Little Boris was a 13-year-old Bedlington Terrier and his owner, Tony Wainwright, 54, had hoped the mut could “grow old” with the family.
He was said to have been to good health for his age before the suspected serpent strike.
The pet began suffering from unusual symptoms all of a sudden, with swelling on his leg, chest, jaw, and face.
Tony, from Newton, near Nottingham, took the pooch to see a vet and was given medication.
But it didn’t work, and after also trying out steroids the painful-looking symptoms continued to worsen.
The vet then drained the swelling and put Boris on morphine to ease the pain, but he had become so sick he stopped eating.
“I slept downstairs with him, and followed the vets orders,” Tory said.
“Myself and my partner were really pleased when the next day he seemed better, eating a bit and running across the lawn.
“But then he came back in and his body went into spasm, he was yelping and crying, so we rushed him back to the vets.
“We were there at 7.30am and it didn’t open until 8.30am. It felt like the longest hour of my life.
“The vet had a really big think over what had caused it, and could only conclude that the venom from a snake bite had got into his bloodstream.
“We wanted to give him a chance, and he stayed in the vets, and initially was reacting well.
“But when nurses tried to move him, he was in so much pain, we took the very hard decision to euthanize him.”
The news that Boris’ death may have been brought on by snake bite, possibly an adder, has been a shock for his owner.
He added: “I would never have believed something like that could happen.
“But then I found stories of other dogs and even humans being bitten and I felt that more people should know. If I had known, I would have taken him to the vets sooner.
“The area where I walk him is just behind my house, and has short grass surrounded by longer grass under trees, and there’s a pond, which is all the right conditions for these snakes.”
He continued: “Boris was a very inquisitive dog so it’s just the nature of the beast.
“I feel he has been stolen from me, in a way; he was 13 but in good health. He was really popular with all the dog walkers.
“I’ve had a couple of cards, one from the vets who treated him, to send their sympathies. Both the practice and the PDSA were brilliant with him.”
Chantel Litchfield, practice manager at All Creatures, said: “This is only the second case of a snake bite we have had, but it is becoming more common with people finding new places to take their dogs.
“Adders will go for the legs and face, and in Boris’ case it was his throat, which would have affected him more seriously.
“I am trying to make clients more aware, with posters and social media, and would advise people to report any changes, especially swelling or puncture wounds to their vet.”
An RSPCA spokesperson said: “Adder bites can be extremely dangerous to pets, particularly if the animal is bitten on the face.
“The bites can cause swelling, bleeding or fever, and dogs walked in adder habitats during spring and summer are more at risk.
“Animals with suspected adder bites should be kept as quiet and calm as possible, and examined urgently by a vet.
“Dogs are naturally very curious but if you see your dog near one we advise that you distract your dog away from the snake to avoid any injuries.”
They added: “If someone has been bitten, keep them as calm and quiet as possible, keep the bitten limb still and seek immediate medical help.
“If a person who has been bitten loses consciousness, call an ambulance.”