Cats.... so many cats!

[Nick Smith]

I'm wrapping up a deal on a 2 bed, 1 bath house for $55,000 in the Midwest. The rent will be bumped up to $700 a month. After accounting for the mortgage, insurance, taxes, cap-ex, vacancy, and property management (but self-managing), we see cash flow of ~$100 a month. The current landlord is in the flipping/realtor business, and wants to increase is cash on hand for more flips. He talked to the tenant about selling the property and bumping the rent up to $700 (from $650).  She understands she's been under market for rent, so she feels fine with paying more. She loves the house and is grateful because she has.... FIVE CATS.

If there were no tenant, I would probably go for a no pet policy, but she's there and wants to stay. She's willing to sign a 2 year lease. She's never been late and pays all of the bills. The cats are pretty gross. It smells like cat pee throughout the house. 

I'm prepared to replace all of the floor (kitchen, living room, bathroom to vinyl plank and bedrooms to carpet). I'm fine with a deep wash of the walls, priming, and painting. 

What other major damage from cats should I account for? I'll be sure to do a check-in list and any scratching damage on walls or wood trim. If the pee was so bad, could it "stain" the floorboards? Can these be bleached clean or is it typical to replace them? 

Obviously, I want/need the house to be safe, clean, and livable, but I won't be doing major renovations until she moves out. She understands this and would feel guilty if her cats did damage to brand new floors. The home passed rental inspection so the township is satisfied and the tenant is satisfied. Am I crazy to rent to a lady and her 5 cats?