The drugs used for animal immobilization may be dispensed in one of two ways. The choice of drugs and prevailing circumstances will be the deciding factors.
The first method consists of loading the darts after the target animal has been located and observed. The animal’s weight is estimated and its physical and mental condition noted. Other factors which may influence the choice of drug dosage are age, sex, stress level, and aggressiveness. On this basis, the dosage is calculated and loaded in a dart of suitable volume capacity. This is the safest method and provides the best control of dosage, induction time and level of immobilization. The disadvantages of this method are the time required to calculate the dosage and load the darts, and the problems of dispensing drugs and filling darts under difficult field conditions.
The second method consists of the use of darts loaded before the animal is located or observed. This method can only be used for the central nervous system drugs because their relatively wide safety margin makes accurate weight estimation less critical for dosage calculation. Darts can be preloaded by a veterinarian for a certain species and size of animal and given to the worker as may be required. (Note: Preloading darts is not recommended. If you choose to preload, the darts should be used within 24 hours.)