Veterinary Society of
Surgical Oncology

General Considerations

  • penile tumors account for 0.24% of all tumors in male dogs
  • SCC and transmissible venereal tumor most common are the most common tumors of the penis and prepuce
  • other types include MCT, LSA, FSA, histiocytic reticulocytoma, TCC, CSA, fibroma, and papilloma
  • LSA has been reported in association with penile prolapse in 1 dog
  • OSA, osteoma, and multilobular osteochondrosarcoma have been reported in the os penis
  • leishmaniasis can cause nodular penile mucosal lesions
  • penile tumors usually occur in older dogs
  • transmissible venereal tumors occurs in 4-5-year-old dogs with increased risk in free roaming dogs
  • transmissible venereal tumors are transmitted by contact with genital mucous membranes during coitus
  • transmissible venereal tumors appear as multiple tumors along the penis and mucosal lining of the prepuce


Clinical Signs

  • preputial enlargement with frequent licking of the penis and prepuce
  • stranguria, dysuria, and hematuria
  • serosanguineous or hemorrhagic preputial discharge as most tumors are friable and bleed easily
  • painful
  • ± urethral obstruction


  • physical examination
  • cytology from FNA or impression smear
  • histopathology from incisional or excisional biopsy


  • partial penile amputation
  • total penile amputation with scrotal urethrostomy ± penile urethrostomy if tumor extends into the proximal urethra
  • ventral midline preputiotomy for penile tumors that are large enough to allow penile extrusion through the preputial orifice (preputial splitting)
  • local tumor recurrence rate is high for dogs with transmissible venereal tumor and surgery is not recommended
  • transmissible venereal tumors are very response to chemotherapy and radiation therapy
  • chemotherapy: vincristine 0.5-0.7 mg/m 2 IV 4-8 times ± doxorubicin


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