| | | | | | | | | | | |

A Tales of Two Testes

By Kim Everson, DVM

Pancho* is a cheerful, bright little chihuahua with a very big problem: neither of his testicles ever descended into his scrotum. For most of his life, little Pancho appeared physically just like a neutered dog with nothing between his legs. And in practical terms, he was similarly sterile because the heat of his body made it impossible for any sperm to survive. These two facts – appearance and sterility – don’t seem like terribly big problems, but they can be life threatening.

A few years ago, when he was about 8 years old, Pancho’s left testicle suddenly became noticeable. In his left groin, he developed a firm lemon-sized swelling. It wasn’t painful and didn’t seem to bother him in any way. When I first saw Pancho for an examination a couple months ago, his family expressed a desire to neuter him because of the concern his testicle might continue to enlarge and negatively affect his quality of life.

We discussed the numerous scenarios I might encounter during Pancho’s cryptorchid neuter. Cryptorchid literally means “hidden testicle” and it is the most common reproductive disorder of male dogs. Normally, the testicles descend into the scrotum within days of birth although the descent may be delayed up through puberty in some dogs. In a cryptorchid male, one or both of the testes fail to “drop” into the scrotum. The “hidden testicle(s)” could be anywhere ranging from just in front of the scrotum under the skin, trapped in the inguinal canal (the oblique opening in the abdominal wall through which the testes should descend), or stuck inside the abdomen. In Pancho’s case, we felt pretty confident that the palpable swelling in his left groin was one testicle (although we couldn’t rule out it being a tumor of some kind) but the right testicle could not be readily identified. We discussed how it may still be inside the abdomen making his neuter surgery more like a female dog’s spay surgery.

Retained testicles are associated with all sorts of weird problems.

  1. The trait to retain one or both testicles is hereditary, which seems counter-intuitive because I already mentioned cryptorchid dogs are sterile! Some dogs, however, have normal scrotal descent of one testicle which is fully functional. Nature often gives us two organs for a reason — the redundancy is a back-up! A unilaterally cryptorchid male dog can successfully reproduce but he should not be intentionally bred. As we’ll see, it is not in the best interest of his future puppies to be affected by or carry the trait for cryptorchidism. Regretfully, in fact,  cryptorchidism occurs disproportionately more often in Toy and Miniature Poodles, Pomeranians, Dachshunds, Chihuahuas, Maltese, Boxers, Pekingese, English Bulldogs, Miniature Schnauzers, and Shetland Sheepdogs due to its hereditary nature. Incidentally, dogs that have delayed testicular descent (meaning later than 8 weeks old according to some sources) should not be bred either, because the delay is considered a milder form of cryptorchidism and can be inherited by future puppies.
  2. Although the retained testicle is sterile because the dog’s core body heat impairs sperm production, the cryptorchid testicles does still produce testosterone. Cryptorchid male dogs may demonstrate negative social or behavioral effects of testosterone including mating behavior, aggression, increased urine marking, wandering in search of a mate, etc.
  3. Life threatening diseases are commonly associated with cryptorchidism, which is the number one reason why this trait should be eliminated from breeding stock and why cryptorchid males should be fully neutered as soon as practical. One potential health problem, particularly seen with abdominal testicles, is testicular torsion. Torsion is rather rare, but it is extremely painful and dangerous. Basically, the testicle twists around on the spermatic cord cutting off its own blood flow. The affected testicle can become necrotic (or gangrenous) leading to sepsis, shock and death. Emergency surgery and intensive care are required to treat a testicular torsion. The most common and most insidious health concern related to cryptorchidism is cancer. There are many different types of testicular cancer, but the most common form of cancer in cryptorchid cases is Sertoli Cell Tumor. Seminoma and Leydig cell tumors occur with high frequency as well. Up to 40% of dogs with testicular cancer have more than one type of tumor present! 
Pancho’s cryptorchid testicles are both dramatically abnormal with one being tiny and the other being quite large and misshapen.

On the day of Pancho’s surgery, we clipped and prepped for the possibility of entering his abdominal cavity to retrieve one or both testicles; although when Pancho was finally anesthetized I thought I might be able to feel his right testicle under the skin in his groin. First I decided to tackle the large swelling in his left groin, what I suspected and hoped was his left testicle. Just as in a routine canine neuter, I made a single incision in front of the scrotum, but in this case I made it large enough to accommodate a very large testicle.

Turns out Pancho has quite a bit of paunch! It took a lot of blunt dissection through a thick layer of subcutaneous fat and also a great deal of care to not accidentally cut any of the large mammary blood vessels in the vicinity of the swelling. Finally, I identified the unmistakable shiny layer of tissue that surrounds the testicle and spermatic cord confirming it was indeed an enormous testicle and not some other kind of mass. With some coaxing, I was able to exteriorize the testicle, clamp the cord and amputate the teste as usual. What was not usual was the appearance of the left testicle. Rather than being a smooth, bean-shaped organ, Pancho’s left testicle was large, lumpy and irregular looking. My scientific curiosity only heightened, it was time to proceed to the right testicle!

Close up view of Pancho’s tiny right testicle and misshapen left testicle.

Again I gently palpated Pancho’s right groin area. Deep under the fat I localized a firm, movable, oval swelling. Was it the testicle? Or was it just an accumulation of fat? Because I already had made a midline incision, I decided to explore the area through this opening before committing to an abdominal incision. As before, it took some patience and care to work down through the fat and vessels, but I was eventually rewarded by the sheen of the spermatic cord fascia. I had found the second testicle! This teste was remarkably small and soft compared to a normal adult canine teste. As before, I finished amputating the teste from the spermatic cord, then proceeded to close the subcutaneous and skin layers with absorbable suture. Because of Pancho’s history of cryptorchidism, I placed a permanent tattoo mark near the incision to show any future veterinarian that Pancho was indeed fully neutered and no longer bilaterally cryptorchid.

As my certified veterinary technician administered perioperative pain medications, cleaned up Pancho’s skin and gently woke him up from anesthesia, I evaluated the two testicles further. Neither teste was what I would consider normal for size, shape or texture. Just as Pancho’s left teste was enormous, hard and misshapen, his right teste was tiny and very soft. I could not determine whether the right testicle was underdeveloped due to its aberrant location, or whether it had atrophied under the “bullying” influence of the over-exuberant left testicle.

Next I cut each teste longitudinally to evaluate the parenchyma, or functional tissue inside. The appearance of the parenchyma was surprising. The tissue of the right testicle was uniform, squishy and smooth. The inside of the large left testicle was firm and irregular with nodules bulging from the cut surface. It looked like the majority of the testicle had been replaced by some kind of cancerous growth.

Cross section of the right and left testes: the left testicle parenchyma has been obliterated by tumorous growth.

In order to get a definitive diagnosis for Pancho, we sent the testicles to the lab for histopathology testing. Histopathology involves slicing the tissue into thin slivers which are specially stained and fixed to glass slides for microscopic evaluation. After several days of anxious waiting, Pancho’s test results returned with some surprising news. While his left testicle indeed was nearly obliterated by Sertoli Cell cancer, both it and the tiny right testicle also had seminoma tumor present! The good news, however, is that the tumor cells were completely contained within the testicular capsule. The risk of these cancers spreading to other parts of the body, like the lungs, liver, or lymph nodes, is low. Fortunately, Pancho’s prognosis for a full recovery is excellent!

Testicular cancer is at least 10 times more likely to develop in cryptorchid testicles than in normally placed scrotal testicles. Moreover, testicular cancer develops at a younger age (less than 10 years old) in cryptorchid dogs. While neutering a cryptorchid dog is a more invasive procedure, the risk, recovery time and cost is typically similar to that for a canine spay. When you weigh these cons against the huge protective benefits of neutering a cryptorchid dog, I definitely feel it is worth doing the neuter. For Pancho, shedding his testicles probably just added years to his happy little life!

*Name has been changed to protect privacy of the family.

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *