The federal laws described above provide the minimum level of protection that a tenant can receive.
State law affects the rights of tenants in two principal ways.
A state may pass legislation giving protection to elderly or disabled tenants, for example. State courts may also interpret common law doctrines concerning the contractual relationship between the tenant and the owner of the property being rented that will determine if a tenant can retain a companion animal in the rented unit. The person is essentially deemed to have waived his claim by inaction. In some cases, even if the lease in question has a specific prohibition against keeping companion animals, a court may permit the tenant to keep the animal if the tenant can prove that the landlord knew about the presence of the companion animal for a long period of time and did not previously tell the tenant that he required the tenant to remove the animal or give up their rented accommodation. The operation of this doctrine should not encourage a person to acquire a companion animal in violation of a lease provision.