How to correctly give medicine to a rat? - briefly
Administer the medication by oral gavage with a calibrated syringe and blunt feeding needle, gently restraining the rat and delivering the exact weight‑adjusted dose. Alternatively, mix the drug into a palatable food or water source, confirming complete ingestion before returning the animal to its cage.
How to correctly give medicine to a rat? - in detail
Administering medication to a laboratory rat requires precise preparation, appropriate handling, and strict adherence to aseptic technique.
First, determine the correct dose. Convert the prescribed amount (mg/kg) to the animal’s weight (g) using the formula: dose (mg) = dose (mg/kg) × weight (g) / 1000. Prepare the solution or suspension in a sterile container, ensuring the final concentration allows delivery of the calculated volume with a standard syringe (e.g., 0.1–0.2 mL for a 250 g rat).
Select the route that matches the drug’s pharmacokinetics and study design:
- Oral gavage – use a flexible, blunt‑ended gavage needle (1–2 mm diameter). Lubricate the needle, gently insert it along the palate, and advance to the esophagus without forcing. Deliver the measured volume slowly to avoid aspiration.
- Subcutaneous injection – pinch a loose area of skin on the dorsal flank, insert a 25‑27 G needle at a shallow angle, and inject the solution steadily. Observe for leakage or swelling.
- Intraperitoneal injection – locate the lower right quadrant of the abdomen, insert a 25‑27 G needle at a 30‑45° angle, and aspirate to confirm entry into the peritoneal cavity before delivering the dose.
- In‑feed or in‑water administration – dissolve or suspend the drug in the appropriate amount of chow or drinking water, verify homogeneity, and monitor consumption daily to ensure the intended intake.
Restraint must be brief and humane. Use a gentle scruff technique or a specialized restraining device, keeping the animal’s stress to a minimum. Maintain a clean work surface; disinfect all equipment before and after use with an appropriate antiseptic (e.g., 70 % ethanol).
After dosing, observe the rat for at least 30 minutes. Record any adverse reactions, injection site condition, and the exact time of administration. Store remaining medication according to the manufacturer’s guidelines, noting expiration dates.
Finally, document all steps in the animal’s study log, including weight, calculated dose, route, volume administered, and observations. This record ensures reproducibility and compliance with institutional animal care protocols.