Ethylene glycol, more commonly identified as a component of antifreeze, is a very serious toxin to cats. While it's most commonly known for being a coolant in vehicles, it can also be found in brake fluid, toilet winterizers for recreational vehicles or summer homes, heat exchangers and portable basketball hoops. Once ingested, antifreeze can be absorbed within about 40 to 60 minutes. Antifreeze and cats are a very toxic combination — even a very small ingestion can result in severe signs of antifreeze poisoning and potentially death. Here's what to do if you suspect that your cat drank antifreeze.

What to Do If Your Cat Drank Antifreeze

Once absorbed, antifreeze is metabolized by the body into multiple toxic substances which result in the development of physical symptoms and acute kidney failure. An ingestion of 1.4 ml of antifreeze per kilogram of body weight may result in death. Therefore, if your cat drank antifreeze, or if you have a high suspicion that they've ingested some, you should take your cat to a veterinarian immediately.

If the cat has antifreeze on its paws or fur, it should be washed off to prevent any continued exposure while traveling to the vet for evaluation. It is also very important to remember to bring the container or label for the antifreeze with you to the vet so that they know exactly what was ingested. Some forms of antifreeze are less potent than others.

Symptoms of Antifreeze Ingestion & Poisoning

Following antifreeze ingestion, symptoms develop rapidly, and for simplicity, they can be divided into early and late symptoms. Early symptoms are related to ethylene glycol, which is a very potent alcohol; these symptoms can be seen approximately 30 minutes to 12 hours following ingestion. The early symptoms of antifreeze in cats include:

  • Vomiting
  • Nausea
  • Depression
  • Weakness
  • Loss of balance
  • Increased drinking and/or urination
  • Rapid breathing

Late symptoms, which are the result of the multiple toxic products accumulating in the blood stream, develop at approximately 12 to 24 hours in cats and are related to development of acute kidney failure. These symptoms could include:

  • Severe lethargy
  • Not eating
  • Vomiting
  • Oral ulcers
  • Salivation
  • Seizures
  • Producing only small amounts of urine

If you notice any of these early or late symptoms, be sure to pay a visit to your vet as soon as possible.

Diagnosis

Rapid diagnosis of antifreeze poisoning is key. Diagnosis is normally based on witnessed ingestion or known recent access to antifreeze, and it can also be based on recognition of the early symptoms of toxicity. In some cases, the use of a special light called a Wood's lamp will show glowing residue on the face and paws, urine or vomited stomach contents. Residue could suggest exposure as a florescent dye is added to antifreeze.

Blood and urine test results can further support any suspicions of ingestion. The combination of antifreeze and cats can cause diluted urine, the development of a specific type of crystal in the urine, and decreased bicarbonate and increased phosphorus levels in the blood. All of these signs can occur in the first few hours after a cat has consumed antifreeze. There are commercially available tests for detection of ethylene glycol antifreeze in dogs, but unfortunately, they are not accurate in cats as cats develop toxicosis at much lower levels than dogs. If available, running an ethylene glycol level at a human hospital could be a more reliable way to evaluate for the unfortunate mix of antifreeze and cats. In the late stages, acute kidney failure and elevation of kidney blood values develop secondary to the antifreeze ingestion. Sadly, once this occurs, the prognosis for recovery is grave.

Treatment

If your cat drank antifreeze, treatment with antidotes such as fomepizole or ethanol could prevent production of toxic metabolites and promote excretion by the kidneys. If you live in an area where it's available, dialysis can also be performed with high success rates in the early stages of exposure. For cats, the window for treatment following antifreeze ingestion is very narrow. Treatment can be successful if initiated within three hours of ingestion. If you saw your cat drink antifreeze, or if you're suspicious of an ingestion, it is very important that you seek emergency care immediately. Some cats that are successfully treated for antifreeze ingestion may have residual kidney damage secondary to the toxicity.

Preventing Antifreeze Poisoning

Antifreeze and cats do not mix well — prevention is the key! The best way to prevent medical complications related to antifreeze and cats is to keep cats indoors and keep all chemicals put away so that there is no risk for ingestion. If your cat has access to a garage or workshop area where chemicals and automotive supplies are stored, everything should be kept closed. Keeping up with recommended routine vehicle maintenance to prevent any antifreeze leakage, and fixing and cleaning up any fluid leaks from your car, can also help to prevent exposure. Some states require the addition of a bittering agent to decrease the attraction to antifreeze as it naturally tastes sweet, but cats with limited access to water may still drink it out of thirst. There are also some types of antifreeze that do not contain the potent ethylene glycol and are considered "safer" and less toxic. The main ingredient in these products in propylene glycol.

Antifreeze and cats can be a deadly combination, so ultimately, prevention is the best treatment. Keeping cats indoors and away from chemicals can ensure your cat's safety. However, if you do find that your cat drank antifreeze, seeking immediate vet care could save your cat's life.

Dr. Jessica Seid Dr. Jessica Seid

Jessica Seid is an emergency veterinarian practicing in the New England area. She is a graduate of the North Carolina State College of Veterinary Medicine and has been in the field for more than a decade. When she's not helping patients, she enjoys spending time with her husband, daughter and French bulldog.

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