I was hoping there are some Vets or animal lovers out there. I am curious to several things about animal anesthesiology (testing accuracy of historical fiction) First, are these drugs one and same, only the dosage varies? Is this correct, or a mistake? Also, whether right or wrong, what is/are the common names of both drugs? Is there a common brand name? Or, are these things known best by a chemcial name, like ether once was…the only example I know!
Please enlighten me as the drugs of choice for an operation as well as one must be, sadly, put to sleep. (And, are any of these drugs also used in human ORs???) Please provide info for both dogs and cats, if it should matter.
I’m not a vet, but I know a bit about this – perhaps a vet will be able to provide a fuller answer. The drugs most often used for euthanasia are sodium phenobarbital and sodium thiopental (sodium Pentothal). Sodium thiopental is the first of three drugs used in execution by lethal injection.
Any list of veterinary anesthetics I’ve seen has been in a textbook, so it’s been a fairly complete list. A vet would be able to say which were actually used in modern veterinary surgery. I would think that barbiturates such as sodium phenobarbital (which is too long-acting to be practical in surgery) and sodium thiopental (which is very short-acting, but can be used as an anesthetic if it is administered continually) are not commonly used now. They are very dangerous in overdose, and a vet might want to minimize their use because they are controlled substances.
Some of the major anesthetics used in humans are used in animals as well, such as the inhalation anesthetics halothane and isoflurane. These are not good choices for all animal species, however. In some species (cats, rats), ketamine is a useful anesthetic; it is safe and easy to use. It is not often used in humans because of its psychological effects. Most of the lists also include very old anesthetics (ether, carbon tetrachloride) that are probably no longer used.
Here is a thorough discussion of veterinary anesthetics. To answer your questions more directly: It’s possible that the drug most commonly used in euthanasia, sodium phenobarbital, can be used in anesthesia at a lower dose, but it’s unlikely. The drugs used for anesthesia vary widely between species and depend on the needs of the operation being performed. Some of these drugs are used in humans, others are not.
When I worked in a vet clinic (2000 - 2002), we used a valium/ketamine injection to initially sedate the animal and maintained anesthesia with an isoflourane/oxygen mix administered via tracheal tube. We did purchase another inhaled anesthetic near the end of my tenure specifically designed for older dogs (don’t remember what it was).
As for euthanasia, the drug combo we used was pentobarbital sodium and phenytoin sodium. It was bright pink, and called “Euthasol.” Oddly enough, the drug is used as an anti-convulsant in humans. (Another tech remarked that her old clinic had used blue Fatal-Plus!)
Our regular vet used a somewhat complex method for euthanasia. She had three syringes: sterile saline, val/ket, and Euthasol. She would use a butterfly needle with a bit of tubing attached (like the kind used for a regular IV line) to start, and make sure she was in the vein with the saline. Then, she’d give them val/ket for sedation (and you’d get a big sigh from 'em). A little more saline, then the pink stuff.
At my old clinic, we induced with sodium thiopentothal, then intubated and maintained with isoflurane. For especially fractious cats, we popped 'em into a little box and hooked it up to the isoflurane until they fell asleep and we could intubate. Most of the vets at my current job prefer to induce with propofol (commonly used in humans and referred to as “milk of amnesia”), but our new ER doc likes the ket/val combo.
For very debilitated animals, we have the option of maintaining them with sevoflurane gas, which is apparently just the most wonderful gas anesthetic ever. It’s something like seven times as expensive as iso, though, so we only use it for animals that we don’t think will do well on the iso.
There’s a huge array of things you can use to knock an animal out–large animal vets often use xylazine (Rompum) or a xylazine-containing cocktail, we sometimes just give an IM injection of Domitor, and you can even knock 'em out with a combination of acepromazine and narcotic pain meds (I wouldn’t suggest that, though, it tends to lower their blood pressure quite a bit).
My old clinic used Euthasol, and we have it in stock sometimes, but we generally use Fatal Plus. AFAIK, there’s about as much difference between them as there is between Anacin and Bayer. Same drug, different manufacturer.
Euthanasia solution is just a massive overdose of barbituates, and many anesthetics contain barbituates. So they’re often the same class of drugs, and sometimes very similar drugs, but they’re usually not the exact same drug in a different dosage.
(Another tech remarked that her old clinic had used blue Fatal-Plus!)