How to drip a rat’s eyes? - briefly
Apply a sterile isotonic saline solution to the rat’s conjunctival sac using a calibrated micropipette, allowing the fluid to coat the cornea and elicit tear flow. Conduct the procedure under appropriate anesthesia and in compliance with institutional animal‑care regulations.
How to drip a rat’s eyes? - in detail
Administering eye drops to a laboratory rat requires precise technique to ensure accurate dosing and minimize distress. The following protocol outlines the necessary equipment, preparation steps, execution, and post‑application care.
Equipment
- Sterile ophthalmic solution in a calibrated micro‑pipette or dropper (0.5 µL – 5 µL per eye)
- Fine‑point forceps or a restraining tube designed for rodents
- Disposable gloves, mask, and lab coat for aseptic handling
- Cotton swabs or sterile gauze for excess fluid removal
- Light source with adjustable intensity to illuminate the ocular surface
Preparation
- Verify solution sterility and expiration date; warm to room temperature (20‑22 °C) to prevent corneal shock.
- Calibrate the dispensing device; confirm volume by delivering a test drop onto a sterile slide.
- Place the rat in a clean, quiet area; allow acclimation for at least five minutes to reduce stress.
Procedure
- Secure the animal using a gentle restraint method: a transparent tube with a narrow opening permits head access while limiting movement, or hold the forepaws with fine forceps while supporting the body.
- Position the rat’s head so the eye faces upward; use the light source to visualize the cornea clearly.
- Gently pull the lower eyelid downward with a sterile cotton swab to form a small pocket.
- Deliver the predetermined volume directly onto the corneal surface, avoiding contact between the tip and the eye.
- Release the lower lid, allowing the drop to spread naturally; wait two to three seconds before repeating on the opposite eye if required.
- If excess fluid accumulates, absorb with a sterile gauze without pressing on the globe.
Post‑application care
- Return the rat to its cage; monitor for signs of discomfort, excessive tearing, or blinking abnormalities for at least ten minutes.
- Record the administered dose, time, and any observed reactions in the experimental log.
- Clean all reusable equipment with appropriate disinfectant before storage.
Troubleshooting
- Inadequate drop placement often results from excessive restraint pressure; adjust grip to maintain a relaxed posture.
- Droplet loss may occur if the tip is too close to the cornea; maintain a 1–2 mm distance.
- Corneal opacity or ulceration indicates possible overdose or contamination; discontinue the procedure and consult veterinary staff immediately.
Adhering to this systematic approach ensures consistent ocular delivery while safeguarding animal welfare.