How to properly administer medicine to a rat? - briefly
Use a calibrated oral gavage needle or a fine‑gauge syringe to deliver the precise, weight‑adjusted dose directly into the rat’s mouth while gently restraining the animal. After dosing, observe the subject for any immediate adverse reactions.
How to properly administer medicine to a rat? - in detail
Correct medication delivery to a laboratory rat requires precise preparation, handling, and observation. Begin with dose calculation: determine the animal’s weight in grams, consult the drug’s concentration, and compute the required volume using the formula dose (mg/kg) × weight (kg) ÷ concentration (mg/mL). Record the exact figure and verify with a second researcher.
Select the appropriate route. Oral gavage demands a smooth, rounded feeding needle sized for the rat’s body length; insert gently along the palate, avoiding the esophagus. Intraperitoneal injection uses a 25‑27 G needle, inserted at a 30‑45° angle into the lower right quadrant of the abdomen, taking care to avoid the intestines. Subcutaneous administration involves a shallow angle (10‑15°) into the loose skin over the dorsal neck region. Intramuscular injection requires placement into the quadriceps or hind‑limb muscle, with a 27‑30 G needle and a perpendicular entry.
Prepare the equipment: sterile syringes, appropriate needles, a calibrated balance, and a clean work surface. Disinfect the injection site with 70 % ethanol and allow it to dry. Warm the drug to the animal’s body temperature if it is a liquid formulation; avoid excessive heat that could degrade the compound.
During administration, restrain the rat with minimal stress. Use a manual restraint or a well‑ventilated tube, keeping the animal’s head elevated for oral dosing. Inject the calculated volume slowly, typically 0.1 mL per 10 g body weight, to prevent tissue damage. After delivery, observe the rat for at least 15 minutes, noting any abnormal behavior, respiratory distress, or signs of pain.
Record all details: drug name, concentration, administered volume, route, time, and any immediate reactions. Store the documentation with the animal’s health log for future reference and regulatory compliance.