ઢોરના ચાવ્યામાં કુચો પડે, પણ લોકના ચાવ્યામાં કુચો પડે નહીં.

ḍhōranā cāvyāmāṁ kucō paḍē, paṇa lōkanā cāvyāmāṁ kucō paḍē nahīṁ.

Literally: What cattle chew leaves pulp, but what people chew leaves no pulp.
What it means: Being chewed upon by public gossip destroys a person's reputation completely without leaving anything behind.

Also said as

ગુજરાતી કહેવતસંગ્રહ (Gujarati Kahevat Sangrah) (1921) · read from the scan by machine — the Gujarati itself is unchecked · English is machine-made and nobody has checked it yet

Heard it differently, or know we've got the sense wrong? Tell us — that is exactly the kind of correction this needs.