Blowfish ingestion (Tetrodotoxin toxicity)

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What is it?

Dogs exercising along the beach or river bank may eat blowfish, toad fish or puffer fish which have washed ashore or been discarded by fishermen. Once ingested these fish release a neurotoxin, called a tetrodotoxin which can cause paralysis in pets and people.

What causes it?

There are several species of fish such as blow fish, puffer fish, toad fish and other marine creatures (such as blue-ringed octopus) which contain a tetrodotoxin that can cause paralysis. Depending on the geographical location, dogs can come across some of these marine species if found dead along the beach or waterways.

Depending on the amount ingested, the toxin affects the nervous system, causing progressive paralysis which can affect the pet’s breathing and can sometimes be fatal. Sometimes the pet may vomit up the fish after eating it, reducing the extent of clinical signs.

What animals are at risk?

Inquisitive dogs are the most commonly affected species. Blowfish may be washed ashore after stormy or rough weather, or can be left behind on jetties or on the beach or riverbank if accidentally caught by fishermen.

What are the symptoms?

Dogs may vomit up the blowfish soon after eating it which may reduce the risk of toxicity.

The onset of symptoms can vary from immediately to occurring anything up to 8-12 hours from ingestion, and can include:

  • Vomiting
  • Dilated pupils
  • Weakness and wobbliness when walking
  • Trembling and salivation
  • Progressive paralysis including difficulty breathing

  • If you have been walking your dog on the beach or riverbank, and notice dead blowfish around, the red flags for blowfish toxicity can include vomiting, salivation and strange behaviour such as weakness or trembling.

  • What first aid can I do?

  • If your pet vomits, check the vomit for a blowfish (and if possible bring this with you into the vet to aid identification of the toxin).
  • Keep your pet calm and seek urgent veterinary attention.
  • If your pet stops breathing, you can also start rescue breathing (mouth to nose breathing) enroute to veterinary attention.

  • How is the condition diagnosed?

    The diagnosis of blowfish toxicity is frequently based on the dog having been observed eating a dead blowfish or having been exercised in an area where blowfish may be present. If the dog vomits, or is made to vomit by the vet, then the diagnosis can be confirmed through visually sighting the blowfish remains.

    How can it be treated?

    Depending on the extent of clinical signs and the time since possible ingestion of the blowfish, your vet will often induce the dog to vomit to remove the fish from the pet’s gastrointestinal tract. A gastric lavage (stomach pumping) may also sometimes be performed to flush out the stomach contents to reduce the chance of toxin absorption, or administration of activated charcoal can also be used to reduce the toxin absorption. Your pet will be closely monitored in the vet hospital including often having a blood test, and other supportive treatment when needed including intravenous fluids and breathing support.

    How can I prevent it?

    If walking your pet at the beach or river, keep an eye out for blowfish or other puffer fish species washed up or lying discarded on the shore. Restrain your pet on a leash and keep them away from any blowfish. It might also be thoughtful to remove any dead blowfish from the area into a bin to reduce the risk to other pets.