How do you give a rat a subcutaneous injection? - briefly
Secure the rat in a restrainer, lift a dorsal skin fold, and insert a 25–30 G needle at a 45° angle into the subcutaneous space, then depress the plunger to deliver the dose. Release the skin and observe the animal for any adverse reaction.
How do you give a rat a subcutaneous injection? - in detail
Administering a subcutaneous injection to a laboratory rat requires preparation, proper restraint, precise needle placement, and post‑procedure monitoring.
Materials
- Sterile 1‑ml syringe with a 25‑27‑gauge needle, length 5‑7 mm
- Appropriate drug or solution, prepared under aseptic conditions
- Alcohol swabs or sterile saline for site cleaning
- Disposable gloves, lab coat, and eye protection
- Restraint device (e.g., Plexiglas tube, tail‑hold board) or manual technique
Preparation
- Verify the correct dose and concentration; calculate volume based on the animal’s weight.
- Draw the exact volume into the syringe, expel air bubbles, and confirm the needle is securely attached.
- Label the syringe with drug name, concentration, and dosage.
Animal handling
- Place the rat on a clean surface, allowing it to calm for a few seconds.
- Apply gentle but firm restraint: hold the animal’s torso with one hand while the other hand secures the tail or uses a restraining tube.
- Ensure the rat’s eyes are protected and breathing remains unimpeded.
Injection site selection
- Choose the loose skin over the dorsal thoracic region or the lateral flank, avoiding the spine and abdominal viscera.
- Pinch a small fold of skin to create a tent, which lifts the subcutaneous tissue away from underlying muscle.
Technique
- Disinfect the selected area with an alcohol swab; allow it to dry.
- Insert the needle at a shallow angle (10‑30°) into the tented skin, advancing until the hub rests against the skin surface.
- Depress the plunger slowly to deliver the entire volume; avoid rapid injection that can cause tissue damage.
- Withdraw the needle at the same angle, release the skin fold, and apply gentle pressure with a sterile gauze to minimize bleeding.
Post‑injection care
- Observe the rat for at least 10 minutes for signs of distress, excessive bleeding, or adverse reactions.
- Record the injection details in the animal’s log, including date, time, dose, and any observations.
- Dispose of used syringes and needles in a designated sharps container; decontaminate work surfaces.
Following these steps ensures accurate delivery of subcutaneous compounds while maintaining animal welfare and experimental integrity.