I don't have any pets and I have already made an appointment to get it replaced. I was curious about what could be the cause so I don't ruin the replacement. I bought this car used on 01/30/2021 and I suspected the detailer used some type of detergent to clean the interior that the rear deck does not agree with( it was previously a rental car), but I still have the manufacturer's warranty so I hope they cover it.