That’s the problem with pets! Had a cat years ago that scratched all the pieces of a very nice new leather living room set and tried to start using my speaker grills as a scratching post. The cat and owner were politely asked to find another good loving home!
Dissolve baking soda and water in a spray bottle and mist the area. The baking soda will get rid of the smell. Sprinkle pepper around the speakers. It will keep the dog from doing it again. Hopefully you have carpet because pepper on a hard floor wouldn’t be so feasible.