This toxin is a potent neurotoxin (LD50 332 μg/kg) with no known antidote.
Tetrodotoxin is produced by commensal bacteria which reside within the gastrointestinal tract of these organism. The toxin is then transferred into the liver and skin of the fish, where it resides.
Poisoning in dogs is usually associated with consumption of raw puffer fish, sea slugs or other marine fish, or inhalation or skin contact with poisonous toads. It is commonly reported in Japan, Gulf of Mexico and New Zealand.
Signs of intoxication are primarily asymptomatic in small doses, but neurological signs can occur within 1 - 3 hours post-ingestion, with symptoms such as paraesthesiae, dyspnea, ataxia, ptyalism and seizures have been reported, associated with a higher mortality rates due to respiatory and cardiac failure.
Symptoms include tremors, hyperesthesia, muscle fasciculation, seizures, nystagmus and diarrhea.
Diagnosis is based on history of exposure or presence of fish in vomitus. A definitive diagnosis requires chemical testing of vomitus or tissue sample testing taken from postmortem samples.
A differential diagnosis would include ciguatera poisoning.
Treatment involves decontamination and supportive therapy for seizures (e.g. diazepam, phenobarbital), tremors and muscle fasciculation. Severe cases will require induction of general anesthesia with thiopentone and artificial ventilation and aggressive intravenous fluid therapy.
An experimental monoclonal antibody against tetrodotoxin has been developed with purported efficacy against clinical symptoms in mice.
- Seaslug forum
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