There's a newish Small Door in Bethesda that gets decent reviews. NOT Friendship Hospital (which is not Bethesda, but close enough you might be tempted to try it. Don't.)

If you're willing to leave Bethesda, VCA in Rockville is spectacular.

Bradley Hills Animal Hospital. Excellent with cats, dogs and ferrets.

But they will sometimes price gauge you for screenings that are not always necessary.

Please share your recommendations for vet practices in Bethesda, preferably independent rather than corporate.