She probably never house broke him or neutered him. Male dogs even after being neutered do tend to still mark their territory. Also white dogs get those tear stain things. You can minimize it some with special wipes and conditioners etc but it just happens. Small breed dogs also are stubborn and hard to housebreak. My last dogs a few years ago were chihuahua and they were fine going potty outside except in snow or rain they refused so had to use the wee wee pads in the winter time but at least they went on the pads like 95% or more of the time. Housebreaking is the hardest thing but it helps to start early, get a crate that looks unusually small and cruel to most people, just barely big enough to stand and stretch and turn around, as they turn they should be brushing against the sides of the crate. Put bedding and toys and stuff in crate. Crate train them by leaving crate open and putting exciting things they like like a special toy or treat that they only get there and no where else. Gradually start closing door for a few minutes at a time staying in their line of sight then increasing the time and leaving the room etc. you want them to learn crate is good and safe and that you’re always coming back. Do not free feed them. Set up a schedule. Feed then within twenty minutes go potty and stay outside with them until they go and then lots and lots of praise like a crazy person like you just won a lottery and then back inside, not necessarily in their crate, they can be loose but keep an eye on them especially when they are puppies and a small breed like coco. They need to learn outside is for potty and inside is for play and cuddles and food and whatever else. If they just want to play outside and don’t go potty back in their crate and try again in 20 minutes.