Immediately induce vomiting and then take the cat to a veterinarian. That, in a nutshell, is how you administer urgent treatment to a cat poisoned by antifreeze. I have more or less quoted respected veterinarians.

Hydrogen Peroxide

If treatment is delayed, administer activated charcoal to prevent further absorption of ethylene glycol.

Your vet will then place the cat on IV fluids and give ethanol treatment to prevent the metabolisation of ethylene glycol.

Then there will be intensive care and some vets offer dialysis as part of the treatment. It is possible to save a cat who who has been poisoned like this.

A visitor to PoC, Ashlee Furr, who is involved in cat rescue work asked you can urgently treat a cat who has been poisoned by antifreeze. We know that ethanol treatment is part of the overall veterinary treatment for cat poisoned by antifreeze containing ethylene glycol. What can a cat rescuer do? Well, they can as stated above induce vomiting.

This is how you do it. I have never done it.

You give the cat hydrogen peroxide (H₂O₂). It is a 3 percent solution (the concentration level is very important). I’ll selectively quote:

“Give 1 teaspoon (5ml) hydrogen peroxide per 10 pounds (4.53kg) of body weight, with a limit of 3 teaspoons. If the cat doesn’t vomit after the first dose, you may repeat every 10 minutes, up to three times, until the cat vomits. If possible get your cat to walk around and shake him gently in your arms after giving the H₂O₂. This helps to stimulate vomiting.”

When the poison has been removed from the stomach give him/her activated charcoal. This binds any remaining poison. Compressed activated charcoal is recommended. It comes in tablet form.

The dosage is one tablet per 10 pounds of cat body weight (one tablet for the average cat). Some activated charcoal products come in powder form which can be mixed with water and added to food. However the best way to administer is by a stomach tube which is essentially veterinarian’s work.

If you don’t have activated charcoal you can coat the intestines with milk and egg whites. It should be a quarter cup egg whites and a quarter cup milk — give 10ml by mouth by dripping it into the cat’s cheek pouch with a syringe or add it to food.

That is about it as far as non-veterinarian treatment is concerned. It would seem sensible for a dedicated cat rescuer to keep the required products mentioned above to hand at all times. Antifreeze poisoning is not that unusual especially of stray and wandering outside cats.

There are many pages on this topic.