A Virginia man who chased and killed his neighbour's two Labradors had engaged in "vigilante justice", a court has heard.

Stephen Nichols Cook, 68, from Christianburg, Virgina was charged with multiple offences over a violent confrontation between him and local man, Arthur Hamrick, in November of last year.

Cook became enraged after Hamrick's dogs, Yancey and Maggie May, attacked and killed his pet cat after intruding on his land. Cook pursued Hamrick in his vehicle and pulled up alongside his pickup, got out with his dead cat in one hand and a pistol in another.

After muttering something to Hamrick, Cook pointed his gun at the two dogs who were sitting in the back of the pickup and shot them.

During the court hearing, Assistant Commonwealth's Attorney Dean Manor said Cook had chosen "vigilante justice" instead turning to police or pursuing other non-violent means.

"From a public safety perspective you can't go around pointing guns at people. And you can't shoot companion animals regardless of what's happened to yours," Judge Randal Duncan ruled, stating that Hamrick would have been within his rights to shoot Cook after he pointed his gun at him during the tense stand-off.

Cook was found guilty of two misdemeanour offences, including brandishing a firearm and recklessly handling of a firearm. Judge Randall imposed a 12-month jail term, with nine months suspended, and issued a $2,500 fine for each offence.

Witnesses at the hearing explained how the tensions came to a boiling point between the two neighbours following years of disagreements. In 2012, Cook claimed he saw his cat caught in the mouth of one of Hamrick's dogs and asked him to restrain them in the future.

"Revenge or anger is not a justification. That's why we have laws," Manor said.