How should a bitter medicine be given to a rat? - briefly
Mix the bitter compound with a sweet carrier such as a sucrose solution or flavored gelatin and deliver the exact dose by oral gavage or by incorporating it into the rat’s feed. Verify ingestion by monitoring consumption or by confirming drug levels in a post‑administration blood sample.
How should a bitter medicine be given to a rat? - in detail
Administering a bitter compound to a laboratory rat requires precise preparation, appropriate delivery technique, and strict adherence to animal‑care guidelines.
First, calculate the dose based on the animal’s body weight. Use the formula dose (mg) = target mg kg⁻¹ × weight (g) ÷ 1000. Prepare a solution whose concentration allows the entire dose to be delivered in a volume not exceeding 10 mL kg⁻¹ (typically 0.2–0.5 mL for a 250‑g rat). Dissolve the bitter agent in a suitable vehicle—distilled water, saline, or a low‑viscosity oil—ensuring complete solubility and stability. Adjust pH to a neutral range (6.5–7.5) to minimize gastric irritation.
Second, select the delivery method. The most reliable approach is oral gavage with a calibrated feeding needle:
- Restrain the rat gently using a tail‑hold or a restraining device; avoid excessive pressure that could cause stress or injury.
- Insert the gavage needle along the midline of the tongue, advancing until the tip reaches the esophagus (approximately the length of the animal’s snout).
- Deliver the calculated volume slowly (≈ 0.5 mL s⁻¹) to prevent regurgitation or aspiration.
- Withdraw the needle smoothly and observe the rat for at least five minutes, monitoring breathing and behavior for signs of distress.
If repeated dosing is required, consider habituating the animals to the procedure to reduce stress. An alternative is to incorporate the bitter solution into palatable food or a flavored gel, but this method demands validation of intake consistency; otherwise, dose accuracy may be compromised.
Finally, document all steps: animal identification, weight, calculated dose, solution concentration, administration time, and any adverse reactions. Ensure the protocol is approved by the institutional animal‑care committee and that personnel are trained in gavage technique.