A syringe (2) for injecting a substance to be administered into or through the skin of an animal or human comprising a reservoir (4) adapted to contain a substance to be administered to the animal or human, an introduction means (8) for introducing the substance to be administered into the animal or human, a dispensing means (12) suitable for dispensing a dose of the content of the reservoir from the reservoir into the animal or human via the introduction means, and a means (16) for actuating the dispensing means, characterised in that the syringe further comprises one or more of a means limiting the use of the syringe to one or other of the hands of the user, a means for monitoring the quantity of substance in the reservoir, a means to limit which substance may be introduced into the reservoir, the reservoir is reversibly removable from the syringe, or the syringe further comprises a means for marking the position where the introduction means has entered the skin.
