Tenant lied on Pet Form with a breed we don’t permit, what now?

[Account Closed]

So, our new tenant signed on for a year lease without a dog at first but with intention to get a dog. We informed them ahead of signing of the breeds we don’t allow. 
Our tenant finally got his new puppy which he is claiming is a Boxer and it is written on the adoption form but with the pictures they sent in, it is clearly a Pit Bull and we don’t allow it. I called the SPCA with the id number and adoption confirmation and found it is truly a Pit Bull. 
Where do I go from here? Give them a timely manner to get out 3-6 months (they have 10 months left on lease), evict right away, or let it stay until end of lease and not sign with them again?

[Nathan Gesner]

Quote from @Account Closed:

My process is to serve them with an unauthorized animal violation, fine them $200, and require them to remove the animal within 72 hours and pass an inspection. If they don't do it, the lease will be terminated. Of course, this is all fully disclosed in the lease and my policies.

I also have a policy against animals owned for less than one year (puppies, kittens, or newly adopted animals) because those are the most likely to cause damage.

EDIT: to be more precise, I would not allow the tenant to stay with the animal. Either they get rid of the unauthorized animal, or they all get out.