In dogs, it can be deadly to the kidneys. It's part of what makes a dog a dog and a person a person, differences that occur in the tiniest, most internal workings of the insides of cells. Differences in enzymes and chemical processes that are subtle, but crucial. Treatments might be similar for a dog and a person for similar conditions. A common example is treatment for seizures, or epilepsy.
Phenobarbital taken orally is the most common treatment.
Just last week concerns were raised about possible damage to people's livers. Acetaminophen is deadly in cats, not only in their livers, but because of damage that occurs in the hemoglobin of red blood cells that destroys their oxygen-carrying capacity. They can literally suffocate because of administration of the drug. It should never be given to dogs or cats. Notice that we haven't said anything about dosages.