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Antifreeze Toxicosis


  • Antifreeze poisoning occurs when pets drink antifreeze containing ethylene glycol.
  • The liver quickly breaks down ethylene glycol into toxic products that can lead to kidney failure and death.
  • Even a small amount of antifreeze can be fatal to dogs and cats.
  • Antifreeze poisoning is a medical emergency, and early treatment is crucial.
  • Signs include: staggering, vomiting, increased drinking and urination, and seizures.
  • Diagnosis is generally based on the results of blood and urine tests.
  • Treatment may include the induction of vomiting, medications to prevent the absorption and metabolism of ethylene glycol, and fluid therapy.

What Is Antifreeze Poisoning?

Most antifreeze solutions contain high levels of ethylene glycol, an ingredient that, once metabolized, is extremely toxic to dogs and cats. Pets are often attracted to the liquid because of its sweet taste. Even small amounts can be lethal to animals. A cat that walks through spilled antifreeze and then licks its paws may ingest enough to be fatal. As little as 2.5 tablespoons of antifreeze could kill a 20-pound dog.

Once ingested, ethylene glycol is quickly broken down in the liver to other substances that can lead to kidney failure and death within 12 hours to a few days. That’s why antifreeze ingestion is a medical emergency. If you suspect that your pet has consumed antifreeze, contact your veterinarian immediately.

What Are The Signs Of Antifreeze Poisoning?

The signs of antifreeze poisoning vary, depending on the amount of antifreeze the pet drank and length of time since ingestion. Initially, pets may stagger or walk like they are drunk. Other signs include:

  • Lethargy (tiredness), depression
  • Nausea, salivation (drooling)
  • Vomiting (often the fluorescent green color of antifreeze)
  • Increased drinking
  • Increased urination

As time progresses, signs may include:

  • Rapid breathing
  • Seizures
  • Little or no urination
  • Coma

How Is Antifreeze Poisoning Diagnosed?

Antifreeze poisoning is generally diagnosed based on the results of blood and urine tests. However, as kidney failure sets in, these tests may be less accurate. Free-roaming pets that have signs consistent with antifreeze ingestion should be treated as soon as possible.

How Is This Condition Treated?

To be effective, treatment needs to be initiated as soon as possible after antifreeze ingestion. If your pet is seen within an hour of consuming antifreeze, the veterinarian may induce vomiting and possibly anesthetize the animal to flush out the contents of the stomach. They may also administer a liquid solution of activated charcoal to help prevent further absorption of the ethylene glycol.

If it has been longer than an hour since ingestion, the veterinarian will most likely give your pet a medication to help prevent the liver from metabolizing the ethylene glycol. The pet may also be placed on intravenous fluids and other medications to encourage excretion of the toxic substances produced during metabolism of ethylene glycol.

Once kidney failure has begun, it may be difficult to save the animal because the damage from antifreeze is often irreversible.

How Can I Protect My Pet From Antifreeze Poisoning?

There are a number of steps you can take to prevent your pet from drinking antifreeze:

  • Do not allow your pet to roam the neighborhood freely.
  • Use antifreeze containing propylene glycol, which is less toxic than ethylene glycol.
  • Do not allow your pet access to the area when you are draining radiator fluid.
  • Clean up all antifreeze spills immediately.
  • Store antifreeze containers out of the reach of pets.
  • Check your car for antifreeze leaks frequently.