How is a tumor removed from a rat? - briefly
The procedure involves anesthetizing the animal, making a sterile incision over the tumor, dissecting the mass from surrounding tissue with microsurgical instruments, and closing the wound with sutures or tissue glue. Post‑operative analgesia and monitoring are then administered to ensure recovery.
How is a tumor removed from a rat? - in detail
The excision of a neoplastic growth in a laboratory rat follows a standardized surgical protocol to ensure reproducibility and animal welfare.
First, the animal is anesthetized using an injectable agent such as ketamine‑xylazine or an inhalant like isoflurane. Depth of anesthesia is confirmed by the absence of pedal reflex and stable respiratory rate. The rat is then placed on a heated surgical platform, and the dorsal or ventral region containing the mass is shaved and disinfected with alternating applications of 70 % ethanol and povidone‑iodine.
A sterile drape isolates the operative field. A small incision (approximately 5–10 mm) is made through the skin and underlying fascia using a scalpel blade No. 11. Blunt dissection with fine forceps separates subcutaneous tissue to expose the tumor capsule. If the lesion is adherent to surrounding structures, careful sharp dissection with microsurgical scissors is employed to delineate margins.
The tumor is mobilized by grasping the capsule with micro‑forceps. A margin of 2–3 mm of normal tissue is excised together with the mass to achieve complete removal. Hemostasis is attained with sterile cotton swabs or low‑temperature electrocautery. The wound is closed in two layers: the fascia with absorbable 5‑0 sutures (e.g., Vicryl) and the skin with non‑absorbable 5‑0 monofilament (e.g., nylon) or surgical glue.
Post‑operative care includes placement of the rat in a recovery cage with warming, administration of analgesics (e.g., buprenorphine 0.05 mg/kg subcutaneously every 12 h for 48 h), and monitoring for signs of infection or dehiscence. The excised tissue is immediately fixed in 10 % neutral‑buffered formalin for histopathological verification of tumor type and margin status.
Documentation of anesthesia dosage, surgical times, intra‑operative observations, and post‑operative outcomes is essential for experimental reproducibility and ethical compliance.