The boy went into anaphylactic shock, where the mouth, throat and airways constrict, after being bitten by the snake in Condove, a town in Piedmont, on Sunday afternoon, Il Messaggero reported.
He was taken to Regina Margherita hospital in Turin, where he was put into a medically induced coma, although doctors said he is “out of danger”.
They said he was responding well to treatment and that his conditions were quickly improving.
Vipers are a family of poisonous snakes found across the world apart from Antarctica, Australia, New Zealand, Ireland, Madagascar and Hawaii.
Ambush predators, their venom is injected through their long, hinged fangs.
There are seven species of poisonous snakes in Italy, and they are all from the viper family.
In May, a couple in Florence found a boa constrictor, a non-poisonous snake, in their kitchen.