Testicular Tumors and Implants

Should I be concerned that one of my dog’s testicles is larger than the other?

While some variation in size is normal, noticeable changes in the shape or size of the testicles should be examined by your veterinarian. Testicular tumors are the most common tumors that develop in the genitals of male dogs. One or both testicles may be affected.

What causes testicular tumors?

The current cause of testicular cancer is unknown. Although they are most common in intact male dogs over the age of 10 years, they can occur in intact males of any age and breed.

Male dogs that have one or both testicles that have not descended from the abdomen (cryptorchid) are at higher risk for developing testicular cancer than dogs with normally descended testicles in the scrotum. Tumors of normal-descended testicles are usually benign, while those still located in the abdomen are much more likely to be malignant. Malignant tumors are cancerous. They have the potential to spread and harmfully change the surrounding tissues. Cancerous tumors can also metastasize, or spread, to other organs throughout the body.

Are there different types of testicular tumors?

The three most common types of testicular tumors are Sertoli cell tumors, interstitial (Leydig) cell tumors and seminomas. More than one of these three types can occur in a cancerous testicle, and both testicles can be cancerous but have different types of testicular cancer. Other types of testicular tumors are rare and include embryonal carcinoma, lipoma, fibroma, hemangioma, chondroma and teratoma.

Sertoli cell tumors can produce the hormone estrogen, resulting in a condition called hyperestrogenism. Excess estrogen causes signs of feminization in male dogs. This includes enlarged mammary glands and nipples, a pendulous prepuce, hair loss and hyperpigmentation (darkening) of the skin. Hyperestrogenism can also affect the bone marrow, resulting in anemia (low red blood cell count), pale gums and lack of energy. Behavioral changes may include squatting to urinate, reduced libido and attraction of other male dogs.

Interstitial (Leydig) cell tumors are the most common type of testicular tumor. They are small, typically benign, and often found incidentally during a routine examination.

Seminomas arise from the cells of the testicle that produce sperm. The majority of seminomas are benign, and they rarely spread. These tumors may lead to signs of female characteristics in male dogs. They are more common in undescended testicles.

What are the signs of testicular tumors?

Many dogs show no obvious signs in the early stages. Symptoms can vary depending on the tumor type and location. Some warning signs include soft swelling in one or both testicles, asymmetrical or unevenly sized testicles, generalized scrotal enlargement, pain upon touching the testicles, and infertility in the breeding stud dog.

Other signs include the feminization characteristics and behavioral changes listed above. Some dogs will experience weight loss, poor appetite, belly pain or a mass in the abdomen.

How is a testicular tumor diagnosed?

Suspicion of a testicular tumor is based on the dog’s medical history and the abnormalities discovered during a physical examination. Tests such as a complete blood count (CBC), biochemistry profile, urinalysis, chest and abdominal X-rays, abdominal and scrotal ultrasound, fine-needle aspiration of the testicular mass and histopathology (biopsy) of the removed testicle may be recommended.

Is there treatment for testicular tumors?

The primary treatment for testicular tumors is castration, or surgical removal of the testicles. This surgery is called an orchiectomy. Both testicles need to be removed because the cancer may be present in both, even if only one is obviously affected. If a retained testicle is involved, it will be removed, requiring abdominal surgery, along with the normally descended one.

Complications following properly performed castrations are rare, but include problems with the incision if the dog is allowed to lick at the sutures and surgical site. These complications would be swelling, infection and bleeding in the scrotum.

A pathologist can assess the testicles after they are removed to determine the type of cancer. If your veterinarian is not comfortable treating the type of cancer, you may be referred to a veterinary oncologist. When the cancer has spread, additional treatments like chemotherapy or radiation therapy may be used.

If no evidence of metastasis has occurred and the dog is not showing any major tumor-related clinical signs, surgery is often curative and the only treatment needed. Only about 15 percent of testicular tumors metastasize, so the cure rate after surgery is extremely high.

Dogs that are severely affected by testicular tumors, such as those with bone-marrow disease, have a much poorer prognosis. Even with surgery, these dogs may not survive. The sooner surgery can be performed after noticing clinical signs or a change in the testicles, the better your dog’s chance of recovery will be.

Are there implants to replace the testicles after surgery?

Neuticles are prosthetic testicular implants for neutered dogs. Sizes are made for cats, horses and bulls as well. Some owners, especially with short-coated breeds, are uncomfortable with their pet’s appearance after surgical removal of the testicles. In 1993, Gregg Miller, along with a veterinarian, developed the idea for Neuticles and patented the procedure for implantation.

The implants are made of human-quality, FDA medically approved polypropylene or silicone. These are not gel- or saline-filled, but a rubber-like material that replicates the firmness of a natural testicle. Some models feature an anatomically correct recreation of the epididymis as well as a textured exterior, which virtually eliminates the risk of scar-tissue formation.

Neuticles are available in four models and multiple sizes for any sized dog. They may be purchased singly or in pairs. The cost ranges from approximately $250 for the smallest one to more than $700 for one of the XXLarge UltraPlus model.

Implantation is fairly straightforward but would be an additional cost. Written and video tutorials are available for veterinarians. There is also a form you can fill out to be referred to a veterinarian in your area who is familiar with the procedure.

According to their website, since the first implantation in 1995, more than 230,000 pets throughout the world — including dogs, cats, horses, monkeys, bulls, water buffalo and even rats — have received Neuticles without a single complication or pet-owner complaint. Wikipedia reports the company has produced customized prosthetic testicles, such as a $2,800 watermelon-sized set for an elephant.

They claim Neuticals are 100 percent safe and risk-free when implanted as directed. Unlike any medical product, Neuticles insures each pet for up to $2 million against any form of complication. This guarantee covers not only the pet, but the veterinarian performing the implantation and the clinic or hospital.