Oprah met with some of the heroes going out and searching for the missing in her community after devastating mudslides this week ... including a few 4-legged ones.

O posted a vid talking to search and rescue workers in Montecito Saturday, which included some awesome dogs ... especially her new pal, Mondo.

She wrote, "People not the only heroes in our little community. Met some 4 legged ones too. Searches continuing today."

The rescue worker also gives Oprah a lesson in how the canines operate and how they differ.

DEVASTATION

As we reported ... Oprah's community's been ravaged by the mudslides -- including the home of her neighbor, Jeff Bridges.

At least 18 people have died and 6 are still missing.