Salma Hayek -- Dog Shot Dead

Salma Hayak's dog was shot and killed by someone who is very, very cruel.

Hayak's 9-year-old dog Mozart died a week ago ... found dead at her Washington state ranch with a bullet close to his heart.

Salma didn't reveal the tragedy until Friday night, saying "He was the most loving and loyal companion. He didn't deserve a slow and painful death."

Salma was incredibly close to Mozart ... she delivered him out of his mother's womb.