If you take a moment to reflect on the most dangerous substances we inject into the body, you may come up with the same answer as I did. Chemotherapy. These drugs by nature destroy cells, and cause considerable damage to tissue in areas of accidental contact such as extravasation outside of the venous system. They are highly caustic and can lead to severe pain when they escape the vein. Oncology services always place indwelling intravenous (IV) catheters to administer those that require venous dosing. Euthanasia solution while also dangerous is not so different, and pain during death does not equal a good death. Indwelling catheters provide a guarantee and during a procedure of no do-overs, I’ll take the guarantee.
For intravenous euthanasia, there are three possible injection paths veterinary professionals can take. The first is what’s referred to as direct venipuncture, meaning a needle attached to a syringe is inserted into the vein and solution injected. The second is the use of a butterfly catheter which is a needle with a small extension set attached to a syringe. The third option is the indwelling catheter, a small plastic tube seated into the vein and anchored in position with tape to prevent it from coming out.
The American Veterinary Medical Association, the American Animal Hospital Association, and the Companion Animal Euthanasia Training Academy have all taken the same position on use of indwelling IV catheters for euthanasia. If euthanasia solution is to be administered into a vein, an indwelling catheter is the safest approach. Pentobarbital, the most common euthanasia solution is highly alkaline (high pH) and other euthanasia solutions require rapid administration wherein should the needle come out of the vein, the patient may suffer. Intravenous catheter placement reduces the risk of solution leaking out, plus should reduce the risk of needles lacerating the vein. While these 3 veterinary groups and others also advocate for pre-euthanasia sedation or anesthesia which reduces the need for patient restraint during the euthanasia injection, a sleeping pet does not ensure a needle won’t inadvertently penetrate through the vein wall. A sleeping pet may be unaware of the solution leaking out, but to a grieving family expecting an uncomplicated death, it may lead to unnecessary worry and stress.
Another benefit to the placement of indwelling catheters is the ability of veterinary professionals to locate the vein, place the catheter, then provide the pet owners/caregivers time to be with their pet in privacy. Blood pressures may continue to drop due to poor health or use of sedatives/anesthetics, but the vein remains fully accessible. When the owners are mentally ready to proceed, the solution will be administered smoothly. Ideally the owners never have to wait for the vein to be found seconds before they expect their pet to die.
My passion in euthanasia work it to educate on how to perform the smoothest procedure possible, with the least amount of risk. Those who tell me they prefer to use butterfly catheters because they aren’t good at placing IV catheters have the opportunity to learn. In my opinion, it’s a lot less complicated than many think. When we know better, we can do better. I wasn’t always good at IV catheter placement. It took a few tries in the beginning, but I got there and never looked back. And if accessing veins in the first place is stressful, there are always intraorgan techniques.
MacDonald V. Chemotherapy: managing side effects and safe handling. Can Vet J. 2009;50(6):665-668. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2684058/
AVMA Guidelines for the Euthanasia of Animals 2020. https://www.avma.org/resources-tools/avma-policies/avma-guidelines-euthanasia-animals
2016 AAHA/IAAHPC End-of-Life Care Guidelines. https://www.aaha.org/aaha-guidelines/end-of-life-care/end-of-life-care-guidelines/
AAHA End-of-life Accreditation program. https://www.aaha.org/accreditation–membership/specialty-accreditation/end-of-life-care-accreditation/