Laser pointers are dangerous to animals just like they are to humans. Laser pointers can damage eye sight when misused. Therefore, yes, they can be dangerous to dogs if someone points the laser in the dogs eyes. One should always use a laser pointer carefully; not pointing it at any eyes: both humans and animals alike.
The light from a laser pointer can damage optic nerves and tissue. We know that scientifically. As with any light emitting toy, you have to use common sense. Don't shine it in the dog's eyes, don't make them chase it into furniture, don't lead them out into traffic with the red dot. Be responsible for your pet, and don't blame the laser for being a tool.
As with any light, if you shine a laser pointer directly into the retina of any animal, it can cause permanent damage to them. As it is already, dogs are at risk for some diseases, such as glaucoma. We should not use these devices on our loving pets that could make the issue even worse. Yes, these devices are definitely dangerous to dogs, and to anyone if used improperly.
I can not fathom what the harm would be to a dog to play with a laser pointer with them. They have fun while they are doing it, just don't be a moron and shine it into their eyes or some other such idiocy. They will be fine in the long run.