Beer is not safe for dogs as it causes the same damage to the dog’s liver, kidneys and brain as in humans, but due to a dog’s smaller size the alcohol damage occurs more quickly. Not only is beer potentially damaging to dogs, it can even be deadly.
According to the Pet Poison Helpline alcohol is especially poisonous to small dogs and cats, and it has the possibility of leading to their death if they drink too much. Alcohol in any form is dangerous. This includes beer and other alcoholic beverages cooked into things such as cakes soaked in rum or different types of yeast dough.
Dehydration is a serious risk with alcohol. It is a risk in humans as well, and the primary cause of hangovers, but the risk is even greater in dogs due to their smaller body size and the fact that dogs need a lot of water to stay healthy. If they drink beer instead of water they will not get the hydration they need. This sometimes leads to death.
Other dangers drinking beer poses to dogs include depression of the nervous system, cardiac arrest and low blood sugar, which can cause seizures and brain damage.