It depends on the snake. In Australia if your dog gets bitten by a tiger snake, dugite, death adder, taipan or any of the brown snakes, it needs anti-venene asap or they die pretty quickly.
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we use the word moron quite a lot in Australia
We have taipans, one of the most dangerous snakes in the world. They are highly venomous, bite repeatedly, inject lots of deadly venom, and are highly aggressive snakes that go after anything that moves.
We also have cute little bunny rabbits that kill taipans.