De-icing salts are poisonous to cats and particularly hazardous because they may walk on the substance and then ingest it when grooming.
In the UK, council (local authority) gritters use rock salt. The material is spread across the road to de-ice the road and to prevent it icing up. It is also used on pavements (sidewalks).
In 2010, in the UK, the RSPCA said it had received almost 250 calls about cases involving cats and dogs becoming seriously ill and in some cases dying because of rock salt and antifreeze.
People use thawing salts around their home in freezing weather in order to keep the paths manageable and safe. In homes where they let their cat out there seemed to be a distinct possibility that the cat will walk on this material, pick up the substance on their paws and then lick it off.
One of the great weaknesses of the domestic cat with respect to poisoning is that they are fastidious groomers and will lick their paws and their coat which inevitably leads to ingesting any poisons picked up in those areas.
The signs of toxicity with respect to thawing salts which is a strong local irritant are: lesions in the mucous membranes and on the pads of feet, gastrointestinal ulceration, vomiting, diarrhoea, burns to the mouth and throat and excessive salivation and drinking.
Rock salt or thawing salts contain the same ingredient as table salt, sodium chloride but it also contains harmful chemicals such as magnesium which burn.
The time of year when these chemicals are used is coming up and therefore I think people who regularly use rock salt outside should take due consideration of the potential dangers, if they look after a domestic cat.
Emergency first aid is recommended if a cat is poisoned by rock salt. The mouth and exposed areas of skin should be flushed with cold water and water administered orally.
I can see difficulty in getting water into the mouth and down the throat of a cat. I would suggest that after flushing the exposed areas as best one can then an emergency visit to a veterinarian would be in order.
It goes without saying, of course, that the sooner a cat is treated by a veterinarian the better his or her chance of recovering and in the case of antifreeze of surviving. Antifreeze, as you know, kills cats. All of it should be non-toxic. Bitterants should be added.