The pit bull involved in the Moama drowning tragedy will not be put down after police found the dog was trying to save the nine-year-old boy who survived the ordeal.

The dog "Buddy" was seized by Murray River Council on Thursday at the request of police after it mauled the nine-year-old boy in the shallows of the Murray River.

The boy had survived an attempted drowning, allegedly at the hands of his mother, before he was confronted by the dog.

Buddy allegedly mauled the boy, and his mother.