How should ear drops be administered to a rat? - briefly
Hold the rat securely, tilt its head to open the external auditory canal, and dispense the exact measured volume of otic solution with a calibrated pipette, allowing the animal to remain still for at least 30 seconds to ensure absorption. Verify that the ear is free of debris before application and monitor the rat briefly afterward for any adverse reaction.
How should ear drops be administered to a rat? - in detail
Accurate delivery of otic medication to a laboratory rat requires careful preparation, precise dosing, and controlled handling.
Begin by selecting a sterile, calibrated dropper or micropipette capable of dispensing volumes as low as 5 µL. Verify the concentration of the ear‑drop formulation and calculate the required dose based on the animal’s weight (typical dose: 0.1 mL kg⁻¹, not exceeding 5 µL per ear). Prepare a clean work surface, gather gloves, sterile gauze, and a soft restraining device (e.g., a small Plexiglas tube or a hand‑held blanket).
Restrain the rat gently but firmly to prevent movement. Place the animal in a supine position on a padded surface; the head should be slightly elevated to open the external auditory canal. Using a fine forceps, lift the outer ear flap (pinna) to expose the canal entrance. Hold the dropper vertically, avoiding contact with the skin, and release the calculated volume slowly into the canal. Allow the solution to flow by keeping the pinna held open for 10–15 seconds; if necessary, use a sterile cotton swab to distribute the fluid evenly without inserting it into the canal.
Repeat the procedure for the opposite ear if bilateral treatment is required, ensuring the same dose and technique. After administration, observe the rat for any signs of distress, excessive shaking, or abnormal grooming of the ears. Record the time of dosing, volume administered, and any immediate reactions in the animal’s log.
Dispose of used materials according to biosafety protocols, and clean the work area with an appropriate disinfectant. Regularly inspect the ear canal for inflammation, discharge, or blockage during subsequent examinations to confirm therapeutic efficacy and detect adverse effects early.