Antifreeze contains ethylene glycol, a substance that is toxic to pets. Antifreeze tastes very sweet to pets and even a small amount can prove fatal. Signs of toxicity include vomiting, lethargy and a sweet odor to the pet's breath. Use caution when adding antifreeze to your car and clean any spills immediately. If you suspect your cat or dog may have come in contact with antifreeze, call us immediately.