What Medication Is Used to Put a Dog to Sleep for Surgery?

Even when a pet is going in for minor surgery, it’s unnerving for the caring owner. Good veterinarians are aware of this. Before any surgery, they listen to the pet's heart for sounds of a murmur and make sure his lungs are clear. Often pre-surgical lab work is run, and since anesthetic agents are dosed by weight, an accurate weight always is taken and logged.

Telazol (tiletamine hydrochloride 50/mL, zolazepam hydrochloride 50 mg/mL) is a veterinary medicine that is similar to ketamine in effectiveness and structural compound. It's used commonly in small animal practices as an anesthetic agent, and typically is administered intravenously. However, if a dog or cat is fractious, it can be given intramuscularly for restraint purposes. When given intravenously, anesthetic effects are almost immediate. Telazol is not used typically when an animal has severe pancreatic or renal problems, or cardiac dysfunction.

Ketamine was developed initially for use in humans. It now is used in all species of primates, as well as birds and reptiles. Anesthetically, when ketamine is used alone it has limitations. However, when combined with other depressants of the central nervous system, such as diazepam (Valium), it provides safe and effective sedation. It is acceptable for use in sight hounds, and for animals with well managed heart disease. Doses are mixed together in the same syringe and given intravenously. It is not recommended to be given in the muscle, because diazepam not only stings, but is not well absorbed.

Propofol is given intravenously and can be used in animals with preexisting diseases, or when a rapid recovery is important. Propofol causes a substantial drop in respiration, and is not recommended for long surgeries. For short noninvasive procedures, such as an exam or radiographs, telazol or Valium and ketamine can be used without additional anesthesia. However, propofol must be administered constantly through an IV for the pet to stay asleep. Once propofol is no longer given, the animal awakens rapidly.

When an extensive surgery is required, sedatives, such as telazol, propofol or ketamine, are used as a preinduction to anesthesia. Once sedated, an intratracheal tube is placed for breathing, and a mixture of inhalant gas and oxygen is administered. Isoflurane is a halogenated ether, and is used commonly in veterinary medicine. Oxygen is delivered at an average flow rate of 1 liter per minute, depending on the size of the animal, and isoflurane is delivered at approximately 3%. Isoflurane has little to no adverse side effects on the pet.