Sodium monofluoroacetate

From Dog
Tasmanian native Pademelons killed by 1080 poison[1]

Sodium monofluoroacetate (1080; Tenate) is a highly potent and toxic rodenticide poison used primarily for vermin control[2].

Fluoroacetate is also a toxic component of poisonous plants found in Australia, South Africa, South America and India.

In the USA and UK, sodium monofluoracetate is used to control rodents in areas of restricted access, such as ships, sewers and warehouses and coyotes the use of fluoroacetate-impregnated carcasses or collars on livestock. In Australia and New Zealand, pests such as rabbits, wallabies, goats, wild pigs, deer and possums are controlled with the use of baits based on apple, carrot or grain. Aerial sowing is used to control large or remote areas[3].

This drug is a colorless, odorless, tasteless, water-soluble chemical that is highly toxic to all mammals, most particularly dogs which are more susceptible than most other animals, with lethality occurring after consumption of less than 0.1 mg/kg[4].

Fluoroacetate is metabolized to fluorocitrate, which blocks the tricarboxylic acid cycle, and in dogs, this toxin targets the nervous system, resulting in a massive depression of neuronal energy production[5]. Sodium fluoroacetate acts by inhibiting energy production in most cells of the body. An indirect effect of the energy blockade is a depletion of available calcium, which also plays a role in clinical manifestations of fluoroacetate toxicity[6].

The main target organs affected are the central nervous, respiratory and cardiovascular system. This normally induces metabolic derangement that includes alteration in transaminase, calcium and glucose levels apart from acidosis and renal failure[7].

Dogs usually become intoxicated from off-lead scavenging in bushland and national parks where 1080 baiting occurs. Inadvertent consumption of dead rabbits and foxes that have consumed the bait, where the toxin remains active for many hours[8].

Clinically affected dogs show rapid neurological symptoms of muscle tremors, frenzied running, urinary and fecal incontinence, ptyalism and seizures, and die within 60 minutes of consumption of toxin[9].

Death is usually due to respiratory failure, but cardiac abnormalities are also noted prior to death such as arrhythmias, ventricular fibrillation and finally cardiac arrest[10].

Diagnosis is based on history of exposure and clinical signs. A definitive diagnosis requires toxicological analysis of stomach contents, gastric lavage fluid and vomitus[11].

A differential diagnosis would include strychnine toxicity. Fluoroacetate convulsions cannot be induced by noise or touch, and the time of onset for symptoms is longer than with strychnine.

The treatment of 1080 intoxication remains problematic, with no proven antidotes available.

Emetics such as apomorphine are contraindicated if clinical signs are present due to potential arrhythmias and convulsions the drug may induce.

Therapy in dogs with minor symptoms include induction of general anesthesia with thiopentone and halothane maintenance, followed by gastric lavage and adsorbents (activated charcoal, 0.5 g/kg) are recommended.

Prognosis is grave if clinical signs are severe[12].

References

  1. Habitat Advocate
  2. Egekeze JO & Oehme W (1979) Sodium monofluoroacetate (SMFA, compound 1080): A literature review. Vet Human Toxic 21(6):411-415
  3. ACGIH (1991) Documentation of TLV’s and BEI’s, 6th Edition
  4. Hugghins EJ et al (1988) Tissue fluoroacetate residues in prairie dogs dosed with low-level sodium monofluoroacetate. J Assoc Off Anal Chem 71(3):579-581
  5. Eason C (2002) Sodium monofluoroacetate (1080) risk assessment and risk communication. Toxicology 181-182:523-530
  6. Inchem.org
  7. Clarke DD (1991) Fluoroacetate and fluorocitrate: Mechanism of action. Neurochem Res 16(9):1055-1058
  8. Gooneratne SR et al (1995) Persistence of sodium monofluoroacetate in rabbits and risk to non-target species. Hum Exp Toxicol 14(2):212-216
  9. Goh CS et al (2005) Sodium monofluoroacetate (Compound 1080) poisoning in dogs. Aust Vet J 83(8):474-479
  10. Godoy HM & del Carmen Villarruel M (1974) Myocardial adenine nucleotides, hexose phosphates and inorganic phosphate, and the regulation of phosphofructokinase activity during fluoroacetate poisoning in the rat. Biochem Pharmacol 23:3179-3189
  11. O'Hagan BJ (2004) Fluoroacetate poisoning in seven domestic dogs. Aust Vet J 82(12):756-758
  12. Tourtellotte WW & Coon JM (1950) Treatment of fluoroacetate poisoning in mice and dogs. J Pharmacol Exp Ther 101:82-91