The Best Way to Euthanize Awake Pets with IV Pentobarbital (if you must)

CAETA is known for its advocacy of pre-euthanasia sleep for companion pets. It is part of our 14 essential components of companion animal euthanasia and the backbone of our ability to teach varied euthanasia techniques, including intraorgan injections. We preach the use of sedatives and anesthetics so regularly that sometimes I forget there are people and places that can’t, or won’t, induce sleep before death. Whatever the reason for keeping the patient awake during intravenous (IV) pentobarbital administration, there are ways to still improve the experience for the pet patient, owner, and animal care team when pre-sleep cannot be provided. 

While many euthanasia solutions (e.g., potassium chloride, magnesium sulfate, lidocaine) require pre-euthanasia unconsciousness/anesthesia, pentobarbital does not. It is an anesthetic drug that induces unconsciousness before the heart stops. Pentobarbital IV administration is considered a pain-free experience for the patient because it is so fast-acting. First, the brain stops functioning, then the breathing stops, and then the heart. It’s a reliable cascade of events that will lead to death every time, assuming a proper dose was given directly into the vein. Pentobarbital drugs are labeled for IV administration, and nowhere on the label does it say that pre-euthanasia sleep is required. Patients are considered awake if they have no pre-euthanasia sedatives or anesthetics in their system or when mild sedatives have been given but the patient is still able to hold their head up and look around the room. 

In order to keep IV pentobarbital euthanasia smooth and pain-free, however, a few key approaches are necessary. 

1. Pentobarbital has to be injected quickly, around 1ml per second or faster. This is done to avoid a patient’s voluntary and involuntary response to the drug as it reaches the brain. Because pentobarbital is an anesthetic drug, the patient will go through all 5 stages of anesthesia and may show signs of dysphoria, such as paddling, large body stretches, and vocalizing. This can be unpleasant to see. To the owner, it can look like suffering even though the patient may be unaware of their movements. The faster pentobarbital reaches the brain (where it elicits its primary effects), the quieter death will be.
2. Inject pentobarbital through an indwelling IV catheter. A catheter is like a guarantee that when the drug is injected, it all goes into the vein, with little to no risk of it leaking into nearby tissues. Pentobarbital is very alkaline and burns the patient if it gets outside the vein. No one wants to see that. Once the IV catheter is in place, pentobarbital can be rapidly administered to effect. Death is likely in under 1 minute; however, the heart can keep beating for up to 2 minutes or longer, depending on the species. Injecting directly into the vein without a catheter is riskier; the awake patient may move and dislodge the needle, or the euthanasia practitioner may slip and push the needle through the vein. Both of these scenarios lead to pain and patient distress. And remember that if you want to inject fast, use a large-bore catheter to allow large volumes of drug to pass through quickly.
3. Pet owners will need to be prepared for what awake pentobarbital euthanasia looks like. Years ago, I had an owner request a natural death for her dog rather than euthanasia because when her previous dog died, she saw the “light” leave the eyes as he fell to the ground, and it’s haunted her ever since. It can be jarring to see a beloved pet die so quickly. What will owners see? The patient may fall abruptly to the ground or table. They may paddle their legs, look panicked, vocalize, and take deep agonal breaths. Urination and defecation can happen immediately, too. Pet owners can be prepared for such things by veterinary teams using calm, simple language such as…
   1. “We will see her body quickly relax.”
   2. “Her body may move involuntarily as the drugs take effect.”
   3. “It’s normal for the body to move during death, including deep reflexive breathing.” 
   4. “She knows that you are right here with her, loving and caring for her as you always have.”

You may have a veterinary service that gives the anesthetic drug propofol before IV pentobarbital. If you do, you are giving pentobarbital to an unconscious patient. They are not awake and fast pentobarbital administration is less important. The same is true if your patient has been given intramuscular or subcutaneous injections of strong sedatives and anesthetics. You may give pentobarbital much slower if you wish.

Here are a few more tips to ease the IV pentobarbital administration experience in awake patients:

1. Calm the patient. Have them resting quietly before attempting to inject. Ask all witnesses, including the family, to create a calm and relaxed setting.
2. Choose a reliable vein that is easy to access and inject. Clip fur to increase your success on the first injection.
3. If placing an indwelling IV catheter, tape it securely in place so if the patient moves, the catheter remains in the vein.
4. Consider giving at least a light sedative to help reduce patient movement during the pentobarbital injection.
5. Prepare potty pads or towels to place under the patient for urination and defecation. These can be tucked underneath at the moment of death if not before.

So why CAETA’s big push for pre-euthanasia sleep? By giving heavy sedation or anesthesia to pet patients before IV pentobarbital injections, the risk of a painful injection and stress goes way down. The patient is sleeping and the body is still, making IV euthanasia injections much easier to carry out. They are more likely to have a quiet death with reduced active signs of death, too. And these days, pre-euthanasia sleep has become the gold standard by groups like the AVMA, AAHA, CAETA, and Fear Free. If you cannot provide it, hopefully the tips given here will lead to smoother passings for your pet patients.

Want to learn more about peaceful euthanasia best practices? The Companion Animal Euthanasia Training Academy (CAETA) has what your team needs.