The present invention provides an injector for an animal, which comprises: a length adjusting part adjusting the length through connection between a first adjusting part and a second adjusting part having different diameters a needle part connected to the front of the length adjusting part and a drug injecting part which is coupled to a drug container and located between the length adjusting part and the injection needle part and into which the drug is injected through the injection needle part through the pressurization of the length adjusting part. Embodiments provide the injector for the animal which can adjust the length and can ensure safety by projecting an injection needle only at the time of injection.본 발명은 서로 다른 관경을 가진 제1 조절부와 제2 조절부의 연결을 통해 길이를 조절 할 수 있는 길이조절부, 상기 길이조절부의 전방에 연결되는 주사바늘부 및 약품통이 결합되며, 상기 길이조절부와 상기 주사바늘부 사이에 위치하고, 상기 길이조절부의 가압을 통해 상기 주사바늘부로 약품이 투입되는 약품투입부를 포함하는 동물용 주사기를 제공한다.
