Unauthorized pet lease violation occurs when a tenant brings in a pet without prior approval from the landlord. This can cause significant damage to the property, and the landlord can face various legal issues. In such a case, the landlord has the right to terminate the lease and request the tenant to vacate the premises. It is essential to understand the lease agreement thoroughly before bringing in a pet to avoid any unauthorized pet lease violation. Always seek approval from the landlord to avoid any legal consequences.