Looking for some landlording advice

[Mazi Rodd]

This is my first post so please go easy on me. Bit of a back story, we have been living in a duplex and house hack it for around 3 years now. The whole time we have been house hacking, we have had the same tenants. They are great tenants, not to noisy, pay on time and are nice people to be around. In this I feel that we have gotten a bit too comfortable with each other over the years. Are tenants have always had pets (cats two, and lizard or two), so they pay a monthly fee for each pet. Which is great because more money right? Last winter they asked if it was ok to have a puppy. As per are previous experience with how clean they kept their other pets, we agreed that it would be fine as long has they cleaned up after the dog in the yard. We added another pet fee & went about are lives. Over time the cleanup in the yard starting to lose its vigor as it once had. Today while mowing the lawn, I either walked or mowed multiple dookies in the Midwest summer heat. I hit that never again feeling/ semi bowling anger. Instead of tempestuously confronting them (both parties where not home) I decided to ask around the forms for advice on how to approach this? While writing this post I realized that hindsight is 20/20. We should have had, in clear writing are expectations on this & maybe added an amendment in their lease other than the current pet fee structure. Any advice is appreciated and thank you for reading this long rant.