Market conditions plus risk.

Risk is driving higher requirements for eligibility. Higher fico scores, bigger deposits, higher rents. Animals in your units causing expensive damage that you cant control and you have no say in keeping them out is risk. Another item of risk is the chance of a tenant refusing to pay rent for years and you having zero ability to remove them. Lots of landlords have fled the rental market in seattle because of market conditions here turning old rental units into now owner occupied units.

All those items lead to an increase in rents as landlords try to mitigate real and potential future losses. So yes, shitty pet owners can cause higher rents.