@Meredith45, you can write a review that just reports what you found.
It should be rather like a newspaper story: stick to facts, avoid speculation and accusations.
"The cabin was not as clean as most guests leave it. There was food left out in bowls on the floor. We found dog hair on many surfaces and what appeared to be slobber on the sofa. The dog hair and slobber was not present when the guest checked in, and no one visited the property after the guest but before we discovered the dog hair."
Assuming you have photos to bolster this information, there is little to debate. You do not accuse them of anything. You merely report what you found. Future hosts can draw their own conclusions.