Donnie was bitten on the face and taken straight to a vets for treatment while slipping in and out of consciousness.
The pup was given anti-venom medication and antibiotics but his health deteriorated and he died on Saturday morning.
Ali Mathers, Logan's mother, said: "We are absolutely heartbroken and just can't believe it. We want to stop another dog being hurt." The family have been left with a £4,000 bill for their dog's treatment.
Wildlife experts have warned of the dangers of adders, Britain's only venomous snakes, which are eme...