Question

To capture wild elephant the commonly used anesthetic is:

• A. Xylazine
• B. Etorphine
• C. Medazolam
• D. Morphin

Hint:

In wild animal medicine, remember "M99" as the synonym for Etorphine.
It is the drug of choice for darting heavy megaherbivores (elephants and rhinoceroses) due to its extremely low volume requirement and rapid induction.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Chemical immobilization of large wild mammals, such as elephants, requires highly potent anesthetic agents that can be delivered in small volumes via remote darting systems.
The drug must have a rapid onset of action to prevent the animal from traveling long distances before recumbency occurs, and it must be reversible.

Step 2: Detailed Explanation:
Let us analyze the suitability of the listed agents:
- Xylazine: An alpha-2 adrenergic agonist used primarily for sedation and mild analgesia in domestic animals.
While it is used in wildlife, the volume required for large megaherbivores like wild elephants is too high, and the induction time is too slow.
- Etorphine (M99): A semi-synthetic opioid with a potency approximately 1,000 to 8,000 times greater than morphine.
Due to its extreme potency, a very small volume (a few milligrams) is sufficient to rapidly immobilize a wild elephant.
Its effects can be immediately reversed using specific antagonists like diprenorphine or naltrexone.
- Midazolam: A benzodiazepine tranquilizer used primarily as an adjunct for muscle relaxation, not as a primary immobilizing agent.
- Morphine: A standard opioid analgesic that lacks the necessary potency for immobilizing massive wild animals safely in field conditions.

Step 3: Final Answer:
Thus, the most commonly used anesthetic agent for capturing wild elephants is Etorphine.