A months-long dispute over two pets, a dog and a cat, ended in a retired army officer shooting dead his neighbour and then himself, in Pathum Thani on Monday morning.

Police were called to a housing estate in tambon Khlong Sam about 7.30am. They found two bodies, one Col Jaruchart Jarupan aged 64, and the other Saowagul Sasadoh, 53. The woman's 30-year-old son was also injured, with a bullet wound to his left hand.

Witnesses told police the army retiree and his female neighbour had a long-running dispute and had argued over their fence that morning. The man then went inside. He came out with a gun, walked over to the woman's house and shot her repeatedly.

She was hit by five bullets, police said.

The colonel was found dead in front of her gate with a gunshot wound in his left temple.

The retiree's wife said her husband and their neighbour had been arguing for about six months over their pets. She saw her husband collect his gun and leave and then heard many gunshots. She ran outside and saw her husband fire a shot into his own head.

The dead woman’s son said he rushed to the front of the house after hearing the gunshots, and the colonel shot at him as soon as he saw him. He was hit in the hand.

He said the dispute between the two families started after the retired officer's cat crossed their fence into his property, where they keep a pet dog.