Testicular Lump in Neutered Dogs: Could It Be a Tumor?

At Erawan Pet Hospital, we recently treated an 8-year-old dog whose owner noticed an unusual swelling and firm lump in the scrotal area—even though the dog had been neutered years ago.

Upon reviewing the dog’s medical history, we found that the neutering had been performed during his younger years. However, the mass appeared to be located in the same region as the testes.


Diagnosis and Findings
After a physical examination and ultrasound imaging, our veterinary team suspected that the lump was either:
- A tumor arising from retained testicular tissue, or
- Incomplete removal of the testicular tissue during the previous neutering procedure.

While such cases are uncommon, they can occur, especially in dogs with cryptorchidism (undescended testicles) or cases where some testicular tissue remains after neutering.

Risk of Testicular Tumors in Neutered Dogs
Even in neutered dogs, retained or abnormal testicular tissue can develop tumors—some of which may become malignant. These tumors can produce abnormal hormones, affecting overall health. Potential consequences include:
- Hormonal imbalances (e.g., enlarged mammary glands, hair loss)
- Tumor metastasis to lymph nodes or internal organs
- Anemia or general weakness if cancer has spread

Surgical Risks in Senior Dogs
Although testicular tumor removal is a common procedure, older dogs—like this case—require special consideration. Key risks include:
- Anesthesia-related complications: Liver, kidney, and heart function must be carefully evaluated before surgery.
- Excessive bleeding: Some tumors have rich blood supplies and require meticulous surgical technique.
- Post-operative infection: Particularly when the mass is large or already inflamed.
- If cancer is confirmed, follow-up treatment (e.g., chemotherapy or long-term monitoring) may be required.

Surgical Plan and Post-Operative Care
Our veterinary surgeons carefully planned the procedure using techniques tailored for senior dogs. Throughout anesthesia and surgery, the patient’s vital signs were closely monitored.

After surgery, the dog was placed in a temperature-controlled recovery room and cared for by our 24-hour veterinary nursing team. Pain management, medication, and regular post-op monitoring were all provided to ensure a smooth recovery.

Specialized Care from Our Advanced Veterinary Oncology Department
Cancer in pets is more common than many owners realize. At Erawan Pet Hospital, our Veterinary Oncology Center is fully equipped to provide specialized cancer care, including:
- Histopathology (biopsy) analysis
- X-ray and ultrasound imaging to assess cancer spread
- Collaborative treatment planning with our surgery, anesthesia, and rehabilitation teams

From diagnosis through to recovery, we’re here to provide holistic, expert care for your beloved pets.