Clifford Clarke was outside his home in Clubmoor, north Liverpool, when the dog attacked on Saturday evening.
Merseyside Police found his body and were confronted by a dog that was described by officers as “out of control”.
Armed police destroyed the animal outside the pensioner’s home in Richard Kelly Close. The breed of the dog has not yet been established.
Two women, aged 27 and 28, were arrested on suspicion of an offence under the Dangerous Dogs Act, 1991.
They were rearrested and questioned a day later on suspicion of manslaughter before being bailed.
It is understood that the dog belonged to the house next door to where Mr Clarke, who had celebrated his 79th birthday only last week, lived.
A post-mortem examination established that he had died from multiple injuries consistent with a dog attack.
Locals said there were three dogs in the neighbouring property, two of which were described as calm and the other more aggressive.
One resident, Susan Carson, told Sky News it was a “big dog” but she was unsure of the breed.
“People used to moan about it barking in the back,” she added.
Ms Carson described Mr Clarke, whom she said she had known since 1986, as “a nice bubbly person”, who “got on with everyone”.
She said he had lived in the house all of his life and used to work as a hospital porter.
A single bouquet of flowers were laid against the wall at the front of Mr Clarke’s