How can activated charcoal be given to a rat? - briefly
Activated charcoal can be delivered to a laboratory rat either by oral gavage using a sterile feeding needle or by incorporating it into the animal’s food or drinking water. Typical dosing ranges from 1 g to 2 g per kilogram of body weight, administered as a single dose.
How can activated charcoal be given to a rat? - in detail
Activated charcoal can be delivered to a laboratory rat by oral, dietary, or rectal routes. Each method requires precise preparation, equipment, and monitoring to achieve reliable dosing and avoid complications.
A typical dose ranges from 1 to 2 g kg⁻¹ body weight, delivered as a homogeneous suspension in sterile water. Prepare the suspension immediately before use: weigh the required amount of charcoal, add warm distilled water to obtain a concentration of 20–30 mg ml⁻¹, stir vigorously, and pass the mixture through a fine mesh to eliminate aggregates. Use the suspension within 15 minutes to prevent sedimentation.
Oral gavage
- Restrain the rat in a gentle but firm grip; support the neck and back.
- Select a gavage needle (size 1.2 mm × 2 in for a 200‑g animal) with a rounded tip.
- Load the calculated volume (≈0.5 ml per 100 g) into a sterile syringe.
- Insert the needle along the palate, advance to the stomach without force, and slowly dispense the suspension.
- Observe the animal for signs of distress, regurgitation, or aspiration for at least 10 minutes.
Incorporation into food or water
- Mix the suspension into a palatable mash (e.g., softened chow) or dissolve in drinking water at a concentration that delivers the target dose based on average daily intake.
- Provide the mixture in a clean cage for a limited period (2–4 hours) to ensure consumption.
- Record the amount eaten or drunk to verify the administered dose.
Rectal administration
- Lubricate a flexible catheter (size 4 Fr) with sterile petroleum jelly.
- Gently insert the catheter 2–3 cm into the rectum, avoiding injury.
- Deliver 0.2–0.5 ml of the suspension, then withdraw the catheter slowly.
- Maintain the rat in a supine position for a few minutes to facilitate retention.
Post‑administration care
- Monitor body temperature, respiration, and activity for at least 30 minutes.
- Check feces for black, tarry material, confirming charcoal passage.
- Provide supportive fluids if dehydration is suspected.
Proper technique, accurate dosing, and vigilant observation are essential for successful administration of activated charcoal in rat studies.