The hardwood floor turned black after being soaked in dog urine

It must be a reaction caused by immersion in water.

Generally speaking, a small amount of water does not need to be ignored at all, the floor has a certain moisture-proof function, if a large amount of water is ingress, it is best to use a vacuum cleaner (dry and wet kind) to blot dry, and then use a fan to dry the composite floor, which generally has a strong anti-soaking function.

Solid wood flooring also depends on the manufacturer and quality.

You can call the manufacturer for consultation.

After a large amount of water intake, the ground should be dried as soon as possible, otherwise the water will be soaked in the floor for a long time will make the floor expand and deform, and when the temperature is suitable, it will cause a large number of microorganisms to multiply, making the floor rotten and black, and the floor can only be replaced at this time. When the amount of water is small, the edge strip should be removed immediately and dried with an electric fan and hair dryer for rapid precipitation.

Dog urine is usually acidic, and its acidity is even much worse than acid rain, so it will have a corrosive effect on wheels, solid wood floors, and porcelain floors.

There is no way to do this, just pay attention, although dog urine will have a corrosive effect on the floor, it will generally be disposed of immediately and will not appear in the situation that the landlord said. If it turns black, there is no way, it is good to be able to buy the same model and the same model of the floor to replace it.

Use a sponge dipped in cooking oil and wipe patiently to repair. If it takes too long, it can be partially removed.

For solid wood floors, it is best to wipe oily maintenance products regularly. There is a layer of grease on the surface of the floor, which plays a certain role in isolation.

This one... Hard.

Sanding first, then painting the floor.

It's already dark, either replace it or dry it properly.