A court decision not to convict a New South Wales man who bashed a border collie puppy to death with a hammer has angered animal lobby groups.

Roland John Black, 35, has been put on a 12-month good behaviour bond with no conviction recorded after pleading guilty to one charge of animal cruelty and another charge of aggravated animal cruelty.

In Narromine Local Court on June 12, the aggravated cruelty charge was dismissed and he was ordered to pay court costs of $81.

Police say on Saturday afternoon, November 12, 2011 he drove to Dandaloo Road about 500 metres from the town of Narromine in western New South Wales and pulled over.

They say he got out of the car, hit the puppy with a hammer, then threw it against a power pole before driving off.

Local police were alerted to the incident on their Eyewatch internet page.

Officers who found the dead animal alerted Council Rangers and Black was charged.

Police say the puppy had earlier been taken to a Dubbo vet who offered to euthanise it for free because it was sick with Parvovirus.

Claire Fryer, a spokeswoman for People for the Ethical Treatment of Animals, which offered a $1,000 reward for witnesses to the attack to come forward, says it is disappointing Black did not get a jail sentence.

"Instead he's walked free from court without a blemish against his name" she said.

"The puppy was already sick but rather than offer it a humane death, this man took the suffering puppy out, threw it against a pole and smashed its head with a hammer."

She said it is disappointing that judges and magistrates often seem to impose the minimum penalty for animal cruelty offences.

RSPCA New South Wales chief inspector David O’Shannessy says the incident serves as a reminder to animal owners to listen to the advice they are given by registered vets.

"People who own animals have an obligation under the Prevention of Cruelty to Animals Act to get veterinary treatment if their animals needs it," he said.

Mr O’Shannessy says while he does not know the specifics of this case, magistrates have a range of options available when they sentence people for animal cruelty offences.