Police are investigating and are urging pet owners to keep them inside

The man gave letters to Altona North residents saying their pets

A man is believed to have shot and killed three cats and injured another in a rampage in west Melbourne.

It appears that the gunman dropped off threatening letters to several homes in the Altona North area before the shootings, telling residents their pets would die, according to Seven News.

Veterinarian Dr Nadia Wong said soon after a three-year-old white cat was brought to her after it was shot in the hip with a .22 calibre shotgun.

A man is believed to have shot and killed three cats and injured another (pictured) in a rampage in west Melbourne just days after delivering letters to residents warning them their pets will die

Veterinarian Dr Nadia Wong said it was not long after the letters were handed out that a three-year-old white cat was brought to her with a wound from a .22 calibre shotgun to it's hip (right)

The cat surprisingly survived but has to learn how to walk again, she said.

Although it is unknown why the man is targeting pets, Dr Wong said 'using guns is not the way to (threaten and kill off pets).'

'It creates fear and anger in the community and I hope we don't see this again.'

Another cat died in the same area after being shot twice and a third was killed in nearby Point Cook.

The cat surprisingly survived but has to learn how to walk again (pictured)

Hobson Bay Vet Clinic posted on Facebook that they had also seen a similar case and that veterinarians believe there are three other cases of family cats being targeted.

RSPCA spokesperson Daniel Bode told Seven News the shootings were 'shocking acts of cruelty.'

The shooter could face a $75,000 fine and up to two years in jail if caught.