Kurera imbwa nomukaka mangwana inofuma yokuruma.

Zvinorehwa

Kunyange ukaitira munhu zvakanaka zvose, haazivi kuti angazokutadzira here mangwana.

What it means

Even after treating someone with nothing but kindness, there is no guarantee they will not turn against you.

Word for word

Raise a dog on milk, and tomorrow it wakes up biting you.