Source: Kay Stewart, RVT, RLATG, CMAR; Valerie A. Schroeder, RVT, RLATG. University of Notre Dame, IN

As many research protocols require that a substance be injected into an animal, the route of delivery and the amount of the substance must be accurately determined. There are several routes of administration available in the mouse and rat. Which route to use is determined by several factors of the substance to be injected: the pH of the solution, the volume required for the desired dosage, and the viscosity of the solution. Severe tissue damage can occur if a substance is administered incorrectly. This video looks at the various restraint methods and technical details for the most commonly used injection routes.

1. Subcutaneous injection

1. Manually restrain the mouse via the one-handed restraint hold. Once grasped, allow the mouse to rest on a table or other secure surface. Be sure to avoid putting pressure on the body of the mouse.
2. Rest the heel of the hand on the table to avoid undue weight on the mouse that can compromise respirations. Mice can also be restrained in a commercial device. For rats, it is best to use a commercial restraint device.
3. Grasp the skin, and pull upward to create a tent of

Substance administration is a common component of experimental protocols that utilize animals. When choosing a route of delivery, many factors must be deliberated, including the technical proficiency of those individuals responsible for dosing the animals, the size of the animal, the viscosity of the fluid, and the amount to be administered. Careful consideration of these factors will enhance the wellbeing of the animal and the overall outcome of the experiment.