As a devoted dog owner, you're always on the lookout for potential hazards to your pet's well-being. One danger that's often overlooked, yet very common is antifreeze poisoning in dogs. While antifreeze is a common household item, especially in colder months, its active ingredient, ethylene glycol, can be lethal to your pet. Symptoms occur in stages but often include incoordination and disorientation, lethargy, vomiting, lack of appetite, increased thirst, increased or decreased urination, hypothermia, seizures, coma, and sudden death.

What is antifreeze?

Antifreeze is a liquid commonly used in vehicles to prevent the engine and other components from freezing in cold temperatures. It's also used in various household and industrial applications.

The main ingredient that makes antifreeze so effective, yet so dangerous to pets, is ethylene glycol. This chemical has a sweet taste, which unfortunately can attract dogs and lead them to ingest it.

Ethylene glycol is highly toxic and can cause severe poisoning in dogs and cats, leading to kidney failure, coma, and sudden death.

Understanding what antifreeze is and why it's harmful is the first step in preventing accidental ingestion and ensuring your dog's safety.

Unfortunately, antifreeze toxicity is associated with mortality rates of up to 70% in dogs and up to 100% in cats.

How do dogs get exposed to antifreeze?

Accidents happen, and dogs are naturally curious creatures. Whether it's a leak from your car, a spill in the garage, or even residue on the ground, dogs may come into contact with antifreeze without you even realizing it. The sweet taste of ethylene glycol can entice them to lick or ingest the liquid. Additionally, antifreeze can be found in some household items like de-icers, solvents, and even some paints.

Various measures have been implemented to mitigate the risk of toxicosis in animals. Nowadays, numerous antifreeze products are formulated with a bitter additive to discourage ingestion. Additionally, certain antifreeze solutions are marketed as safer alternatives, containing propylene glycol as the primary component, which is significantly less toxic than ethylene glycol. These advancements aim to enhance the overall safety and well-being of animals.

By recognizing the risks and choosing safer alternatives, you can take preventive measures to keep your pet safe and minimize the chance of accidental ingestion of antifreeze.

Stages and symptoms of antifreeze poisoning in dogs

Within just 30 minutes, ethylene glycol is rapidly absorbed into the body, with peak levels in the bloodstream occurring within 3 hours. Having food in the stomach can slow down absorption. Following ingestion, it quickly spreads throughout the blood and tissues which leads to the signs and symptoms.

Stage 1: Within 30 minutes to 12 hours

If your dog has ingested antifreeze, the first symptoms usually appear within 30 minutes of ingestion. These early symptoms can include vomiting, lethargy, and incoordination. Your dog may also display excessive urination and thirst. Seizures and low body temperature are other signs to watch for.

Stage 2: 12 to 24 hours

Stage 2 typically occurs 1-2 hours after ingestion, although it can occasionally occur as late as 12-24 hours post-ingestion. Around 12 hours after ingestion, you might notice a deceptive improvement in your dog's condition. However, this is when internal damage intensifies. Elevated heart rate, rapid breathing, and dehydration are common symptoms of antifreeze poisoning at this stage.

Stage 3: 36 to 72 hours

If not treated within the first 24 hours, the poisoning progresses to a critical stage. Your dog's kidneys may become swollen and painful, leading to kidney failure. Additional signs may include severe lethargy, lack of appetite, lack of urine production, and worsening seizures. In severe cases, your dog may progress into a coma.

Overall symptoms of antifreeze poisoning:

  • Lethargy
  • Anorexia (lack of appetite)
  • Disorientation
  • Ataxia (loss of control over bodily movements)
  • Nystagmus (abnormal eye movement)
  • Miosis (constricted pupils)
  • Muscle fasciculations (muscle twitching)
  • Seizures
  • PU/PD (Increased frequency of urination and drinking)
  • Tachypnea (rapid breathing)
  • Cough
  • Dyspnea (difficulty breathing)
  • Hypothermia (abnormally low body temperature)
  • Hypersalivation (excessive drooling)
  • Nausea (excessive lip licking)
  • Vomiting and/or diarrhea
  • Oral ulcers
  • Distended abdomen
  • Abdominal pain
  • Oliguria (reduced urine output)

It's important to keep in mind that not all dogs will exhibit all these symptoms, and their manifestation can vary based on the amount of antifreeze ingested and the time elapsed since ingestion. Always consult with your veterinarian immediately if you suspect your dog may have ingested antifreeze.

dog with antifreeze poisoning

What to do if you suspect antifreeze poisoning?

If you think your dog has ingested antifreeze, time is of the essence. The first step is to get your dog away from the source of the antifreeze to prevent further ingestion. Next, call your veterinarian or an emergency pet poison helpline immediately for guidance. Do not induce vomiting unless explicitly instructed by a veterinary professional, as this can sometimes worsen the condition.

Given the narrow window for effective treatment—ideally, within a few hours of ingestion—it's imperative to bring your dog to the emergency vet right away. Your vet will likely perform tests to help confirm antifreeze poisoning and may administer an antidote, such as fomepizole or ethanol, to counteract the toxic effects. Immediate veterinary attention can significantly improve your dog's chances of survival and minimize long-term kidney damage.

How is antifreeze toxicity treated in dogs?

The treatment involves two main steps: specific therapy and supportive care.

As ethylene glycol is rapidly absorbed within hours of ingesting, inducing vomiting may not be effective. Furthermore, it is important to note that activated charcoal does not significantly bind with ethylene glycol and is therefore not recommended.

Specific therapy

The primary goal of specific therapy is to prevent the toxic products from forming in the body and eliminate any remaining ethylene glycol. This typically involves administering an antidote, such as fomepizole or ethanol, which act as competitive inhibitors and block the conversion of ethylene glycol into its highly toxic metabolites.

Additionally, your dog may receive intravenous fluids to help flush the toxin out of their system. In severe cases, hemodialysis or peritoneal dialysis may be recommended as a means to remove ethylene glycol and its metabolites from the blood.

Supportive care

Supportive care aims to manage symptoms and prevent further complications until the body can eliminate the toxic substances. This may include providing intravenous fluids to prevent dehydration and maintain electrolyte balance, as well as addressing other symptoms such as seizures, low body temperature, antiemetics (for vomiting), and kidney disease.

What is the prognosis for dogs with antifreeze poisoning?

The prognosis for dogs after exposure to ethylene glycol, the toxic ingredient in antifreeze, varies based on several factors. The prognosis is generally worse if:

  • Large quantities of the toxin have been ingested.
  • There's a delay in administering the antidote.
  • Blood tests show azotemia (high levels of nitrogen-containing compounds) or oliguria (reduced urine output).

The best chance for survival comes when treatment with the antidote fomepizole is initiated within 5 hours of ingestion. On the other hand, if there's a delay in treatment beyond 8-12 hours, especially with significant amounts of ethylene glycol ingested, the outcome is unfortunately often fatal.

For dogs showing azotemia upon admission, antidotal therapy alone is usually insufficient for survival. However, combining this with hemodialysis—a procedure to remove waste and excess substances from the blood—can improve the prognosis.

How long does it take to show signs of antifreeze poisoning in dogs?

Signs of antifreeze poisoning in dogs can show up as early as 30 minutes after ingestion, with peak symptoms typically observed at 12 to 24 hours post-ingestion. However, the manifestation of symptoms can vary based on the amount of antifreeze ingested and the time elapsed since ingestion.

How to test for antifreeze poisoning in dogs

Testing usually involves blood and urine tests. These tests can reveal elevated levels of ethylene glycol and its metabolites in your dog's system, as well as any resulting kidney damage. There is a specific test for ethylene glycol but needs to be performed before any treatment to avoid false positives.


Antifreeze poisoning is a severe and potentially fatal condition in dogs. Understanding the stages and symptoms of antifreeze poisoning can help pet owners recognize early signs and seek immediate veterinary attention. By taking preventive measures, choosing safer alternatives, and being vigilant about keeping antifreeze out of reach, we can protect our pets from this life-threatening toxin. Remember, if you suspect your dog has ingested antifreeze, time is of the essence—seek veterinary care immediately for the best chance at a positive outcome. So always keep an eye on your pets and take necessary precautions to avoid any accidents. Your dog's life may depend on it.