Canis ISSN: 2398-2942

Mycotoxicoses

Synonym(s): Aflatoxin poisoning, Aflatoxicosis, Vomitoxin poisoning, Penitrem A poisoning, Roquefortine poisoning, Tremorgenic Mycotoxicosis

Contributor(s): Rosalind Dalefield, Patricia Talcott

Introduction

  • These are diseases caused by ingestion of fungal toxins in food or food scraps. See also Mushroom and toadstool poisonings Mushroom poisoning.

Pathogenesis

Pathophysiology

  • Aflatoxins are converted to their epoxides by a cytochrome P450 in the liver. The highly reactive epoxides bind to and damage DNA, proteins and other macromolecules throughout cells. Hepatocellular degeneration and necrosis ultimately leads to impaired liver function, including synthesis of clotting factors.
  • Vomitoxin and the stachybotryotoxins are trichothecenes. These compounds are potent inhibitors of protein synthesis and nucleic acid synthesis, and are immunosuppressants. They are directly cytotoxic causing irritation and necrosis of the mouth and gastrointestinal tract in the case of ingested vomitoxin, and skin in the case of dog bedding contaminated with stachybotryotoxins.
  • The tremorgenic mycotoxins are derivatives of lysergic acid. They have been shown to reduce concentrations and/or function of the inhibitory amino acids GABA and glycine in the CNS. They have also been shown to cause vasoconstriction of cerebral vessels, which may lead to cerebral anoxia.

Timecourse

  • Aflatoxicosis in the dog is usually acute to subacute (a few days) in contrast to the chronic aflatoxicosis reported in livestock.
  • The trichothecenes also act within one to a few days.
  • Clinical signs of tremorgenic mycotoxicosis may develop within 30 min of ingestion.

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.
  • Munday J S, Thompson D, Finch S C, Babu J V, Wilkins A L, di Menna M E, Miles C O (2008) Presumptive tremorgenic mycotoxicosis in a dog in New Zealand, after eating mouldy walnuts. NZ Vet J 56 (3), 145-148 PubMed.
  • Young K L, Villar D, Carson T L, Ierman P M, Moore R A, Bottoff M R (2003) Tremorgenic mycotoxin intoxication with penitrem A and roquefortine in two dogs. J Am Vet Med Assoc 222 (1), 52-3, 35 PubMed.
  • Boysen S R, Rozanski E A, Chan D L, Grobe T L, Fallon M J, Rush J E (2002) Tremorgenic mycotoxicosis in four dogs from a single household. J Am Vet Med Assoc 221 (10), 1441-4, 1420 PubMed.
  • Naud√© T W, O'Brien O M, Rundberget T, McGregor A D, Roux C, Flaoyen A (2002) Tremorgenic neuromycotoxicosis in 2 dogs ascribed to the ingestion of penitrem A and possibly roquefortine in rice contaminated with Penicillium crustosum. J S Afr Vet Assoc 73 (4), 211-215 PubMed.
  • Puschner B (2002) Mycotoxins. Vet Clin North Am Small Anim Pract 32 (2), 409-19 PubMed.
  • Walter S L (2002) Acute penitrem A and roquefortine poisoning in a dog. Can Vet J 43 (5), 372-374 PubMed.
  • Lowes N R, Smith R A, Beck B E (1992) Roquefortine in the stomach contents of dogs suspected of strychnine poisoning in Alberta. Can Vet J 33 (8), 535-8 PubMed.
  • Hocking A D, Holds K, Tobin N F (1988) Intoxication by tremorgenic mycotoxin (penitrem A) in a dog. Aust Vet J 65 (3), 82-85 PubMed.
  • Puls R, Ladyman E (1988) Roquefortine toxicity in a dog. Can Vet J 29 (7), 569 PubMed.
  • Arp L H, Richard J L (1979) Intoxication of dogs with the mycotoxin penitrem A. J Am Vet Med Assoc 175 (6), 565-566 PubMed.

Other sources of information

  • Konnie Plumlee (ed) (2004) Clinical Veterinary Toxicology. Mosby Inc., pp 231-281.
  • Puschner B (2004) Penitrem A and roquefortine. In:Clinical Veterinary Toxicology. KH Plumlee (editor). Mosby, St Louis.
  • Peterson and Talcott (eds) (2001) Small Animal Toxicology. W B Saunders Company, pp 593-599.
  • Gary D Osweiler (1996) Toxicology. Williams and Wilkins.

Organisation(s)


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