A recent 2022 study highlighted the euthanasia challenges veterinarians encounter outside of the companion animal space (think zoos, wildlife management, research).  I found it particularly interesting reading about the types of species being helped and what the veterinarians deemed difficult, especially in comparison to the situations private practice veterinarians face. Euthanasia is a common veterinary procedure in every region of the world, and the reality is while we want everything to go perfect, it might not.  It’s how we prepare and manage the procedure real time that makes the difference between a good death and a rough one.  

Even though the reported number of complicated euthanasia in non-domestic species was small (n=41), the takeaways were very telling. We all have our challenges. Species included bears to baboons to bald eagles, and yes even whales. The euthanasia complications were as follows, in order of frequency reported by veterinarians.

1. Took an excessive amount of euthanasia solution
2. Heart would not stop
3. Prolonged tremoring or agonal breaths
4. A secondary method was required
5. Animal awoke at a later time
6. Difficulty injecting a vein
7. Other – regurgitation or aspiration, adverse public response, multiple gunshots needed

The most common complications occurred in mammals, which surprised the authors who hypothesized that most issues would happen with other taxa. In veterinary school, while euthanasia training is minimal, mammal euthanasia is taught the most.  Perhaps more mammal issues were reported because more mammals are euthanized on average. Pentobarbital injections were the most common euthanasia method, which is true in companion animal euthanasia too.

What private practice veterinarians can learn from this study is that working with non-domestic species takes additional training, and this holds true for companion exotic species (e.g., reptiles, birds, amphibians, fish, and larger ones like tigers, wallabies, and monkees). And that patience with the process is paramount.  Rushing is always counterproductive.

The study gives the following recommendations:

1. Higher pentobarbital dosing may be required – always have extra on hand.
2. A secondary method may be needed – be prepared to conduct a second injection of a non-pentobarbital agent or a physical method. E.g., pithing brains in reptiles.
3. Auscultating the heart can be hard – think about using Doppler, ECG, cardiac ultrasound, and end-tidal carbon dioxide to confirm death.
4. Intravenous access might be tough – vets need to be familiar with all injection locations like intracardiac, intrarenal, and intrahepatic for pentobarbital administration.

While euthanasia is defined as a rapid, pain-free death, a slower death in an unconscious patient is acceptable as long as witnesses understand what’s occurring and why. The goal is to reduce suffering through experiences like pain, breathlessness, and seizures. While many veterinarians reported seeing active signs of death like agonal breathing and muscle tremors, they do not equal a dysthanasia for the patient.  They can be hard for observers to see and hence why some negative reporting occurred. The potential for active signs of death and a prolonged time to death in non-domestic species increases the need to inform witnesses about what is normal, what may happen, and the necessity for patience and trust for the duration of the procedure. These challenges are not unique to non-domestic species. We have similar challenges with dogs, cats, horses, and other family pets.

I learned a lot from this study’s publication and it’s why I spend as much time as I do reading about other veterinary industries, including animal research, food production, and wildlife management. There is much to understand about all aspects of euthanasia.  The more we know, hopefully the better our skills.  While the Companion Animal Euthanasia Training Academy (CAETA) does not teach a lot about non-domestic species, we thank the study’s authors for bringing the information to us and encouraging more research in this area.

Reference
Hepps Keeney, Caitlin, and Tara M. Harrison. “Euthanasia Complications in Non-Domestic Species.” Journal of zoological and botanical gardens 3.4 (2022): 616–623. Web.