I need help with a pet policy violation

[Mic Nguyen]

I have a tenant who is moving out this Friday and It has came to my attention that the tenant has had a dog in my property when the lease specifically states that I do not allow pets because Im am allergic to dogs and because I just did a complete remodel on this property before the tenant moved in last year. What can I do? The tenant wants her deposit refunded but I believe she owes my money for at least a pet fee and to clean the house back up. Any advice would be greatly appreciated. Thanks