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Cryptorchidism in Dogs (Undescended Testicles)

Posted May 29, 2015 in Dog Diseases & Conditions A-Z

AJ Debiasse, a technician in Stroudsburg, PA, contributed to this article.

Cryptorchidism occurs when one or both of the testicles are not in the scrotum (or sac). This is also called undescended testicle(s) or retained testicle(s). Although this genetic condition may not seem like a big deal, it is cause for great concern.

When a puppy is born, the testicles reside in the abdomen, near the kidneys. As your pup ages, they slowly migrate to their rightful location in the scrotum. In dogs with this genetic disorder, one (unilateral) or both (bilateral) testicles get hung up somewhere along their journey.

Both testicles should be descended by 2 months of age and should be confirmed by your veterinarian during the first “puppy exam.” Many people believe that the “cut off” age is 6 months but this is a stubborn myth. It is very unlikely that testicles will “descend” after 2 months of age.

Where do the testicles go?
There are 2 main locations for the undescended testicle(s) to end up:

  • In the belly (abdominal cryptorchid)
  • Where the abdomen meets the back legs (called the inguinal region [inguinal cryptorchid])

Depending upon the location, your vet may be able to feel the undescended testicle during a physical exam.

What problems are caused by cryptorchidism?
Leaving a cryptorchid dog intact, i.e. not neutered, can cause severe health problems. One is called testicular torsion, a fairly rare situation. A testicle that is retained in the belly is free floating, instead of being secured in its intended location, so it could suddenly twist on itself. This is a very painful condition, sometimes challenging to diagnose.

It gets worse: cryptorchid dogs have a higher risk of testicular cancer. It is believed that the risk of cancer is related to a higher temperature in the belly compared to the scrotum. Even though the probability of metastasis (or spreading) is low, it is still possible. So leaving your dog intact can be an unnecessary risk.

Preventing cryptorchidism
Since cryptorchidism is a genetic disease, it is not recommended to breed dogs with this condition, as the father could pass it along to his offspring. This is actually assuming the father can reproduce. Most dogs with bilateral cryptorchidism (meaning that both testicles are retained) are sterile. The temperature inside the body is too high and sperm cells are unable to form properly.

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Dr. Phil Zeltzman is a board-certified veterinary surgeon and author. His traveling practice takes him all over Eastern Pennsylvania and Western New Jersey. You can visit his website at, and follow him at