You & Your Pet by Dr. Wise

Rhode Island Veterinary Medical Association 11 South Angell Street #347 · Providence, RI 02906 (877) 521-0103 (866) 277-0238 Toll-Free ·Fax

My dog recently drank antifreeze and nearly died.  With intensive care, my veterinarian was able to save my pet.  Will you tell readers about the dangers of antifreeze?

You were extremely fortunate that your veterinarian was able to save your pet.  It was very lucky that you noticed something was wrong with your dog and took him to your veterinarian so quickly, when he was in the early stages of toxicity.  Unfortunately, most pets who drink antifreeze do not survive.

Ethylene glycol is used in automotive antifreeze.   Because of the sweet taste, dogs and cats readily drink it.  It is very toxic and small amounts cause severe and often fatal kidney damage.  Less than a teaspoon of antifreeze can kill a seven pound cat, and less than two ounces can kill a twenty pound dog.

In the early stages of toxicity, which occurs minutes to hours after drinking antifreeze, animals become depressed, ataxic (poor balance, wobbly gait), and begin vomiting.  This is the stage when treatment can save lives.  Irreparable kidney damage occurs within days if there is no medical intervention.  Later, signs include loss of appetite, depression, ataxia, weakness, vomiting, increased thirst and urination, and even convulsions.  Most animals die after falling into a coma. 

The key to a successful outcome is early recognition and treatment.  There is a test available to check for blood levels of ethylene glycol, which is accurate if the animal is tested within 24 hours after drinking antifreeze.  If caught early, treatment is usually successful, and the animal often has no permanent kidney damage.  If treatment is not started until the later stages of toxicity, the animal usually does not survive.  Treatment includes giving medicines to make the animal vomit up the antifreeze, giving drugs that counteract the effects of ethylene glycol, and using intravenous fluids and other supportive care.   The prognosis depends on both how early treatment is started and how much ethylene glycol the animal has consumed.

Increasing public awareness of how toxic ethylene glycol is will reduce the number of animals who have exposure to it, and awareness of how important early and aggressive treatment is will result in more positive outcomes.

My son and I winterized our cars last weekend.  My son insisted that we pen the dog and cat in the house and said that if they got into the antifreeze, they would probably die.  I went along with him and put the animals out of the way, but I really can't believe they were in danger.

I am glad you kept your pets away from the antifreeze because your son is right -- antifreeze is poisonous to animals.  You are not the only pet owner who is unaware that this common substance is a fatal attraction for dogs and cats.  

Just one teaspoon of antifreeze can kill an eight-pound cat while as little as one-half ounces can kill a 20 pound dog.  Even a less-than-fatal dose can cause serious damage.  The sweet taste of antifreeze is the crucial factor in the widespread incidence of poisoning.  Someone spills a little antifreeze on the ground.   A pet steps in it, licks its paws or takes a lick from the spill.  It likes the sweet taste and proceeds to lap up all it can find.  The antifreeze works quickly.  Within 30-60 minutes, the animal shows signs of depression, has a look of fear and becomes ataxic (stumbling).  Then vomiting is soon followed by paralysis, and within 6 to 12 hours, coma. 

At the first sign of distress -- or when you have the slightest suspicion that the animal has ingested antifreeze -- rush it to the veterinarian's office or an animal emergency hospital.  Ethylene glycol is the culprit in the antifreeze.   It metabolizes after ingestion to produce toxins which work on the central nervous systems and kidneys.  The quicker the animal is treated, the more likely it is to recover.  Clearly, prevention is the best course.  Keep animals out of the area when using antifreeze and make sure that any spills are washed away.

This information, prepared as a public service by the Rhode Island Veterinary Medical Association, answers problems Rhode Island veterinarians currently are seeing in their practices, as well as new developments in animal care.