Winter woes: Why melting ice is dangerous for dogs
Winter is quickly approaching, and it won’t be long before roads, sidewalks and driveways are covered with chemicals used to melt ice. If dogs aren’t eating them, they’re at least walking through or playing in them. Unfortunately, ice melts pose a problem for dogs with both oral ingestion and dermal contact. There are many brands of ice melts on the market, but the major ingredients are sodium chloride, potassium chloride, magnesium chloride, calcium salts or urea-based material. Before suggesting ice melts to your clients, get the cold hard facts below:
Mild ingestions of sodium chloride lead only to gastrointestinal upset such as vomiting and diarrhea. Large ingestions, however, can lead to sodium toxicosis. A dose of 4g/kg of sodium chloride can be lethal to dogs as they develop hypernatremia with central nervous system signs, dehydration, tachycardia, tachypnea and hyperthermia.
Increased intake of potassium—as seen with large ingestions of potassium chloride salts—is unlikely to produce sustained hyperkalemia unless a dog’s renal excretion is otherwise impaired. Potassium chloride, however, is a severe irritant and can cause gastrointestinal irritation to the point of hemorrhagic vomiting or diarrhea.
Ingestion of ice melts containing magnesium chloride can be irritating and result in gastrointestinal upset. In addition, hypermagnesemia can occur with very large ingestions, but is unlikely to occur unless the dog has renal disease.
Calcium salts (calcium carbonate, calcium chloride and calcium magnesium acetate)
Calcium salts are the most severe irritants in ice melts. Ingestion of calcium salts can cause severe gastrointestinal signs as well as local irritation from dermal (skin and paws) contact. Large ingestions of calcium salts are unlikely to increase serum calcium concentrations because a number of other factors are needed to absorb the calcium.
Urea-based ice melts are generally the ones labeled as safe for use around pets. Ingestion of urea usually leads to salivation and mild gastrointestinal irritation. Large ingestions may result in weakness, tremors and methemoglobinemia.
Any ice melt has the potential to be hazardous. In general, most ice melt exposures are limited to gastrointestinal upset and local dermal irritation, but there is potential for more serious, life-threatening side effects. It’s important to educate veterinary practice clients on the potential risks of exposure and inform them of proper storage and use recommended on the package label so that exposures can be avoided. The golden rule is to use the smallest amount necessary to melt the ice.
Caley Chambers, a 2015 DVM candidate at University of Minnesota’s College of Veterinary Medicine, is an extern at Pet Poison Helpline.
Pet Poison Helpline is based out of Minneapolis and available 24 hours, seven days a week for pet owners and veterinary professionals who require assistance treating a potentially poisoned pet. The staff provides treatment advice for poisoning cases of all species, including dogs, cats, birds, small mammals, large animals and exotic species. Pet Poison Helpline’s fee of $39 per incident includes follow-up consultation for the duration of the poison case. Pet Poison Helpline is available in North America by calling 800-213-6680. Additional information can be found online at petpoisonhelpline.com.