Cryptorchidism

Cryptorchidism, also known as cryptorchidism, refers to the condition in which one or both testicles of a dog do not descend into the scrotum. Instead, the testicle remains in the abdominal cavity or the inguinal canal. Normally, a puppy’s testicles migrate from the abdominal cavity into the scrotum shortly after birth. If this does not happen by the age of six months, it is referred to as cryptorchidism.

Forms of cryptorchidism in dogs

• Unilateral cryptorchidism: Only one testicle is affected, the other lies correctly in the scrotum. This is the most common form.
• Bilateral cryptorchidism: Both testes remain in the abdominal cavity or in the inguinal canal. This form is less common and can lead to infertility.

Causes of cryptorchidism in dogs

Cryptorchidism is usually genetically determined and occurs more frequently in certain dog breeds. The cause is considered to be a hereditary disorder of testicular descent. Some breeds are more susceptible to this condition, including:

• Chihuahua
• Boxer
• Maltese
• Poodle
• Yorkshire Terrier
• Dachshund

In addition to genetic predisposition, other factors may play a role:

• Hormonal disorders: Hormonal imbalances during puppy development can influence testicular descent.
• Birth complications: Traumatic births or developmental disorders in the womb are also considered possible influencing factors.

Symptoms of cryptorchidism in dogs

The most noticeable feature of cryptorchidism is the absence of one or both testes in the scrotum. Other signs may be more subtle, but in some cases, significant health problems can arise:

• Missing or only one testis in the scrotum: The scrotum is empty or only one testis is palpable.
• Behavioural changes: Cryptorchidism can affect hormonal balance, which may manifest as increased aggression or restlessness.
• Swelling or pain: If the testis is trapped in the inguinal canal, pain or swelling may occur in this area.

Risks and complications of cryptorchidism

Cryptorchidism is not just a cosmetic problem; it can have serious health consequences:

• Testicular tumours: Dogs with cryptorchidism have a significantly increased risk of testicular cancer, especially if the testis remains in the abdominal cavity. The higher body temperature there promotes malignant changes in the tissue.
• Testicular torsion: A non-descended testis can twist around its own axis. This leads to a painful, potentially life-threatening situation that requires immediate surgical intervention.
• Infertility: In bilateral cryptorchidism, the dog is often infertile because the testes do not reach the correct temperature for sperm production.
• Behavioural problems: If the testis is still functional, hormonal imbalances can influence the dog’s behaviour.

Diagnosis of cryptorchidism in dogs

The vet usually makes the diagnosis through a physical examination: they palpate the scrotum and check whether one or both testes are missing. If the non-descended testis cannot be located this way, further procedures are used:

• Ultrasound: This can locate the testis if it is in the abdominal cavity or in the inguinal canal.
• Hormonal tests: A hormone level test can clarify whether the testis is still functional and producing hormones.
• X-ray: In rare cases, an X-ray helps in locating the testis.

Treatment of cryptorchidism in dogs

Medication cannot correct cryptorchidism. The standard treatment is the surgical removal of the non-descended testis, primarily to reduce the risk of testicular cancer and other complications.

• Castration: The most common and recommended treatment is castration. Both testes are surgically removed to minimise health risks. This also applies to the correctly descended testis, as dogs with genetic cryptorchidism should not be used for breeding.
• Surgical removal of the non-descended testis: If only one testis is affected, it can be removed through an abdominal operation or an incision in the groin area.
• Hormone therapy: In very young puppies, hormone therapy is occasionally attempted to stimulate testicular descent. However, success is uncertain, and due to the genetic background, this approach is often not recommended.

Prevention of cryptorchidism in dogs

Since cryptorchidism is genetically determined, the most important preventive measure is not to use affected dogs for breeding. Responsible breeders test their breeding stock for cryptorchidism so that this predisposition is not passed on to future generations.