Mr Culpin, of Endeavour Hills, admits the last-ditch act was "weird" but thinks it shocked the dog into stopping its attack.
The incident happened last month when Mr Culpin neared a woman walking her dog.
"The dog jumped on to my dog and latched its jaws around his neck and was trying to twist and kill him," he said.
"I flung down and was trying to push my body weight between them, trying to open its jaws. I was punching the dog because I really thought Lachie was going to die and when it didn't budge, I just bit it on the back of its neck.
"It happened so fast. I don't know why I did it, it was just instinct, a reaction, but it was weird. The dog just stopped and looked back at me in shock like it didn't know what just happened," he said.
Mr Culpin suffered deep wounds to his hand and a painful back injury trying to protect his three-year-old pet. He said the attack had cost him more than $1200 in vet and doctor bills.
"I don't blame the dog, but the woman walking it was not strong enough to control it," he said.
"If that had been a child, they would have died."
Casey Council has since told Mr Culpin the dog that attacked him must now be muzzled when in public.
The computer technician said only now can he see the funny side of being known to have bitten a dog.
"I can't help but laugh now," he said.
(Herald Sun - June 9, 2012)
