How does rat castration proceed? - briefly
The animal is first placed under appropriate anesthesia (typically isoflurane or injectable agents) to eliminate pain and reflexes. A scrotal or ventral incision is made, the testes are exteriorized, the spermatic cords are ligated and removed, hemostasis is secured, and the incision is closed with sutures or tissue adhesive.
How does rat castration proceed? - in detail
The surgical removal of the testes in male rodents follows a standardized protocol designed to minimize pain and ensure reproducibility.
Before beginning, select healthy adult rats, verify weight (250–350 g) and confirm no underlying disease. House animals individually for at least 24 hours to reduce stress. Prepare a sterile work area, arrange a surgical tray with scalpel, fine scissors, forceps, gauze, suture material (4‑0 or 5‑0 absorbable), and a heat source for maintaining body temperature.
Administer anesthesia using an injectable combination (e.g., ketamine 80 mg/kg and xylazine 10 mg/kg) or an inhalation system (isoflurane 2–3 % in oxygen). Confirm depth of anesthesia by lack of pedal reflex. Apply a sterile ophthalmic lubricant to prevent corneal drying. Place the rat on a heated pad, dorsal side up, and secure the hind limbs with tape or a small restraining device.
Perform a midline or bilateral scrotal incision:
- Disinfect the scrotal skin with 70 % ethanol followed by povidone‑iodine.
- Make a 5–7 mm longitudinal skin cut over each testis, avoiding excessive tension.
- Expose the tunica vaginalis, open it gently, and exteriorize the testis with the epididymis.
- Ligate the spermatic cord using a single 4‑0 absorbable suture placed 2–3 mm distal to the testis.
- Cut the cord distal to the ligature, removing the testis.
- Repeat the procedure on the contralateral side.
Close the incision by approximating the skin edges with a simple interrupted or continuous absorbable suture. Apply a thin layer of sterile petroleum jelly to the wound to reduce drying.
Post‑operative care includes:
- Administering analgesics (e.g., buprenorphine 0.05 mg/kg subcutaneously every 12 hours for 48 hours).
- Monitoring recovery from anesthesia, ensuring normal respiration and mobility.
- Providing softened food and water ad libitum.
- Inspecting the surgical site daily for signs of infection or dehiscence.
Euthanasia or further experimental procedures should be scheduled only after the animal has fully recovered, typically 7–10 days post‑surgery. This regimen delivers consistent outcomes while adhering to ethical standards for animal welfare.