How should a rat be given a prednisolone injection?

How should a rat be given a prednisolone injection? - briefly

Administer prednisolone to a rat via a sterile subcutaneous injection in the dorsal scruff using a 27‑30 G needle, delivering the calculated dose based on body weight in a volume not exceeding 0.1 ml per gram. Ensure the animal is gently restrained, the injection site is cleaned with alcohol, and the needle is withdrawn smoothly to minimize tissue trauma.

How should a rat be given a prednisolone injection? - in detail

Administering prednisolone to a laboratory rat requires precise preparation, correct dosing, and aseptic technique. Follow these steps to ensure accurate and humane delivery.

1. Dose calculation

   • Determine the required dose in mg/kg based on the experimental protocol.
   • Multiply the animal’s weight (in kilograms) by the dose to obtain the total milligrams needed.
   • Convert the amount to the volume of the prepared solution, using the concentration of the prednisolone stock (e.g., 5 mg/mL).

2. Solution preparation

   • Dissolve prednisolone in a sterile, isotonic carrier such as 0.9 % saline or phosphate‑buffered saline.
   • Filter the solution through a 0.22 µm syringe filter to remove particulates.
   • Label the syringe with drug name, concentration, dose, date, and researcher’s initials.

3. Equipment

   • Use a 1‑mL tuberculin syringe with a 27‑30‑gauge needle.
   • Prepare a clean work surface and wear disposable gloves.

4. Animal restraint

   • Place the rat in a soft, breathable restraining bag or use a manual grip technique: hold the animal by the base of the tail, support the forelimbs against the palm, and keep the head elevated.
   • Ensure the rat is fully immobilized but not crushed; monitor for signs of distress.

5. Injection site selection

   • Preferred sites: subcutaneous (over the dorsal cervical region) or intraperitoneal (lower right quadrant).
   • For subcutaneous injection, lift a fold of skin to create a tent; insert the needle at a 45° angle, bevel up.
   • For intraperitoneal injection, insert the needle at a 30° angle into the right lower quadrant, avoiding the liver and spleen.

6. Administration

   • Depress the plunger smoothly to deliver the calculated volume.
   • Withdraw the needle gently, apply light pressure with sterile gauze to the puncture site to prevent leakage.

7. Post‑injection monitoring

   • Observe the rat for at least 15 minutes for abnormal behavior, respiratory distress, or signs of pain.
   • Record injection time, site, volume, and any immediate reactions in the study log.

8. Safety and waste disposal

   • Discard used needles in a designated sharps container.
   • Dispose of the remaining solution according to institutional hazardous waste guidelines.

Adhering to these procedures guarantees accurate dosing, minimizes tissue irritation, and upholds animal welfare standards.