@Anna16649
You have every right as owner to charge the guest the replacement costs for the item. In your booking the charge for pets is way too low. Depending on the length of the stay, and when we initially allowed pets, our daily charge was $25 per pet. Then there should be an extra one time charge for cleaning, sanitizing, and deodorizing, $75 for 2 to 7 days and $150 for 8 plus days.
Accidents do happen, but in your property, the Guest is 100% responsible for their pets, this is not debatable or a negotiation.