What is Cryptorchidism?

Cryptorchidism is a condition in male dogs where one or both testicles fail to descend into the scrotum by the time the puppy is around six months old. Normally, the testicles descend from the abdomen through the inguinal canal into the scrotum shortly after birth. When this doesn’t happen, the testicle(s) may remain:

• Inguinal (groin) region: Just under the skin near the inside of the hind leg
• Abdominal cavity: Deep within the abdomen, where it cannot be felt on physical examination

Causes of Cryptorchidism

Cryptorchidism is primarily a genetic condition, meaning it is inherited from one or both parents. It is more common in small and toy breeds such as Chihuahuas, Pomeranians, Yorkshire Terriers, and Miniature Poodles, though it can occur in any breed. Environmental or developmental issues in utero may also contribute in some cases.

Because the condition is inherited, affected dogs should not be bred, even if only one testicle is retained.

Complications of Cryptorchidism

• Increased risk of testicular cancer - Retained testicles are at significantly higher risk of developing testicular tumours, particularly Sertoli cell tumours and seminomas. Dogs with abdominal cryptorchidism are up to 13 times more likely to develop testicular cancer than dogs with normally descended testicles.

• Risk of torsion (twisting) - A retained testicle, especially in the abdomen, is prone to twisting (testicular torsion), which is a painful emergency requiring surgery.
• Behavioural issues - Dogs with retained testicles may still produce testosterone, which can lead to unwanted behaviours such as aggression, mounting, urine marking, or roaming.

Treatment Options

The only effective treatment for cryptorchidism is surgical removal (desexing). This includes removing both the retained and descended testicle (if present), as leaving the retained testicle behind is dangerous and does not eliminate cancer risk or hormonal effects.

• Abdominal cryptorchidism: This requires an exploratory surgery under general anaesthesia. A small incision is made in the abdomen to locate and remove the retained testicle.
• Inguinal cryptorchidism: The testicle may be located just under the skin and removed through a smaller incision.

Important Notes:

Retained testicles do not descend later in life. If one or both testicles are not in the scrotum by 6 months of age, they are considered cryptorchid.

Castration of cryptorchid dogs is also necessary to prevent them from passing this inherited condition on to their offspring.

Post-Surgical Outlook

Most dogs recover quickly from cryptorchid surgery, especially when the condition is detected early and treated before complications occur. Your veterinarian will advise you on aftercare and follow-up.