Equis ISSN 2398-2977

Toxicity: venomous animals and insects of Australia

Contributor(s): Rosalind Dalefield, Christopher C Pollitt, Dawn Ruben, Andrew W van Eps, Vetstream Ltd

Introduction

Pathogenesis

Etiology

  • Australian snake venoms contain a wide variety of toxic components, with varying potential for:
    • Neurotoxicity.
    • Hemolytic activity.
    • Pro-coagulant or anticoagulant activity.
    • Cytotoxicity and myotoxicity.
  • Ixodes tick toxin exerts a variety of effects including interference with neuromuscular function, cranial nerve dysfunction, cardiac rhythm disturbances and central respiratory depression. The mechanisms are not fully understood.
  • Hymenoptera venoms are a complex mixture of toxic chemicals that cause local pain and swelling. There may also be systemic effects, including CNS (excitement), gastrointestinal (diarrhea) and respiratory (dyspnea) dysfunction. Anaphylaxis may also occur.

Timecourse

  • Onset of clinical signs of snake envenomation by Brown or Tiger snakes is usually rapid, though progression to death may occur over a period of up to 48 h in horses.
  • The clinical signs of tick paralysis may take up to 14 days to develop after attachment, though progression may be rapid from first clinical signs to death.
  • Hymenoptera stings cause an immediate reaction.

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.
  • Landolt G A (2007) Management of equine poisoning and envenomation. Vet Clin North Am Equine Pract 23 (1), 31-47 PubMed.
  • Shea G M (1999) The distribution and identification of dangerously venomous Australian terrestrial snakes. Aust Vet J 77 (12), 791-798 PubMed.
  • Mirtschin P J, Masci P, Paton D C & Kuchel T (1998) Snake bites recorded by veterinary practices in Australia. Aust Vet J 76 (3), 195-198 PubMed.
  • Arbuckle J B & Theakston R D (1992) Facial swelling in a pony attributable to an adder bite. Vet Rec 131 (4), 75-76 PubMed.
  • Arbuckle J B (1991) Facial swelling in cattle and horses. Vet Rec 129 (19), 436 PubMed.
  • Fitzgerald W E (1975) Snakebite in the horse. Aust Vet J 51 (1), 37-39 PubMed.
  • Pascoe R R (1975) Brown snake bite in horses in south-eastern Queensland. J S Afr Vet Assoc 46 (1), 129-131 PubMed.

Other sources of information

  • Tennent-Brown B & van Eps A (2008) Emergency diseases seen in Australia and New Zealand. In: Manual of Equine Emergencies: Treatment and Procedures. Eds: Orsini & Divers. 3rd edn. Saunders.
  • Best P (1998) Snake Envenomation in Companion Animals. In: Clinical Toxicology: Proc 318, Postgraduate Foundation in Veterinary Science. University of Sydney. 
  • Fitzgerald M P (1998) Ixodes holocyclus Poisoning. In: Clinical Toxicology: Proc 318, Postgraduate Foundation in Veterinary Science. University of Sydney. 
  • Little P (1998) Spider Envenomation in Dogs and Cats. In: Clinical Toxicology: Proc 318, Postgraduate Foundation in Veterinary Science. University of Sydney. 
  • Fowler M E (1992) Veterinary Zootoxicology. CRC Press.


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