Ingesting a Small Amount of Antifreeze Causes Kidney Failure in Dogs
Pound for pound, antifreeze is the heavyweight of poisons seen in small-animal veterinary hospitals. It has the highest fatality rate of any toxin seen in pets. The antidote must be administered quickly.
Dogs tend to find antifreeze (ethylene glycol is the active ingredient) in puddles on the ground that has dripped out of a car radiator. Since it is sweet-tasting, dogs might drink it. (Animals walking across open puddles may also clean it off their feet when grooming.)
Part of the problem with antifreeze that makes it such an effective killer is the incredibly small amount needed for it to be lethal. For dogs, the lethal dose is a little more than 3 cc per pound. For a 20-pound dog, that is like half a shot glass. It is astonishing that although antifreeze has been around since the 1920s many people are still not aware of its hazardous potential.
The key to successful treatment of antifreeze poisoning is early recognition. Treatment must begin as quickly as possible.
Ethylene glycol causes kidney failure very quickly. Clinical signs appear within 30 minutes of ingestion and dogs act as if they are drunk. They stagger, exhibit slow reflexes and vomit. After a few hours they may appear to have recovered. After 12 to 24 hours, the signs of full-blown kidney failure emerge and little can be done.
For successful treatment, therapy must be initiated within about five hours. Prognosis is good in dogs receiving the antidote (called fomepizole). With early recognition of the problem and timely therapy, many dogs can be saved.
The best cure, however, is never letting your dog ingest antifreeze.
Originally published in AKC Family Dog in “Ask Dr. Kevin” by Kevin Fitzgerald, DVM.