Is this a rental, or did you buy the property? If this is a rental, contact the landlord immediately! If you purchased the property, you may have recourses that you can pursue....contact the REALTOR you worked with (or a Real Estate Attorney).
Try one (or all) of these homemade solutions:
DIY (Cat) Stain and Odor Remover
3 natural homemade cleaners
Six Homemade Remedies for Dog Stains and Odors
If all else fails, speak with a local stain removal professional and/or get some quotes for replacing the floor. I don't envy you with this... good luck. (Please share whatever ends up working!)