Dog Testicular Tumor Prevention and Early Detection

Testicular tumors are among the most common tumors in intact male dogs, and prevention through castration eliminates the risk entirely.

Key Facts

Testicular tumors are the second most common neoplasm in intact male dogs
Three tumor types predominate: Sertoli cell tumor, seminoma, and interstitial (Leydig) cell tumor
Cryptorchid (retained) testicles have 10-14 times higher risk of neoplastic transformation
Sertoli cell tumors can produce estrogen, causing feminization syndrome including bone marrow suppression
Most testicular tumors are cured by castration; metastasis occurs in less than 15% of cases
Older intact male dogs should have testicles examined at every wellness visit
Scrotal ultrasound can detect tumors before they are palpable externally

Welfare Considerations

Cryptorchid males left intact face very high tumor risk that causes progressive hormonal disruption and, in some cases, potentially fatal bone marrow suppression from estrogen excess. Castration at the time of cryptorchidism correction eliminates this risk entirely. Owners of intact males should understand that testicular examination is a routine and important part of wellness care.

What You Can Do

Castrate cryptorchid male dogs at the time of corrective surgery to prevent tumor development
Request testicular examination as part of every wellness visit for intact males
Seek veterinary evaluation promptly for any scrotal swelling or size asymmetry in intact males
Discuss the benefits of castration for intact males in preventing testicular and some prostate conditions
Ask about scrotal ultrasound for elderly intact males as a screening tool