Antifreeze is extremely dangerous and deadly to dogs. It contains ethylene glycol which can also be found in RV antifreeze that is used to keep water lines from freezing in homes and RV's during the winter, as well as in brake fluid.
Ethylene glycol is deadly to dogs and it doesn't take much to do it's damage. Just 2 tablespoons of antifreeze can kill a small dog and as little as 3 ounces will kill a medium sized dog.
The sweet smell of antifreeze is attractive to dogs and they will drink or lick up more than enough to do harm before the nasty aftertaste kicks in and they realize it doesn't taste so good after all. At that point It's most likely too late unless you get immediate medical treatment and I mean immediate!
Ethylene glycol destroys the kidneys and effects the brain and liver and if untreated your dog will die in short order. So make sure there is no access to these products in your home or garage or any home or garage you may visit with your dog.
If you have a car that is leaking antifreeze or brake fluid, make sure you clean it up and get your vehicle fixed immediately. Even a very small amount is enough to cause Kidney failure within just a few days.
If you live far from your vet and you know that your dog has ingested ethylene glycol within the last two hours there is an emergency treatment you can try to induce vomiting but PLEASE, before trying this call your vet first. If for some reason you can't get hold of your vet, call the Animal Poison Control Center 800-213-6680. The treatment is a solution of hydrogen peroxide, one teaspoon per 5 lbs. of body weight, not to exceed 3 teaspoons given at once. You can give three doses spacing them ten minutes apart. If your dog fails to vomit stop giving the hydrogen peroxide. If you do try this you still need to get to the vet as soon as you can whether your dog has vomited or not!
Don't try this if your dog is unconscious or having a hard time breathing or otherwise in serious distress. CALL YOUR VET FIRST as some toxins can do even more damage on the way up!
The absolute best course of action is to get immediate medical attention.
If you don't know your dog has gotten into antifreeze, these symptoms may alert you that they need help ASAP;
Wobbly movement, uncoordinated drunken behavior, nausea, vomiting, excessive urination, diarrhea, weakness or fainting, delirium, seizures or convulsions, a rapid heart beat, coma, depression or even euphoria. Smell their breath and see if you get a whiff of antifreeze.
A rather large tube is shoved down the throat into the stomach and activated charcoal is forced down the tube. The charcoal is meant to absorb the antifreeze molecules so your dog's body doesn't. So you can see the importance of quick action on your part. If it has been too long since it has been ingested, it's probably too late. Your vet will can also administer 4-methylpyrazole which is an alcohol dehydrogenase inhibitor but again, it's only effective if given shortly after ingestion.
The bottom line is ethylene glycol is deadly so the best course of action is to make sure your dog can never get near the stuff. Antifreeze poisoning is one of the most common forms of poisoning in dogs and other small animals.
As always, prevention is the best medicine!