Every year dogs around Australia are poisoned and killed by dead puffer fish washed up along the coast, withmany pet owners unaware of how quickly a pleasant beach walk can turn deadly.
While there are no collated national figures on the number of dogs that fall victim to puffer fish poisoning each year, veterinarianAndrew Byrne says he alone has treated "half a dozen or more" cases of such poisoning indogs within the past 18 monthsat his clinic in northern Tasmania.
Each of thosedogs had, according to their owners, come into contact with a dead puffer fish immediately before they fell sick.
Two of themhad such dramatic reactions to the toxin of the fish that they died before they arrived at Dr Byrne'sclinic in St Helens.
"By the time they got into the car and to the clinic from wherever they were … the dog was no longer with us," Dr Byrne said.
"It didn't take them long to stop breathing."
He said most dog owners were not aware of the "extreme"toxicity of puffer fish and all the owners of the poisoned dogs he had treated had beensurprised by how easily their pets' lives had been threatened.
'Among the most toxic poisons known'
Puffer fish, also known as toadfish and blowfish, along with their longer-spined relatives theporcupine fish, are found all the way around Australia's coastline.
The potentially lethal toxin they contain —tetrodotoxin — isfound on their skin andinternal organs.
According to Animal Emergency Service, tetrodotoxin is approximately 1,200 times more poisonous than cyanide and a lethal dose of it is smaller than the head of a pin.
University of Tasmania marine ecologist Professor Graham Edgar says the toxinis "among the most toxic [natural] poisons known".
"That's across everything —snakes, spiders, whatever," ProfessorEdgarsaid.
"Within a toadfish, there are some parts that are actually edible and some parts that aren't.
"[But] you'd have to have a death-wish to go exploring there."
Deadly 'tasty treats'
Dr Byrne says it is common for dogs in coastal areas to encounter dead puffer fish.
"If puffer fish arepulled up by anglers they tend to be dropped on the wharf or in the boat, or just discarded," hesaid.
They are also often seen washed ashoreon beaches around the country, where many coastal residents walk their dogs.
"So they're there, they smell like fish [and] for a lot of animals that's a worthwhile tasty treat," Dr Byrne said.
He said some dog breeds seemed more likely to chew on a dead puffer fish than others when given the chance.
"The ones that I've seen tended to be English staffies, which tend to put their mouths on anything, and other curious dogs like labradors," he said.
Diagnosing 'in the dark'
For a vet, it can bedifficult to diagnose puffer fish as the cause of a dog's poisoning, Dr Byrne said.
"I've never pulled one out of a dog, and I've never found one in the mouth of a dog," he said.
"So a lot of the stories [of poisoning by puffer fish]are straight from the owners' mouths regarding what the dog was doing just before it got itself into a lot of trouble …incoordination and breathing issues, and what have you.
"We treat those animals like we would treat any poisoning [when]we don't know what [poison] it is."
Treatment includedgiving the animals fluids and activated charcoal "to bind up any poisons internally".
This treatment worked for the "four or five" dogs believed to have been poisoned by puffer fish thatarrived at Dr Byrne's clinic alive, as they all pulled through.
Puffer fish facts
In Australia, there are more than 60 species of puffer fish, which belongto the Tetraodontidae family.
But the term 'puffer fish' is also oftenused more generically, to include porcupine fish, whichin some casesare also lethallypoisonous.
Not allthe puffer fish-poisoned dogs that Dr Byrne has seen actually swallowed tetrodotoxin.
"So they were poisoned in a totally different fashion."
While scientific reports oftetrodotoxin passing througha puffer fish's spines do not seem to exist, onescientific article describes the case of an aquarium curator who developed symptoms of tetrodotoxin poisoning after handling a dead porcupine fish's internal organs, and thenbeing pricked by its spines.
With dogs, once the tetrodotoxin enters the body, it acts quickly andsigns of poisoning —including vomiting, excessive drooling and panting —appear within minutes.
Symptoms may then progress to trembling, unstablewalking, muscle tremors, paralysis, coma and then death.
Dr Byrne said dog walkers mustto be on the lookout for puffer fish all year round and familiarise themselves with the symptoms of tetrodotoxin poisoning.
"It'snot quite like snake bites where … they're definitely seasonal, andwe know all there is to know about snake bites, virtually," he said.
"Puffer fish are one of those rare things that just come up randomly."
For dog owners looking to keep their petssafefrom puffer fish poisoning, DrByrne recommends keeping themon alead.
"This is not a bad idea anyway because there's certain birds and wildlife in our sand dunes that don't really need dogs bothering them," he said.
And to dog owners who have already seen their pet chew, lick or roll on adead pufferfish his advice is simple:
"Get straight to the vet because you don't know how serious it's going to be."
For further information call the Animal Poisons Helpline on1300 869 738 or gotoanimalpoisons.com.au/news/pufferfish-and-your-dog
