There is an alternative to a muzzle. The OutFox Field Guard was developed in Northern California to protect dogs against dangerous grass seeds we have here called foxtails. We bought the field guards as protection against foxtails, but we have found they also work to stop our corgis from "grazing". Our smaller corgis wear size small, and our larger corgis wear size medium.

Here's the OutFox website: https://outfoxfordogs.com

And here's the product on Amazon