Yes, Walking on tiles or marble floors can potentially injure a dog's leg, particularly if the dog is not accustomed to the surface or if the surface is slippery. To prevent this, ensure that your dog is comfortable and has good footing before allowing it to walk on these surfaces. Make sure their paw pads do not have any cracks, and trim their nails.

Mostly in summer they sleep on floor/tiles because of heat. No worries but in winter the tiles might make issues

Thanks ☺️

But keep him on the other floor also as it is good for his legs . Because 24×7 on tiles floor can cause damage to his legs.

Yes we take him for playing in open ground

No. The problem arises when there is lack of calciy and vitamins.

Tiles and non grip or slippery floors are not good for Labrador, as they tend to develop a hip issue. Please look for Hip dysplasia in internet. As you said, playing outdoor, then it's good.