If your pet has drank antifreeze, than it will look as is he/she is walking around drunk and attempting to drink unusual amounts of water. He will not be able to walk in a straight line and barely keep his posture, which is the biggest single that something is seriously wrong with the animal. You have to realize that these symptoms may be a result from many things, but in this case, it is extremely important that you seek the proper treatment because antifreeze will prove fatal if not taken care of on time.
Go to a Vet
This is the most important part because doing so can mean the difference between your pet living or dying and you would obviously would not want the latter happening in any situation. Even a tiny taste of the chemical can mean very bad things, which is why rushing the pet for medical treatment is crucial. The worst part is that the early symptoms that were discussed above may begin to wear off just a few hours after they occurred, but trust experience, there are worst things to come.
Get Proper Medical Treatment
If the antifreeze affects your pet's kidneys and liver in a negative way, you have to come to reality with the situation that your pet may not be on this Earth for much longer if the vet is unable to do anything else but suggest a kidney transplant.
Keep such poison away from pets reach and sealed in all cases and situation as it is extremely harmful and dangerous for their health and basically anyone and anything that is vulnerable to attempt to drink it like young children as well.