How to rinse a rat’s stomach? - briefly
Anesthetize the rat, insert a lubricated catheter through the esophagus into the stomach, and gently infuse sterile saline (approximately 10 ml per kilogram) until the outflow is clear. Collect the expelled fluid in a sterile container for analysis or dispose of it following biosafety guidelines.
How to rinse a rat’s stomach? - in detail
A gastric lavage for a laboratory rat requires sterile equipment, a calibrated syringe, and a flexible tubing set designed for small mammals. The procedure should be performed by trained personnel under a approved animal use protocol.
Materials
- 1 ml or 2 ml syringe with a 23‑25 G catheter or oral gavage needle
- Sterile isotonic saline (0.9 % NaCl) pre‑warmed to 37 °C
- Disposable gloves, lab coat, and eye protection
- Anesthesia machine or inhalant agent (e.g., isoflurane)
- Absorbent pads and a clean work surface
Preparation
- Verify that the animal’s weight is recorded; calculate the lavage volume (approximately 5 ml kg⁻¹).
- Anesthetize the rat to a surgical plane; confirm lack of reflexes.
- Position the animal in dorsal recumbency with the head slightly elevated to prevent aspiration.
Procedure
- Attach the catheter to the syringe, expel any air bubbles.
- Gently insert the catheter through the oral cavity, directing it along the midline of the esophagus.
- Advance until resistance is felt at the gastro‑esophageal junction; do not force further.
- Slowly inject the calculated saline volume, allowing it to fill the stomach.
- After the full volume is delivered, pause for 10–15 seconds to let the fluid mix with gastric contents.
- Re‑aspirate the fluid by pulling the plunger back gently; repeat the inject‑aspirate cycle once more if needed to clear residual material.
- Withdraw the catheter carefully, avoiding trauma to the oral tissues.
Post‑procedure care
- Monitor respiration and responsiveness until the animal regains normal activity.
- Return the rat to a warm recovery cage; observe for signs of distress, bleeding, or vomiting.
- Record the volume of fluid recovered and any abnormalities noted during the lavage.
Precautions
- Use only sterile saline; contaminated solutions can introduce infection.
- Do not exceed the recommended volume, as over‑distension may cause gastric rupture.
- Maintain the catheter tip free of debris; a blocked tip compromises flow and can damage the esophagus.
- Ensure the animal remains under adequate anesthesia throughout; spontaneous movement increases the risk of injury.
By adhering to these steps, the gastric cavity can be effectively flushed, providing a clean sample for downstream analysis while minimizing animal discomfort and procedural complications.