I have been dog sitting for 5 days for 2 Bernese Mountain dogs. [View all]

[Paper Roses]

They are huge peeing and pooping machines.
I know my back lawn will be a wreck come warm weather. Do any of you fine folks know of a product that I can spray or spread on the now frozen grass(or later when it thaws) that will neutralize the urine? Of course I keep it picked up but there is going to be a mess of dead grass come spring.
Thanks for any hints.

This sitting was for a good cause but I'll not do it again.
My poor kitty has been locked on the second floor for days. She is really mad at me.