A 13 year old, intact male Shih Tzu was first noted to have an enlargement of the left testicle in mid-December 2011. Abdominal and testicular ultrasound on 1/9/12 revealed highly vascular abnormal tissue composing the left testicle, a right intra-testicular mass composed of similar abnormal tissue and enlarged, cystic right hypogastric and left medial iliac lymph nodes. The patient was presented to the Cornell University Hospital for Animals’ Oncology Service on 1/19/2012. Based on the abnormalities detected on the initial physical exam and minimum database, combined with the patient’s history, neoplasia was at the top of the differential diagnosis list. There was no radiographic evidence of pulmonary metastasis. Abdominal ultrasound confirmed previous findings and suggested possible progression of disease. Aspirates taken were interpreted as presumptive metastatic seminoma, and later confirmed with histopathology of the testis. Most primary testicular tumors in dogs remain locally confined, with regional or distant metastasis being uncommon, therefore knowledge pertaining to the efficacy of available modalities is limited.