Bovis ISSN 2398-2993

Bluebell (glycoside) poisoning

Synonym(s): Bluebell (Hyacinthoides non-scripta), Spanish bluebell (Hyacinthoides hispanica), Italian bluebell (Hyacinthoides italica)

Contributor(s): Nicola Bates, Alan Murphy

Introduction

  • Cause: ingestion of bluebells.
  • Signs: anorexia, depression, signs of abdominal pain, weakness and weak pulse.
  • Diagnosis: based on history of exposure and clinical signs.
  • Treatment: supportive.
  • Prognosis: poor in animals with significant clinical signs.

Pathogenesis

Etiology

  • Exposure generally occurs in the spring.
  • Exposure could occur through ingestion of contaminated hay, although such cases have not been reported at the time of publication.

Predisposing factors

General

  • Access to bluebells.
  • Lack of or inability to access other forage.

Pathophysiology

  • All parts of these plants contain scillarens, which are cardiac glycosides similar in structure to those of foxglove (Digitalis spp).
  • Glycosidase-inhibiting alkaloids have also been described in bluebells and may contribute to the toxic effects.
  • The cardiac glycosides found in plants are generally precursors: primary glycosides that undergo enzymatic hydrolysis when plant material is dried or damaged to give the active (or secondary) glycosides.
  • Cardiac glycosides also interfere with the cellular membrane sodium-potassium (Na+ -K+ ATPase enzyme system) pump resulting in depletion of intracellular potassium and an increase in serum potassium. This causes irregular heart activity, and eventual complete block of cardiac conduction.
  • They also have irritant effects on the gastrointestinal tract.
  • Cardiac glycosides can result in cardiac arrhythmias. Dysrhythmias Dysrhythmias including first- and second-degree heart block and ventricular tachycardia. Pulse may be rapid, weak and irregular.

Timecourse

  • Limited information in cattle.
  • Signs are expected to occur within a few hours with recovery within 1-3 days.

Epidemiology

  • Poisoning can occur wherever bluebells grow.
  • Cases in cattle are rarely reported.

Diagnosis

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Treatment

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Prevention

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Outcomes

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Further Reading

Publications

Refereed Papers

  • Recent references from PubMed and VetMedResource.
  • Payne J & Murphy A (2014) Plant poisoning in farm animals. In Pract 36 (9), 455-465 VetMedResource.
  • Cutler K (2007) A case of suspected bluebell (Hyacinthoides non-scripta) poisoning in cattle. UK Vet 12 (2), 44-47 VetMedResource.
  • Watson A A, Nash R J et al (1997) Glycosidase-inhibiting pyrrolidine alkaloids from Hyacinthoides non-scripta. Phytochemistry 46 (2), 255-259.
  • Thursby-Pelham R H (1967) Suspected Scilla non-scripta (bluebell) poisoning in cattle. Vet Rec 80 (24), 709-710 PubMed.

Other sources of information

  • Burrows G E & Tyrl R J (2013) Toxic Plants of North America. 2nd edn. Wiley Blackwell, USA.
  • Cooper M R & Johnson A W (1998) Poisonous Plants and Fungi in Britain. 2nd edn. The Stationery Office, UK.

Organisation(s)

  • ASPCA Animal Poison Control Center. Tel: +1 (888) 426 4435; Website: www.aspca.org.
  • Veterinary Poisons Information Service (VPIS). Tel: +44 (0)2073 055 055; Website: www.vpisglobal.com.


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