I highly doubt it. The cats should continue to use the litter box as long as it's kept clean. I really see no reason for a cat to try to mark over a dogs pee. As long as everyone is spayed or neutered there shouldn't be any territorial marking to begin with.
My cat is smarter than your honor student.
Stop Dog Fighting ~ Neuter Mike Vick!
~ RIP Timmy ~ May 2009 - November 6th 2009