Inheriting tenants - verbal agreements

[Bruce Chang]

We have a tenant that was given a verbal agreement from the previous landlord that a dog was permissible on the premises only until it passed away.  Tenant claimed they were depressed without the dog even though there was no evidence it was a comfort/emotional support animal. We are changing the carpets in the home and come to find out, the dog has probably peed all over the carpet in the past causing the pad underneath to disintegrate.  The carpet is very old so we are not planning on suing to recapture any of the costs, but we have a few questions:

1.  The original lease states that no pets are allowed.  Is the verbal agreement still valid?  Can we now reinstate a no pets policy and enforce the original lease?

2.  Can we ask for a pet deposit?  Old landlord only had a $500 deposit which is nothing compared to how much a uncontrolled dog can damage the property.