@Jerry422
At this point you are new to hosting and need all the good press you can get. My feeling is you need to use this experience as a learning curve, be as @Anonymous says and be a doormat, don't antagonize this guest by calling them out! It will do you more harm than it will the guest!
Suzanne, when we host, we are running a business! In most instances we are not helping people in times of crisis, we are letting them use our properties for a financial reward, and the trick in successful hosting is to minimize the risks that are attached to that financial reward.
Allowing pets does pose a high level of risk. Pet owners look on their pets differently to the way others do.
That German Shepherd that just knocked over your hall stand was not trying be destructive, it was just pleased to see his owner come back......that little 'bladder with 4 legs' that ran in from outside and piddled on your white rug was not trying to be destructive, that's what it does at home and the owner just accepts that this is what happens when you have a pet!
Suzanne, we have a pet, an Aussie Shepherd dog, here she is waiting for the next guest to arrive...

But I state in my listing description I do not allow pets. Our dog has a lovely nature, loves everyone and everything, but she is a known quantity.....we know where we stand with her.
I had one guest who asked if she could bring her two dogs. I asked her what sort of dogs were they and she said they were about the same as our dog. I thought about it for a while and figured it would be good company for our hound. When this woman arrived she arrived with two Burnese Mountain dogs each weighing about 70 Kgs and the pair of them destroyed our garden and frightened the bee-jesus out of our Betts. On leaving all she said was..."I hope the dogs were not too much trouble" and with that she was gone.

At that point I removed pet friendly from my description, that is not to say I won't take a pet, but if someone specifically asks I will asses the request and I certainly would not charge a figure for the pet.
By charging a pet fee you are doing two things.
1/......You are encouraging guests to do what you have experienced here and try to sneak the pet under the radar.
2/.....Because the guest has paid for the pet that entitles the pet to become a 'guest' and do what ever it likes.
Suzanne, as I said, learn from this experience and pull up the drawbridge with your pets policy. That way you will have at least got rid of one of your hosting risks.
All the best.
Cheers.........Rob
@Melodie-And-John0 @Emilia42 @Linda513 @Lorna170