Tenant lied and has a dog on first month of lease -Texas

[Mak K.]

I am from Texas. When application was made tenant was I am not going to to have my puppy with me so do not need pet fee or application etc.

First month and I find a dog in the house which is 50lb. Now she claims it’s a service dog because his husband is vet and she should be legally allowed to keep the dog and does not need pet fee or pet deposit or monthly pet rent. 

She is arguing about the law. 

What does law say? If you allow service dog, you sure need to pay a deposit , application fee and monthly pet rent correct? How do I deal with her and is it a lease violation? I would be glad to kick her out if she doesn’t follow lease and lies