Case study: Bear, a German shepherd with an abdominal mass
Bear, an 8-year-old intact male German Shepherd, came to Cahaba Valley Animal Clinic after he had been vomiting and not eating for a few days. He had no diarrhea and there was no blood in his vomit.
Bear was bright, alert, and responsive, and he was of healthy weight. His eyes, ears, nose, and throat looked normal and healthy, as did his gums, skin, and coat. His heart and lungs sounded as they should. However, upon feeling Bear’s abdomen, Dr. Norris felt a large mass. She also noticed Bear was cryptorchid, meaning one or both of his testicles were not descended into the scrotal sac.
In most cases of cryptorchidism, the testicle is retained in the abdomen or the inguinal canal (the passage through the abdominal wall into the genital region through which the testicle normally descends). Sometimes, the testicle is located just under the skin in the groin region.
Normally, in the case of abdominal cryptorchidism, the testicle cannot be felt from the outside, and an abdominal ultrasound or radiographs (x-rays) are necessary to determine the exact location. However, Dr. Norris was able to feel Bear’s because, as she discovered later, his undescended testicle was enlarged.
When she looked at the initial ultrasound, Dr. Norris the character of the tissue in the abdominal mass made it difficult to discern if it was an enlarged testicle or an abnormality in Bear’s spleen. In either case, it required further exploration. She performed exploratory surgery and found the enlarged testicle. She removed it without complication, and she found no other abnormalities during surgery. She sent the testicle to be tested for cancer, and the results showed it was a benign seminoma, a tumor that is not cancerous. Consequently, removal is expected to be curative in this case.
What causes cryptorchidism?
Though toy breeds, such as Yorkshire Terriers and toy poodles, are at higher risk for cryptorchidism, it occurs in 1.2 percent of all dog breeds. About 75 percent of cryptorchidism cases involve only one retained testicle, and the right is twice as likely to be retained as the left. Genetic factors contribute to cryptorchidism. Environmental factors may contribute as well.
Dogs’ testicles typically descend within two months of age, and rarely after six months.
What are the symptoms of cryptorchidism?
Symptoms of cryptorchidism don’t normally include pain or other clinical signs, unless a complication develops. If both testicles are retained, the dog may be infertile. Otherwise, the only sign of a retained testicle is the absence of a testicle in the scrotal sac reducing its size, or the absence of testicles altogether.
When a dog’s history isn’t entirely known at the time of adoption and no testicles are present in the scrotum, it is reasonably presumed the dog has been neutered. In a small percent of these instances, the dog will be intact and cryptorchid. The dog may show signs of persistent male hormone including aggression, escape behaviors, and increased musculature.
One complication of cryptorchidism is spermatic cord torsion: the twisting of the spermatic cord upon itself. This will lead to sudden and severe abdominal pain. The most common complication, however, is cancer. Cryptorchid dogs are at least 10 times more likely to develop testicular cancer than normal intact dogs. Just over half of all Sertoli cell tumors and one third of all seminomas occur in retained testicles.
How is cryptorchidism treated?
With neutering. Removing the retained testicle(s) is recommended as soon as possible. Cryptorchid dogs will receive two incisions – one for each testicle – unless both testicles are in the abdomen. The surgery is routine and outcomes are overwhelmingly positive.