Abstract: A pellet implanter for the subcutaneous implantation of one or more spherical or cylindrical pellets of a total size of up to about 1/8 inch by 1 inch (3 mm .times. 25 mm) through a hypodermic needle uses a transparent compact flat cartridge having parallel feed chambers permitting visual observation of the feed and 360.degree. rotation of the cartridge holder with respect to the pistol grip and plunger assembly. A collet holds a replaceable injection needle which permits injection of therapeutic agents in repository form beneath the skin of animals for therapeutic and/or growth control purposes.