The nature of wild and exotic animals nearly always necessitates the use of chemical immobilization for their handling and manipulation. Anesthetizing wild and exotic animals is typically done for the purposes of research, wildlife management, animal control or to render individual medical treatment to animals.
Anesthesia of wildlife species is challenging and often requires that veterinarians and wildlife managers adjust the principles of anesthesia to the physiological parameters of various wildlife species under difficult field conditions, since specific anatomical and physiological details of target animals are not always available.1 For many years, morbidity and mortality in animals undergoing field anesthetic procedures was not uncommon. More recently however, veterinarians working with custom compounding pharmacies have been instrumental in formulating drug combinations that are safer and minimize stress in animals.
In the United States, all of the drugs used for the chemical immobilization of animals (wild and domestic) are regulated under federal law by the U.S. Department of Agriculture (USDA) and tracked by the U.S. Drug Enforcement Agency (DEA). As such, a licensed veterinarian must serve as the system administrator as regards the procurement and disposition of all of the chemical immobilizing agents used by the wide range of organization types engaging in the chemical immobilization of animals (e.g., veterinary clinics, universities, research institutions, government agencies, park services, etc.).
The strategies of approach in delivering chemical immobilizing agents (drugs) to wild/exotic animals differs, and is usually predicated upon the circumstances and venue.2 In general, these consist of:
Manual injection using a hand-held syringe might be used in a zoo setting with smaller animals, or with free-ranging animals that have been captured and restrained using nets. Drugs can be also administered to larger and more unpredictable animals that have been trapped or approached at shorter distances via pole syringes (“jab sticks”). These provide a means of injecting animals in situations where hand injection is unsafe, and/or adequate restraint facilities are unavailable. Pole syringes consist of a metal, plastic or nylon barrel attached to a flexible plunger. These are sold in several different lengths and essentially represent a syringe on a stick.
Remote delivery systems have become popular in recent years and are widely used in the chemical immobilization of free-ranging animals. With these systems, a premixed drug or drug combination is drawn into the dart, which is placed into a customized rifle or pistol. Dart guns typically utilize pressured gas to deliver the dart to an animal. These may be fired from the ground, a ground vehicle or a helicopter. Blow guns can also be used for the purposes of remote delivery, but their applications are limited, since these rely on close proximity and are breath-powered.
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1Arnemo, J., Kreeger, T. (2018). Handbook of Wildlife Chemical Immobilization 5th Ed. Sunquest Publishing, 2007, 432 pages.