A heartbroken pet dog dug a grave for a dead cat that used to be his best friend.

Footage shows the Aspin pooch named Donut diligently digging the dirt so his owner could place the dead moggie in their backyard in Nueva Ecija province, the Philippines on August 29.

Pet owner Frederick Gamit said the two would always sleep together until they woke up one morning and the cat was already lifeless.

He said: ‘The two were very close, they always play and sleep together. The cat used to be a stray and then slept in our backyard. We let it live here and became friends with our dogs.

Frederick added that he didn’t know why the cat suddenly died but it might have been sick as it refused to eat days before it was found dead.

He said: ‘We think the cat was sick. We have given it food the night before but when we woke up it was already dead. It was very sad.’