Ice melt works by mixing in with the frozen water and lowering the freezing point of the water/ice. Typically, people use salt to melt the ice/lowering the freezing point. The problem with the salt products is it can make the feet really dry, or dogs can lick it and either upset their stomach or burn their tongues. If your dog eats an excessive amount of salt to melt ice, it can make him/her really sick – although it would be really strange for a dog to actually eat that salt.
Regular ice melting products use some kind of salt: sodium chloride, potassium chloride, magnesium chloride, calcium chloride, calcium carbonate, or calcium magnesium acetate. A bunch of fancy names for different kinds of salt. The new, so-called pet safe ice melting products are made with urea. Urea is a nitrogen based product, the ingredients are a lot like what goes into nitrogen fertilizer. Interestingly, urea is also made by the body, a breakdown product from protein digestion that is excreted in the urine and feces.
The problem with ice melt products is they aren’t well regulated, so unless you turn the package over and read the ingredients, if they even list the ingredients, you can’t be 100% sure the pet safe products really are safe.
Options to keep your babies safe: use booties, warm water foot bath when you get back inside, place towels on the ground to walk over, or, if your dog is little enough, carry your pup across the salty area.