The main question is what is in the snow. Snow by roads, driveways and pavements may carry de-icing products, vehicle fluids or hidden debris. Antifreeze can be deadly even in small amounts. Steer your dog away from treated and unknown patches, and carry fresh water rather than using snow as their drink.
If you know or suspect they swallowed antifreeze, call an emergency vet or animal poison service immediately. Do not wait for symptoms or try to make them vomit yourself. If they ate a de-icing product, tell the vet what product and how much may have been consumed. The winter paw-care article explains how to handle grit on the feet after a walk, but it cannot make contaminated snow harmless.
Snow in a known untreated yard poses a different chemical exposure than a roadside pile, but you may not know what is hidden beneath it. Watch for vomiting, lethargy or a change in drinking, and ask your vet if snow eating becomes persistent or your dog seems unwell. Wipe salt or grit from paws after a walk so they do not lick it off at home.
Today, choose a cleared safe route and make water available. Do not ask your dog to practise ignoring a potentially toxic patch while standing beside it.
Sources: Dogs Trust on winter walks and clearing grit from paws, VCA on antifreeze poisoning and urgent response, VCA on cold-weather chemical hazards.