It depends on the thickness of the ice.If the ice is less than 4 inches thick, it is not safe for dogs to walk on.
Dark, slushy, or cracked ice is a sign that the ice is thin.If you see any of these signs, do not let your dog walk on the ice.
If your dog falls through the ice, stay calm and act quickly.Throw a rope or a long stick to your dog so they can grab it and pull themselves out.
Never let your dog walk on ice alone.Always supervise your dog when they are near ice. If you are unsure if the ice is safe, do not let your dog walk on it.
Dress your dog in warm clothing if they are going to be near ice.Bring a towel to dry your dog off if they get wet.
Ice can be very dangerous for dogs, as they can easily fall through and drown. Even if the ice looks thick enough, it may not be strong enough to support a dog's weight.
The American Kennel Club has more information about ice safety for dogs. The National Snow Dog Association also has resources on how to keep your dog safe on ice.