Douglas, a four-year-old West Highland terrier, was dragged and mauled by a "stocky" dog at 6.30pm on June 18, suffering a bite on his neck and severe bruising.
Farnborough police are treating the matter seriously and are keen to track down the dog and its owner.
They are also urging owners of so-called "dangerous dogs" to be more responsible for their animals after the incident at the junction of Peabody Road and Queen's Road.
"It came haring up the road and got stuck into him," said Douglas' owner Stan Williams.
"The other dog had a massive head and had hold of him in his jaws, dragging him across the road.
"At first I didn't know if it was going for me or the dog. I would have thought it should have been muzzled with that sort of behaviour.
"A smaller dog would have been killed and, who knows, it could have been a kid."
Mr Williams said he was grateful to a woman passer-by who heard the commotion and rushed out to help pull the dog off.
Mr Williams said he thought Douglas' attacker was a mastiff-type Staffordshire bull terrier, and added that the young boy who was walking it could not control it.
Douglas had to be taken to a vet for treatment and was "very shaken" by the attack.
"He was quivering after it and the next day he didn't want to go out for his walk. We had to physically pick him up," added Pamela Williams.
Insp Phil Kedge of Farnborough police said dogs should not be given the opportunity to attack or scare the public and said not enough owners were aware of the Dangerous Dogs Act.
"The laws are there, but how many dog owners know the law themselves? Under Section 1 dangerous dogs have to be kept on leads and muzzled."
He said it was worrying to think what would have happened if a child had been attacked.
"We don't know what type of dog it was. We need to know who's the owner and what type of dog it was."
Anyone with information should call Farnborough police on 0845 0454545.
Stan Williams is pictured comforting Douglas as he recovers from the attack.