Some classes of human sedatives, including benzodiazepines, are also used to treat dogs, states the Merck Veterinary Manual. However, they present with varying levels of risk and should not be administered unsupervised, as they can be very toxic in doses that would be harmless to humans.
Certain human medications, such as diazepam, morphine and ketamine, are also used in dogs to treat anxiety or to induce a lethargic state, explains the Merck Veterinary Manual.
Perhaps the most notorious of these is Ketamine, an animal tranquilizer that was originally invented for human use, explains Ketamine.com. While it still sees use in both the human medical and veterinary fields, it is infamous as a street drug.
Diazepam, also known as Valium, is the most commonly used human benzodiazepine for dogs. It is used to treat seizures and anxiety, states the Merck Veterinary Manual. Canigivemydog.com adds that the drug is usually only prescribed in the short term to dogs, as it is highly addictive.
Opoids such as morphine are severely toxic to dogs and cats, but they are also used for pain treatment, notes Pet Poison Hotline.