF
authors.lastname: Reed
authors.forename: W J
authors.initials: WJ
authors.lastname: Mace
authors.forename: J C
authors.initials: JC
authors.lastname: Quinn
mesh_terms: D000818:Animals; D002712:Chlorides / Q000097:blood; D003401:Creatine / Q000097:blood; D003681:Dehydration / Q000097:blood / Q000378:metabolism / Q000662:veterinary*; D004196:Disease Outbreaks / Q000662:veterinary*; D017809:Fatal Outcome; D005260:Female; D006400:Hematocrit / Q000662:veterinary; D006651:Histocytochemistry / Q000662:veterinary; D008129:Lolium / Q000378:metabolism* / Q000382:microbiology / Q000633:toxicity; D008297:Male; D055328:Neotyphodium / Q000378:metabolism*; D011188:Potassium / Q000097:blood; D012709:Serum Albumin / Q000032:analysis; D012756:Sheep; D012757:Sheep Diseases / Q000097:blood / Q000378:metabolism*; D012964:Sodium / Q000097:blood; D014508:Urea / Q000097:blood; D014739:Victoria
chemical_list: D002712:Chlorides; D012709:Serum Albumin; D014508:Urea; D012964:Sodium; D003401:Creatine; D011188:Potassium
keywords: dehydration; ergovaline; lolitrem B; perennial ryegrass; sheep; staggers; toxicosis