What Is Cryptorchidism?

Cryptorchidism is a condition in which one or both testicles of your pet fail to descend into the scrotum. It is a very common problem in dogs and cats. It is seen most commonly in purebred animals.

I see about three dogs with this problem for every cat. This is probably because so many ordinary family cats have a rich genetic pool.

We know the problem is genetic because it runs in families or lines. I see it allot in miniature schnauzers, cocker spaniels, chihuahuas and persian cats. But any breed can be affected.

Dog and cats in which both testicles fail to descend are usually sterile. When testicles remain in the pet's abdomen the 4-5 degree higher temperature there prevents the production of sperm. It does not, however, affect the production of testosterone, so these pets exhibit typical male behavior. When one testicle does descend into the scrotum the pet will be fertile. When two missing testicle are under the skin near the scrotum, the pet may be fertile. But it is a very bad idea to breed dogs and cats that are cryptorchid because their descendants will carry the same defective genes.

Sertoli Cell Tumors:

Cryptorchid dogs and cats have a higher rate of developing a certain cancer call a Sertoli cell tumor. The Sertoli cells, which are located in the testicles, provide nourishment to the sperm cells. They also produce feminizing hormones (estrogens). These tumors often cause thin skin, sparse hair coat, aplastic anemia, enlarged breasts and attractiveness to other male dogs. The hair loss in these cases is very specific in that it is identical on both sides of the pet's body (bilaterally symmetrical). Occasionally we may need to do ultrasound examination of the retained testicle as well as a plasma estrogen level to confirm the diagnosis.

Ten to twenty percent of these tumors are malignant and can metastasize (move) to other parts of the body. If the tumor has spread it can be treated successfully with chemotherapy. To avoid this debilitating treatment, veterinarians suggest that the cryptorchid testicle be located and removed before it has the opportunity to becoming cancerous. Another problem that occurs in rare instances in cryptorchid pets is torsion (twisting) of the spermatic cord , the sperm duct that attached to the testicle.

What Are The Signs Of Cryptorcidism?

Cryptorchidism in dogs over twelve weeks of age is easy to see if the scrotal area of your pet is examines. It is a bit harder to see in cats. One only needs to pass the scrotum through pinched fingers to notice that only one or none of the testicles are present. The younger the pet, the smaller the testicles will be. So examination of small puppies and kittens has to be thorough.

In more than half of the cases, I can palpate the missing testicle just forward of the scrotum or in the fat located in the animals groin. In these case, testicles have been relocated into the scrotum. Rarely, testosterone therapy has also allowed the retained testicle to descend into the scrotum.

I do not feel that either of these procedures should ever be done. Doing so, or breeding a cryptorchid pet perpetuates the disease to future generations of dogs and cats. Instead, have your pet neutered so that both testicles are removed.

A special problem comes up when an adult dog or cat that appears to be castrated still exhibits male behavior. Here, we can be uncertain if we are dealing with a castrated dog or a cryptorchid dog, vaginitis or a hormone imbalance so more tests need to be done. Sometimes the retained testicle can be visualized in the abdomen with ultrasound. When this is not the case, the pet can be given an injection of chorionic gonadotropin. If this hormone causes a rise in serum testosterone level one hour after injection we are dealing with a cryptorchid pet. When this question occurs in a cat, we can examine the penis for spines. Spines are much smaller in castrated cats than in cats that still have their testicles – cryptorchid or not.

Testicles migrate from the abdomen to to the scrotum through two small holes in the groin called the inguinal rings. When the missing testicle or testicles have not passed through the inguinal rings and are still located in the abdomen, the surgery is much more complicated.

In effect, you must neuter and spay the same animal. The missing testicle can be anywhere between the rear pole of the kidney and the inguinal ring and it can be nerve racking to find and remove it - particularly if the pet is over weight. These testicles are much smaller and softer than the descended ones and are extremely difficult to locate in the fat that occupies the posterior abdominal space. What usually allows me to find them is the epididymus or sperm collecting tubules that retain their distinctive appearance and feel.

Dogs and cats that are cryptorchid have a higher incidence of other genetic defects such as inguinal and umbilical hernias, abnormally formed penises and sheaths, as well as patellar luxations (trick knees).

Some authorities suggest waiting up to six months before deciding that the testicle(s) are not going to descend. I have never seen a case where the testicle(s) were not descended at twelve weeks of age but descended later. Surgery is always easier on a pet when it is young so do not put off the surgery too long.