How do you rinse a rat's nose with chlorhexidine? - briefly
Prepare a 0.05 % solution of «chlorhexidine» in sterile saline, anesthetize the rat, and gently flush each nostril with a calibrated micropipette delivering 10 µL of the solution. Use a slow flow rate to prevent mucosal injury and observe the animal for any signs of respiratory distress.
How do you rinse a rat's nose with chlorhexidine? - in detail
A detailed protocol for flushing a rodent’s nasal passage with chlorhexidine requires aseptic preparation, appropriate anaesthesia, precise instrumentation, and post‑procedure monitoring.
Materials and reagents
- Sterile 0.05 % chlorhexidine gluconate solution, prepared in physiological saline
- Isoflurane vapour delivery system or injectable anaesthetic (e.g., ketamine/xylazine)
- Small‑volume syringe (1 ml) fitted with a flexible, blunt‑ended catheter (23‑24 G)
- Sterile gauze pads, absorbent paper, and disposable gloves
- Warmed recovery cage with supplemental oxygen
Preparation
- Verify concentration of chlorhexidine; a 0.05 % solution balances antimicrobial efficacy with minimal mucosal irritation.
- Warm the solution to 37 °C to prevent hypothermia and reduce vasoconstriction.
- Calibrate the syringe to deliver 0.1 ml per nostril, adjusting volume for the animal’s size (approximately 200–250 g).
Anaesthesia
- Induce a surgical plane of anaesthesia using isoflurane (2–3 % in oxygen) or an injectable cocktail, confirming the absence of reflexes.
- Maintain body temperature with a heating pad throughout the procedure.
Technique
- Position the animal supine on a sterile surface, head slightly elevated.
- Gently insert the catheter into one nostril, advancing no more than 2 mm to avoid trauma to the turbinates.
- Inject 0.1 ml of the chlorhexidine solution at a steady rate, allowing the fluid to flow through the nasal cavity and exit the opposite nostril.
- Repeat the process for the contralateral nostril using a fresh catheter.
- After each flush, use sterile gauze to absorb excess fluid and prevent aspiration.
Post‑procedure care
- Observe the animal until full recovery of righting reflexes, monitoring for signs of respiratory distress or epistaxis.
- Provide supplemental oxygen for 5–10 minutes if needed.
- Return the rat to a warmed cage with easy access to food and water.
- Document the procedure, including solution concentration, volume administered, and any adverse observations.
Safety considerations
- Handle chlorhexidine with gloves; avoid skin contact and inhalation of vapours.
- Dispose of used catheters and gauze in biohazard containers.
- Ensure that the anaesthetic depth is sufficient to prevent coughing or gagging, which could compromise the flush.
The described method delivers a controlled, reproducible nasal rinse, achieving decontamination of the upper respiratory tract while minimizing tissue damage.