When a Testicle Doesn’t Descend

A testicle that does not reach the scrotum is at risk for cancer later in life.


With reports coming out that neutering a male dog as a puppy can increase his risk for certain cancers, some people are opting to leave their male pets intact for a couple of years — or longer. But in up to 3 percent of cases, a dog’s testicle remains undescended, and that in itself raises the risk for a type of testicular cancer called a Sertoli cell tumor.

Consider that during fetal development, a male dog’s testicles start out in about the same vicinity as a female dog’s ovaries and then make their way down into the scrotum, where they remain cooler than they would inside the body — all to the good for healthy sperm. But if one testicle doesn’t descend, it usually remains in the abdomen, somewhere in the back near the bladder (although sometimes under the skin next to the penis). The condition, whether it’s one or both testicles failing to descend, is called cryptorchidism.

The wrong environment inside the body helps set the stage for the tumor. It’s not usually lethal; it doesn’t metastasize. “But it has a tendency to produce estrogen,” explains Your Dog editor-in-chief John Berg, DVM. “Because that’s not normal in a male dog, it can lead to a variety of ill effects, including mammary development, hair loss, and other untoward signs.”

Diagnosis and treatment

The scrotum of any dog who is not neutered should be palpated by a veterinarian to make sure both testicles have descended, Dr. Berg says. If one has not, it should be removed surgically — as long as the dog is at least 6 months old. The testicles typically descend 30 to 40 days after birth but sometimes take as long as 6 months to migrate to the scrotum. Descent time varies by breed. (Once in a while, both testicles fail to descend, and both should be removed as long as the dog is at least 6 months old.) Many veterinarians who are not surgeons feel comfortable performing the procedure, and if they’re not, they can always refer you to a veterinary surgeon who is board-certified.

“It’s a pretty simple operation,” comments Dr. Berg, a surgeon himself — “no more complicated than spaying a female dog. I always do an ultrasound first so I know exactly where the testicle is and don’t have to prolong the anesthesia while searching for it; sometimes it’s ‘hiding’ under the skin next to the penis. The whole operation takes about a half hour.”

While recuperating, the dog has to be walked on a leash for two weeks with no off-leash romping. Afterwards, he’s good to go, with no lingering effects.


Please enter your comment!
Please enter your name here