How do you treat an abscess in a rat? - briefly
Administer a broad‑spectrum antibiotic (e.g., enrofloxacin or amoxicillin‑clavulanic acid) after confirming the infection, and surgically incise and drain the abscess under aseptic conditions, followed by regular wound cleaning and supportive care.
How do you treat an abscess in a rat? - in detail
Treating a purulent lesion in a laboratory rat requires a systematic approach to ensure effective resolution and minimize recurrence.
First, confirm the presence of an abscess by palpation and, if necessary, ultrasonography. Look for a localized, fluctuant mass with surrounding erythema or heat. Collect a sample of the exudate for culture and sensitivity before intervention.
Prepare the animal by fasting for 2–4 hours, then induce anesthesia using isoflurane (induction at 4–5 % in oxygen, maintenance at 1–2 %). Maintain body temperature with a warming pad throughout the procedure.
Follow strict aseptic technique: shave the area, apply a disinfectant such as 70 % ethanol followed by povidone‑iodine, and drape the site with sterile gauze. Use a sterile scalpel or fine scissors to make a small incision over the most dependent part of the cavity. Gently express the pus with sterile forceps or a blunt probe, avoiding rupture of surrounding tissue.
Debride necrotic material using fine curettes. Irrigate the cavity repeatedly with sterile saline until the effluent runs clear. If the cavity is large, consider placing a small, sterile drainage tube (e.g., a 22‑gauge catheter) secured with sutures to allow continuous drainage.
Select an antimicrobial regimen based on culture results; empiric therapy may start with enrofloxacin (10 mg/kg subcutaneously once daily) or a combination of ampicillin (30 mg/kg intraperitoneally twice daily) and metronidazole (15 mg/kg subcutaneously twice daily) pending susceptibility data. Administer the first dose intra‑operatively, then continue for 7–10 days.
Close the skin with interrupted 5‑0 absorbable sutures or leave it open if extensive drainage is required. Apply a sterile, non‑adherent dressing if needed. Provide analgesia with meloxicam (1 mg/kg subcutaneously every 24 h) for 48–72 hours.
Monitor the rat daily for signs of pain, swelling, or discharge. Record weight, temperature, and behavior. Remove sutures or drainage devices after 3–5 days, provided the site remains clean and non‑inflamed.
Document all observations, culture results, and treatment adjustments. Proper record‑keeping facilitates reproducibility and compliance with institutional animal care guidelines.