A rifle-toting female rancher is on trial in B.C. provincial court, charged with unlawfully shooting a neighbour's dog after it chased her cattle.

The trial that began in B.C. provincial court Tuesday will determine whether Ruth Robinson was justified in shooting her neighbour's 45-kilogram Leonberger, a European giant dog breed.

Robinson operates a ranch at Sharpe Lake, located about 20 minutes south of Bridge Lake on the Bonaparte Plateau.

Const. Matthew Hartwig testified Tuesday that Clinton RCMP were called by Robinson and her neighbour, Wayne Beck, after the shooting in June 2011.

The remote area is an hour and a half drive from Clinton.

"The allegation is Ruth Robinson unlawfully killed a dog," Crown prosecutor Alex Janse said at the beginning of the trial. The offence is listed under the Criminal Code.

Robinson is expected to defend her actions based on a section of the Livestock Act that allows owners to protect animals. The act reads "a person may kill a dog if the person finds the dog a) running at large and b) attacking or viciously pursuing livestock."

"She didn't shoot at the dog while it was in and around her cattle," Hartwig said during cross-examination.

The trial was adjourned until May 30 because Beck was unable to attend Tuesday to testify.

Hartwig said he and his partner arrived at the property on June 5, 2011, to interview Robinson.

Robinson told him she'd "heard the dog barking, looked and saw Mr. Beck's dog in her cattle pen," the court heard.

Hartwig said Robinson told him that she went to retrieve a .22-calibre rifle from her home and proceeded to "dispatch" the dog.

The dog was no longer in the cattle pen when Robinson shot it, Hartwig said.

In retaliation, Beck threatened to shoot Robinson's dog and reportedly fired a shot in the air, Hartwig testified.

Robinson had all the necessary firearm permits, the Mountie told the court. Beck's gun was not properly licenced.

Hartwig said he helped Beck onto Robinson's property so the rancher could load the dead dog into the back of his pickup.

During cross-examination, Robinson's lawyer, David Hughes, asked Hartwig to draw a comparison between a police officer shooting a suspect in a crowded mall and Robinson shooting a dog in a crowded cattle pen.

"Would you agree it's better to shoot at a subject when they're stopped and away from others?" Hughes asked Hartwig.

Robinson is expected to tell the court her story when the trial continues in May.