These include an enlarged prostate gland, enlarged mammary glands and nipples, symmetrical hair loss, anemia, and the tendency to attract other male dogs. Seminomas will also appear as swellings of the testicle, scrotum and inguinal or abdominal area. Interstitial cell tumors show very few symptoms and do not produce estrogen or metastasize. They are usually incidental findings and not considered to be much of a problem. Diagnosis is based on history, presentation, and pathological identification through a biopsy or microscopic examination of the removed tumor.
Treatment usually consists of surgical castration.
Because of the success of testicular removal and the low rate of metastasis, castration is often the only treatment needed. Some dogs have been treated successfully with chemotherapy and in dogs that have metastasis, chemotherapy is sometimes recommended. The prognosis for dogs with treated testicular cancer is usually very good. The low rate of metastasis makes surgical castration very successful and curative in most dogs. Dogs that develop hyperestrogenism from Sertoli cell tumors will often have a regression of symptoms, once the tumor has been removed.