@Hazel12 If you read the Air BNB Contents Policy in the Help Center, you will find that both hosts and guests can state opinions and perceptions without censure. It works both ways. Even the best of pups, (being a dog owner myself) can be messy, so I always assume that I will need to be prepared for the worst. Perhaps the host needs to provide more access to cleaning materials and your response to her will prompt her to do so.
I suggest you don't waste your time on fighting this review. As you continue to travel with Air BNB, and I hope you will, your reviews will accumulate as positive ones. Good luck