Ingesting antifreeze can have severe consequences for your dog’s health. We explain how this substance affects your body, how to identify its symptoms, and what to do in case of poisoning.

The dogs who have access to the garage of the house and the puppies, for their curiosity, are more likely to suffer poisoning antifreeze, consisting of ethylene glycol, a liquid substance, transparent, odourless, and somewhat sweet taste that is used mainly to avoid damage due to temperature changes in the cooling ducts of car engines.

The ingestion of a small amount of ethylene glycol is enough to cause severe damage to the dog: between 4 and 6 millilitres per kilo of weight, which is equivalent to a quarter of a glass of water for a dog of about 10 kg. Antifreeze containers are usually added with colouring substances to avoid household accidents. What attracts animals is its sweetish taste. 

Hence it is hazardous for your pet since they can lick it directly or after getting stuck to the legs after returning from a walk down the street. The ingestion can occur either because it can be spilt when throwing it into the car or because we leave the container open, but we must also consider that it can leak from car radiators to the ground.

How Ethylene Glycol Works in the Pet’s Body

After ingestion and absorption in the digestive system, ethylene glycol is metabolized in the dog’s liver through the enzyme alcohol dehydrogenase to different acids that cause acute damage to the kidney and central nervous system. 

In addition, another of its derivatives, oxalic acid, induces the formation of calcium oxalate crystals in the kidneys, worsening kidney damage.

Symptoms of antifreeze poisoning in dogs

The clinical signs of ethylene glycol poisoning in dogs are divided into three distinct phases as time passes since ingestion of the product. With a small amount, the animal can already suffer damage to the kidney and the central nervous system and even death, so it is vitally important to recognize the first symptoms to act quickly. 

The severity of the symptoms will be greater the more poison you have ingested.

Antifreeze Poisoning in Dogs

Phases of Ethylene Glycol Poisoning

Ethylene glycol poisoning manifests itself with different symptoms depending on the time that has elapsed since the animal ingested the product, and there are three phases in the intoxication process:

  1. Phase 1: symptoms appear between 30 minutes and 12 hours after ingestion. The animal presents anorexia, greenish vomiting, drowsiness, and ataxia (uncoordinated movement, as if it were drunk ). Also, you may have a fever and polydipsia (excessive urination), and polyuria.
  2. Phase 2: occurs between 12 and 24 hours after ingestion. The dog shows cardiorespiratory abnormalities, such as tachycardia and tachypnea. If the amount ingested is high, it can rapidly progress to a seizure and coma. Some animals experience some improvement before entering phase 3.
  3. Phase 3: signs of acute kidney damage appear between 24 and 72 hours, such as abdominal pain, profuse vomiting and diarrhea, depression, and oliguria (poor urine production). In many cases, animals that reach this stage do not respond to treatment and die.

Diagnosing Antifreeze Poisoning in Dogs

Although there are tests to detect the presence of ethylene glycol in an animal’s body, its availability is scarce, so the diagnosis is based on the recognition of symptoms and analytical and imaging tests. 

The most frequent alterations found in blood tests are elevated renal function markers (creatinine and urea), hyperglycemia, hyperphosphatemia, and decreased blood pH (metabolic acidosis).

In addition, calcium oxalate crystals can be seen in the dog’s urine, and an X-ray can detect an increase in the size of the kidneys and, on ultrasound, changes in the structure of the kidney, such as the “medullary ring sign.”

Treatment of antifreeze poisoning in dogs

The treatment of intoxication ng antifreeze or ethylene glycol in the dog should be initiated as soon as possible. However, the prognosis worsens considerably if the animal reaches the veterinarian in phase 2 or 3 of poisoning, where kidney damage is quite advanced in many cases, can be fatal. In the case of antifreeze poisoning, all actions must be carried out under veterinary supervision since monitoring in intensive care is necessary.

Suppose the ingestion of the product has occurred in the first two hours before the consultation. In that case, the dog can be induced to vomit to expel as much of the poison as possible and administer activated charcoal, thus avoiding the substance’s absorption.

The second line of treatment is to avoid metabolizing ethylene glycol in the liver to the acids that cause the most severe symptoms. This is achieved by blocking the action of alcohol dehydrogenase through the administration of ethanol (alcohol) or 4-methyl pyrazole, closely monitoring the function of the nervous system and kidneys.

Intravenous fluid therapy is necessary to protect the pet’s kidneys and restore acute damage. In the most severe cases, it may be required to put the animal on dialysis to filter the toxic substances present in the blood.