Very hard to get rid of Guest, i persume your dog is peeing on the grass, some people i know have bought "rocks " for there drinking water,but i tried these to no avail,in the end we had to build a large pen for our dog and kept him of the lawn we had to put in a new lawn daunting task sorry you probably didn`t want to hear this type of answer hope it works out for you :~)))))

Not an easy problem to solve. Keep a watering can handy so you can dilute the acid in the urine which kills the grass. We had this problem with our old terrier. Early in the Spring we sowed grass seed ove rthe patches and now it is as good as new.

Hope this isn't silly but -take the dog a walk outside!