The Risks of Antifreeze to Dogs

Antifreeze Toxicity in Dogs

In spring and fall, many people change their antifreeze mixture in cars to adjust to the temperature. Unfortunately, this seasonal ritual for auto owners often causes poisoning in thousands of dogs. Of all the poisonous dangers facing your dog, antifreeze is perhaps one of the most noxious.

Dogs like to lap up the deadly substance because it smells and tastes sweet. But even a few tablespoons can be lethal to your dog. Most brands of antifreeze contain the substance ethylene glycol, which is also found in air-conditioning coolants, brake fluid and in many color-film processing solutions used in home dark rooms. Little more than 3 tablespoons of the substance (45 milliliters) can be lethal to a 22-pound dog.

It is estimated that 10,000 dogs are poisoned each year by drinking antifreeze. Studies have shown that most poisonings occur around the pet’s own home because owners have not safely stored or disposed antifreeze.

Studies have also shown that ethylene glycol poisoning often occurs in the fall, winter and early spring, which coincides with the seasonal maintenance for cars. If you suspect that your dog has ingested even the smallest amount of antifreeze, contact your veterinarian immediately.

Why Antifreeze is so Dangerous to Dogs

Ethylene glycol is not dangerous by itself, but it becomes toxic after a dog has ingested it. When metabolized, the substance turns into several dangerous chemicals that can cause severe kidney failure. Ethylene glycol toxicosis (which is how veterinarians refer to the poisoning) is often fatal if not treated within four to eight hours.

In fact, about 80 percent of those dogs with kidney failure associated with antifreeze die. Immediate reaction is necessary to save your pet’s life. Unfortunately, many owners do not realize their pet has consumed antifreeze. They often become aware of the problem when their pet shows symptoms of kidney failure, which they may not attribute to poisoning. Depending on how much ethylene glycol their pet drank, signs may not show up for several days.

What to Look For

The poison is rapidly absorbed into a dog’s system and quickly affects the brain and spinal fluid. As a result, a pet may act “drunk” within 30 minutes to 12 hours after ingesting the poison, depending on how much was ingested.

Other signs to look for include:

• Nausea
• Vomiting
• Increased thirst
• Lethargy and depression
• Poor coordination progressing to coma

What to Do if Your Pet Drinks Antifreeze

Call your veterinarian immediately if you suspect your dog has consumed a product containing ethylene glycol! Timing is crucial if your pet is to survive; treatment after 24 hours following ingesting the poison is often futile.

Your veterinarian may recommend that you try to induce vomiting by giving him hydrogen peroxide before taking him to the hospital, especially if you’ve just seen your pet consume the poison.

What Your Veterinarian May Do

Once you bring your dog to the veterinary clinic or animal hospital, your pet will be evaluated. Besides a complete medical history and physical examination, your veterinarian will conduct several other tests, including:

• Blood test to confirm the presence of antifreeze.
• Serum biochemistry tests to determine if the kidneys are functioning properly and to detect electrolyte disturbance.
• Urinalysis to look for signs of calcium oxalate crystals. Ethylene glycol eventually breaks down to these crystals, which can block the flow of urine. However, calcium oxalate is only present 30 percent of the time and may not be found in the urine.
• Blood gas analysis to evaluate the presence of severe acidosis.

Your veterinarian may induce vomiting or begin pumping your pet’s stomach to remove the poison before it can be broken down into its toxic end-products. S/he may also administer activated charcoal to bind the poison, and give sodium bicarbonate if acidosis is severe. Fluid may be given intravenously to ward off dehydration.

In addition, your pet will be given an antidote and will spend several days in the hospital.

How to Prevent Antifreeze Poisoning in Dogs

Most poisonings occur around a pet’s home. By keeping containers of antifreeze and other products with ethylene glycol tightly closed and out of reach, you can prevent a potential tragedy. The most important thing you can do is to not allow your dog to roam unsupervised. Remember, by the time you notice something is wrong with your dog, it may already be too late. Other preventative methods include:

• Cleaning spills immediately with plenty of water.
• Using antifreeze products that do not contain ethylene glycol (such as Prestone LowTox® and Sierra®). These types of products use propylene glycol, which will also cause signs of drunkenness, but are not toxic (unless consumed in large quantity).
• Preventing access to areas, such as the driveway or garage, where ethylene glycol-containing products may be stored or spilled.

For more information on antifreeze dangers, diagnosis and treatment, please click on Dangers of Antifreeze Toxicity In-depth.