 At the same time, the fluid is no longer restrained by the gasket, so the compressed gas chamber forces the injection fluid chamber to empty into the target (see diagrams from Veterinary Technician).It has also been suggested that the momentum of a steel ball at the rear of the dart could push the syringe plunger in some designs.In each of these methods, intramuscularly injects carries a dose of barbiturate or other sedative drugs into the animal.