The Single-Motion Vaccinator and Marker is a bottle-mounted veterinary syringe that simultaneously injects and marks the animal, requiring only one hand to operate. The bottle of medication or vaccine is directly connected to the syringe, with a can of paint mounted to the top. A squeeze of the handle activates the paint can, marking each animal as it is serviced, which helps to verify and track such critical treatments as administering antibiotics. The device is available in 0.5, 2, and 5 cc sizes, and the 2.2 ounce paint cans come in multiple colors.