Inguinal Cryptorchid Castration

Retained testicles should always be removed — the two major reasons are cancer risk and genetic inheritance:

• Cancer risk: a cryptorchid testicle is exposed to higher core body temperature than a normally descended testicle, which dramatically increases its lifetime risk of becoming cancerous — Sertoli cell tumors and seminomas are the most common, and they can produce excess estrogen causing serious hormonal complications
• Hormonal effects: even if retained, the testicle still produces testosterone and estrogen (depending on tumor type), which can cause prostatic enlargement, perineal hernias, and other testosterone-driven problems in dogs
• Hereditary condition: cryptorchidism is inherited; affected males should not be bred, as they pass the trait to their offspring

Watchful waiting is not recommended — the risk of malignant transformation in a retained testicle climbs significantly with age, and surgical removal is far simpler before tumor development occurs.

Inguinal cryptorchid castration requires locating and removing the retained testicle in addition to a routine scrotal castration. The procedure steps include:

• The normally descended testicle (if present) is removed through the pre-scrotal or scrotal approach in the standard manner
• An incision is made over the inguinal region where the retained testicle has been localized by palpation or ultrasound
• The testicle is carefully identified and freed from surrounding tissue, including any attachment to the inguinal ring or spermatic cord
• The spermatic cord is ligated (tied off) and the testicle is removed
• The incision is closed in layers; the inguinal ring is often partially closed to prevent herniation

If the testicle cannot be found in the inguinal region during surgery — indicating it may be intra-abdominal — the exploration is extended or a separate abdominal approach is used. Pre-operative ultrasound by our imaging team helps localize the testicle before surgery begins.

Pre-operative preparation for inguinal cryptorchid castration includes:

• Careful palpation of the inguinal region and scrotum to determine how many testicles are present and where the retained one is located
• Abdominal and inguinal ultrasound to localize the retained testicle precisely before the patient goes to surgery — this is especially helpful for small or deep testicles and avoids unnecessary exploration
• Pre-anesthetic bloodwork appropriate for age and health status
• If a tumor is suspected based on signs of excess estrogen (symmetrical hair loss, gynecomastia, bone marrow suppression), additional bloodwork including a complete blood count is essential
• Food withheld the night before surgery

Most dogs and cats recover from cryptorchid castration quickly, though the inguinal incision requires slightly more attention than a routine scrotal castration:

• Entire healing period (10–14 days): e-collar worn continuously to prevent licking at both incision sites
• Days 1–7: mild swelling at the inguinal incision is normal; ice packing for twenty-four hours reduces it
• Days 1–14: leash walks only; restrict jumping and running
• 10–14 days: recheck appointment for suture or staple removal and wound assessment

Pets with Sertoli cell tumors and signs of excess estrogen production may take four to six weeks before hormonal effects (hair loss, bone marrow depression) begin to reverse after tumor removal.

Inguinal cryptorchid castration is a safe, well-established procedure. Risks are generally low but include:

• Inability to find the testicle in the inguinal region, necessitating abdominal exploration in the same or a subsequent surgery — uncommon when ultrasound localization is performed beforehand
• Seroma or hematoma at the inguinal incision — more common here than at a scrotal site due to the presence of fat and lymphatics in the groin
• Inguinal hernia at the surgical site — rare; the inguinal ring is partially closed during surgery to reduce this risk
• For animals with a Sertoli cell tumor: bone marrow suppression from excess estrogen may require additional monitoring and supportive care post-operatively

With prompt removal before tumor development, the prognosis is excellent. Even when a Sertoli cell tumor is present at the time of surgery, most dogs recover fully once the hormonal source is removed.