Testicular Tumors In Dogs

The male dog reproductive tract consists of the scrotum, the two testes (located inside the scrotal sac), the epididymis, the spermatic cords, the ductus deferens (tube that starts from the epididymis, passes through prostate and empties into the urethra), the prostate (an accessory gland producing prostatic fluid, which helps maintain sperm passage into the female dog), the urethra (the general tube of semen and urine) and the penis.

The male gonads (testes) are directed craniocaudally, ellipsoid in shape and thicker in the center than on the sides. Each testis with its respective distal spermatic cord and epididymis is located within the scrotum. The right testis is less caudal than the left testis; this arrangement reduces pressure on each testis and permits the testes to slide along each other. The seminiferous tubules of the testicle produce spermatozoa.

The most common testicular malignancies are Interstitial (Leydig) cell tumors (50%), seminomas (40%) and Sertoli cell tumors (8%). These cancers comprise of almost 98% of overall testicular cancers in dogs. Other rare types of testicular tumors such as lipoma, hemangioma, fibroma, embryonal carcinoma, teratoma and chondroma. Seminomas are the most common benign testicular tumour in dogs. The interesting thing to note is that both testicles can be cancerous but can have different types of testicular cancer.

Similar to most canine cancers, the etiology of testicular tumors is still unidentified. Though, some of these tumors have been associated with the presence of prostatic disease and cryptorchidism, the contribution of testosterone is conclusive. Testicular cancer is one of the top five causes of cancer-related deaths in dogs.

• Swelling of either or both testicles
• Scrotal palpation (these masses are usually easy to palpate)
• Hematuria (Blood in the urine)
• Dysuria/ Stranguria (Difficulty urinating)
• Frequent attempts to urinate
• Spermatic cord torsion (a cord supplying blood to the testicle is twisted)
• Abnormal posture (especially while urinating)/ Abnormal gait
• Enlarged scrotum
• Testicular atrophy
• Pain/General weakness
• Fever
• Weight loss

• Primary tumors (diameter < 3cm): The most appropriate therapy for the non-metastasized primary tumors is local surgical excision. Radiotherapy may be used post-operatively to improve the tumor control.
• Primary tumors (> 3cm): When there is no evidence of metastasis, chemotherapy drugs can be used to attempt to shrink the tumor.
• IM/IGRTradiation therapy: Image-guided and intensity-modulated radiation therapy is a is a relatively new technique in which high-energy beams of radiation are employed using imaging technologies such as PET, MRI, and CT.
• Urinary obstruction: Palliative radiotherapy can be used as short term relief.
• Sublumbar lympadenopathy - Surgical removal of enlarged lymph nodes. This is performed in dogs with tumours that have spread only to the regional lymph nodes but no further.
• Any significant obstruction of the urethra: To keep open the urethra for urination, a surgical stent is placed.

• Once the surgery is over, activities of your dog should be restricted for about 2 weeks to allow recuperation and incision healing
• A restrictive e-collar can be used for 2 weeks
• Home-cooked diet, with wholesome, nutritious foods as an substitute to commercial diets

The causes for testicular tumour in dogs are mostly idiopathic and geriatric so prevention is not possible. Neutering the dogs is best way of prevention.

Seminomas:

• English Bulldog
• Fox Terrier
• Great Dane
• Keeshond
• Norwegian Elkhound
• Old English Sheepdog
• Scottish Terrier
• Siberian Husky
• Weimaraner

Sertoli Cell Tumors:

• Afghan Hound
• Airedale Terriers
• Fox Terrier
• Norwegian Elkhound
• Pekingese
• Shetland Sheepdog
• West Highland White Terriers
• Weimaraner

Interstitial Cell Tumors:

• Afghan Hound
• Bull Terrier
• Dalmatian
• Fox Terrier
• Old English Sheepdog
• Siberian Husky
• Shetland Sheepdog

1. Causes:

• Hereditary
• Older dogs - male dogs over eight years old
• Higher in intact dogs
• Exposure to toxic chemicals (1,4-dichlorobenzene, doxorubicin, phenylbutazone), pesticides and herbicides, nitrosamines, cyclophosphamide, etc

2. Types:

Primary testicular cancer: Cancer that starts off in the testicle region itself is called primary cancer. Most primary cancers are aggressive and are with high metastatic potential.

Secondary testicular cancer: Cancer that originates in another organ and spreads or metastasizes to the testicular region.

3. Mortality:

Benign types of Testicular tumour mortality rate are almost zero. Primary testicular tumour is highly aggressive and it should be diagnosed early as well as treated promptly. Unfortunately, it has high case fatality rate and < 50% of dogs survive more than 6 months from the time of diagnosis of primary types of cancer.

4. Prognosis:

Prognosis can fluctuate depending on the time of diagnosis and severity of the testicular tumour. In general, if the tumor is diagnosed early on, prior to any metastasis, chemotherapy and radiation treatment may be effective. If there is any significant metastasis, vets may suggest against traditional treatment and will provide treatments to pacify the dog’s clinical signs to make them feel better.

Contact your vet right away, if you notice any of the following:

• Swelling of either or both testicles
• Hematuria (Blood in the urine)
• Dysuria/ Stranguria (Difficulty urinating)

• High Protein, Low Carbs, Good Fats and antioxidants and cancer-fighting nutrients
• Protein should comprise 40% of dogs’ calories. Fresh, lean protein (Lean white fish such as cod, grouper, haddock, lean cuts of beef, pork loin)
• Fats: Salmon, herring, mackerel, lake trout, tuna and sardines
• Vitamin-rich fruits and veggies: Legumes, snap peas, green beans, carrots, cauliflower, broccoli, cabbage, tomatoes, citrus fruits, Blueberries, strawberries, cherries etc

Testicular tumour prognosis for recovery is good, if it is detected early and before any metastasis has happened. In this case, survival time can be extended with more definitive treatment. If the cancer has metastasized to distant regions, management of disease symptomatically is often performed as long as possible.

The chances of recovery for metastasized testicular cancer are poor. Once quality of life has declined or clinical signs cannot be controlled, Euthanasia may be required.