Symptoms Of Antifreeze Poisoning In Dogs And Cats

by on March 30, 2011

Ethylene glycol is the active ingredient in antifreeze, which is used in the cooling systems of automobiles.  It is also found in hydraulic fluid, solar collectors, automotive brake fluid, and liquid rust inhibitors.  Ethylene glycol is toxic to all creatures, including humans.  However, it is typically dogs and cats that account for the majority of cases of antifreeze poisonings.  In fact, it is the most common cause of poisonings of dogs and cats in the United States.  It only takes one to two teaspoons of ethylene glycol to poison a cat, and about three tablespoons to kill a medium size dog.

The reason that animals ingest antifreeze is because it is sweet and tastes good to them.  If antifreeze leaks on the ground or is left in a container, following a flushing of a cooling system, pets will actively seek it out.  This is why it is extremely important to hose off any puddles on the ground that may have leaked from a vehicle, and properly dispose of  old coolant if you flush your own radiator.  Antifreeze can be easily recognized because it is a translucent bright green color.

Ethylene glycol has both immediate and long-term affects on the body.  Once consumed, it is quickly absorbed and metabolized by the body.  Peak blood concentrations occur within three hours of ingestion.  Within the first thirty minutes after drinking it, your pet will appear ataxic or intoxicated.  This intoxicated stage can last for up to six hours.  Eventually, the drunken behavior will end, and it will appear that everything is normal, again.  However, this is not the case, because the ethylene glycol enters the animal’s kidneys and liver where it is oxidized into toxic compounds that acidify the blood and destroy renal cells in the animal’s kidneys.  Once the kidneys are damaged, they are no longer able to cleanse the body of waste.  The transformation of antifreeze changes from glycoaldehyde to glyocolic acid, and oxalate.  It is the glycolic acid and oxalate that are the main causes of kidney damage and resulting uremia.  These chemicals can also cause serious damage to the central nervous system.  There is no treatment that can reverse this damage.  This type of damage can even be fatal within a few days.

Early signs of antifreeze ingestion are similar to alcohol intoxication.  It is also common for dogs and cats to vomit, as ethylene glycol is quite irritating to the stomach.  The animals will typically drink and have to urinate excessively and may seem wobbly and depressed.  After the intoxication stage wears off, the animal will likely seem much improved.  However, the next day (in cats), or two days later (in dogs), patients normally become much sicker.  They may become weak, depressed, and dehydrated.  They may also develop mouth ulcers, diarrhea, rapid breathing , and seizures.  Also. their kidneys are frequently swollen and painful.

It is only possible to save the animal when the poisoning is discovered prior to the occurrence of kidney damage.  It is much easier to identify antifreeze poisoning when the animal is in the stage where staggering and intoxicated behavior are present.  It is considerably more difficult to identify once the ethylene glycol has reached the liver, because in the early stages of this phase, the animal will appear healthy, while later in this phase, the symptoms are multisystemic and nonspecific.  These later symptoms can be confused with other diseases, like diabetes, pancreatitis, gastoenteritis, or other forms of kidney disease.  Once the ethylene glycol metabolites have attacked the kidneys, it is too late to provide a cure.

The amount of antifreeze consumed by the animal is crucial in determining the success of treatment.  Animals that have ingested a large quantity of antifreeze will not respond favorably to any type of treatment.  The purpose of treatment is to decrease the amount of absorption of the ethylene glycol in the stomach and intestines, and increase the amount of excretion through the kidneys.  Preventing the metabolism of ethylene glycol to glycolic acid and calcium oxylate, as well as correcting the acidosis of the blood are extremely important to the recovery of the animal.

The steps that your veterinarian will take are as follows:

1. Administer either hydrogen peroxide or apomorphine to get the animal to vomit any of the poison that may still be in the stomach.

2. Give the animal water in order  to thoroughly rinse out the stomach.

3. Administer activated charcoal to absorb any remaining poison.

4. Administer large amounts of intravenous saline to increase the animal’s urine production, in an effort to get the animal to excrete out as much ethylene glycol as possible.

5. Give the pet 2.5 ml of 20% (40 proof) ethanol per pound of body weight diluted in IV fluids.  This is given as a slow drip over the course of six hours for five treatments, then over the course of eight hours for four additional treatments.  At the same time, sodium bicarbonate is also given to reduce the acidity of the blood.  The amount of sodium bicarbonate to give will be determined based on the level of acidity of the animal’s urine.


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{ 26 comments… read them below or add one }

Chris April 13, 2011 at 5:52 am

This is such an important reminder with the weather warming up and more dogs and cats will be outside snooping around in the garage etc. Thanks for posting it.

Jered December 27, 2011 at 7:58 pm

The post was very informative. I am concerned about my dog, Scout, who has been acting very lethargic and strange since coming in today. He has had a erratic heartbeat, going from high and rapid to slow and irregular. He is also very thirsty but will not touch his food, which is very uncharacteristic for him..he usually eats everything that doesn’t eat him first. After reading his post I may have my parents take him to vet.

December 31, 2011 at 7:57 pm

Please let us know if Scout is alright. I hope that everything turns out okay; it is always devastating when a pet becomes ill, especially when it comes on quickly and with no obvious cause.

Tiptonk April 6, 2012 at 3:58 pm

Does antifreeze posioning cause the tongue and throat to swell?

April 9, 2012 at 5:14 pm

There are a number of chemicals and poisonous plants that can cause the tongue and throat to swell, but this is not common after antifreeze ingestion. The danger of antifreeze is related to its metabolism in the kidneys. Make sure to contact your veterinarian immediately. If you find a container that your pet has gotten into, all the better, it will assist your vet in treating your sick pet.

Karen June 19, 2012 at 12:54 pm

I was recently forced to put my loyal companion and friend to sleep. I think she may have been purposely poisoned. Is it possible that a small amount of antifreeze could have been offered to her on a milkbone and then taken a month for her organs to shut down? My girl was a 50 lb. pit bull.

June 22, 2012 at 4:22 pm

I guess that it is possible, but it doesn’t take more than 3 ounces to kill a dog of 50 pounds in a relatively short period. Regardless of the cause, I am very sorry for that you had to put your dog to sleep.

todd June 30, 2012 at 4:53 pm

i recently had my dog in the hospital for three days for antifreeze poisoning he came monday but is still not eating and is vomiting is there anything i can do or is it too late

July 5, 2012 at 10:37 am

I am not certain, as it really depends on how long before going to the vet the dog had ingested antifreeze. I think the best bet would be to contact your veterinarian and inform him or her about the dog’s continued symptoms following the hospital stay, and potentially bring your dog back in.

Best of luck to you, Todd, and your furry friend. Please let us know how everything turns out.

Donna September 5, 2012 at 6:36 am

My dog ate hot dogs that were soaking in antifreeze. We found this out immediately and rushed him to the ER vet. They induced vomitting and gave him two doses of charcoal. they were able to get all of the hot dogs out of him. They also put a liter of saline under his skin. This was done within 1 hour of ingesting. It has been 48 hours now and he seems fine. We are on pins and needles and watching him closely to see if there are any other symptons. Do you think he is out of the woods?

September 9, 2012 at 2:42 pm

This is horrible. Who intentionally poisoned your dog? I am happy that your dog is probably going to be alright, but completely appalled that someone would do something so cruel to an animal.

Cherie October 6, 2012 at 9:04 pm

I believe my darling cat ingested antifreeze based on her symptoms. Unfortunately, when I stepped inside to contact the vet, she left. I wasn’t gone above 10 minutes. She was gone without a trace. I looked for her everywhere that night and everyday since. She never wandered far from home before. She’s been gone for 7 days now. I was surprised she was able to jump over my wall as she seemed very weak in her back legs and was lethargic. She had also vomitted white foam four times in the course of about 30 minutes. I frantically tried to get help. When I finally did, she had disappeared. My question is, do you think the vet was correct in believing she had ingested antifreeze? And, how long do you think she suffered? She was fine earlier in the day. Also, do you think she’s still alive? I continue to look for her and pray for her return. I love that little gal! She’s the best!

October 14, 2012 at 1:30 pm

If she really did ingest antifreeze, she probably didn’t suffer for long. It kind of depends the amount that was consumed. Unfortunately, when animals, especially cats are very sick, they tend to go off to be alone. If your cat really did ingest antifreeze, I am fairly certain that after 7 days, she is no longer still alive. I am really sorry.

Cherie October 14, 2012 at 10:25 pm

Thank you so much for responding. My Kitty-Kat hasn’t returned. I can honestly say this has been one of THE most difficult times in my life. I’m devastated. I’ve looked for her daily. Called vets and animal control. I’ve asked people who walk and jog. I’ve looked in alleys, people yards, up and down streets. There’s been no sign of her. I’ve wished that, if she has passed on, that I would find her body so I could make her final resting place at home. Again, thank you for your response.

October 18, 2012 at 6:32 pm

As a person that has owned several cats, when they are dying, they often go hide under bushes, in a field, or other places where they will be left alone. Sadly, you may never find your beloved cat’s body. Perhaps, you could honor her memory by burying something like a toy, old collar, or the like. Never forget that regardless of where her body is, she will always be with you in spirit. I know it is hard to lose a “furry baby,” as I call them, but try to remember the good times you had with her.

Mad right now October 19, 2012 at 4:26 pm

We just unfortunately had to bury our cat today because my stupid neighbors left antifreeze in their yard and our cat ingested so much of it that when we found him yesterday, he was so drunk-looking that his eyes were rolling in the back of his head and he was completely motionless. We took him up to the emergency hospital and they told us he was very dehydrated, his temperature had dropped down to very dangerous levels and they tested him and he had a very extremely dangerous level of antifreeze in his blood. They kept him overnite pumping saline and ever clear into his system with hopes of making some changes. We picked him up this morning, took him to our vet, and he ran more blood test and it was determined that his kidneys were very damaged. We held him while they injected the fluid to put him to sleep forever. I’m hurt, my wife and kids are very distraught. It’s not fair. People need to be more cautious with this poison because it just took one of our family members off this earth.

Mary November 21, 2012 at 3:00 am

Hi, my dog vomited several times yesterday. We are at a place where there was a old car show in front of our place on a grassy area. I’m worried one of the cars may have leaked anti-freeze on the grass and perhaps my dog ate the grass. She seems fine with the exception of vomiting. She ate her dinner and has so far kept it down. Do you think I need to be concerned?

November 22, 2012 at 5:51 pm

Hello Mary,

It sounds more like your dog may have just eaten regular grass. When a dog want to vomit, they frequently grass. If your dog had ingested antifreeze, it would have appeared drunk, and then become violently ill. Simply vomiting, is not a symptom of antifreeze poisoning, especially, if the dog seemed perfectly fine a short while later. However, if you are really concerned, take your dog to the vet and have it checked out.

Margaret December 6, 2012 at 10:18 pm

Our Pekingese became ill this past Sunday, we thought she was taking a seizure, she then started passing blood through her bowels , and was gone by Monday morning. Could this have been from Anti-freeze or something else? The next evening one of our Chihuahua’s started the same thing, but my daughter has been keeping her hydrated with pedia-lite through an eye dropper. She seems to be improving. Both dogs were up to date on their parvo vaccines. So please let me know what you think.

December 8, 2012 at 3:26 pm

This sounds like something else. Bloody diarrhea is quite serious, especially if it lasts for more than a day or two. The good news is that it is probably not antifreeze poisoning (as this is nearly always fatal if left untreated). It is probably caused by some type of a bug, especially since both dogs are sick. If it lasts longer than 2 days, you really should take your dogs to the vet.

April January 7, 2013 at 10:56 am


Sounds like the new strain of Parvo. Bloody stool is a symptom and they die fast after that. The vaccine does nothing for the new strain. Im sorry for your loss.

bernadette mo August 19, 2013 at 3:40 am

My beloved friends dog “Sam” (a golden-lab mix) has been injected with anti freeze they are almost certain and been battling the blood problems. kidneys not wanting to function-then better the next day, looks so uncomfortable and sad not eating… (…hyperplasia) knot that was aspirated and it coming back this previous condition mentioned; have you ever known of this? She has a very angry business owner type law suit going on at this time………………

August 22, 2013 at 11:41 am

Hello Bernadette Mo,

I have not heard of someone injecting a dog with antifreeze, but some people are cruel. My best advice would be to take Sam to the vet. I don’t know if anything can be done to save your dog, but seeking timely medical attention is always important in antifreeze poisoning.

Michelle October 26, 2013 at 7:04 pm

My daughter’s dog had to have been given antifreeze sometime today. No idea how that could happen as there is no access to anything like that in the back yard. She came home earlier today and went out to check and he was staggering around and drooling. He’s at the vet right now. I pray he will be alright.

November 1, 2013 at 9:54 am

I am so sorry, Michelle. I hope your daughter’s dog is alright.

Courtney November 21, 2013 at 1:27 pm

Recently my dog and I stayed with a relative whose dog was given antifreeze. I am sorry to say they lost their great dane. However, i was unaware that their dog had vomitted in one of the bedroom floors. I am concerned that my dog may have eaten some of the vomit. He has been vomitting and it seems to be getting worse. Do you think i am just im being paranoid?

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