Cryptorchidism in Dogs: Causes, Risks & Treatment

When male puppies are born, their testicles are located inside the abdomen near the kidneys. Normally, over the first 1 to 2 months, these testicles descend through the inguinal canal into the scrotum outside the body. Sometimes this process may complete up to 4 to 6 months of age and still be considered within normal limits.

Cryptorchidism occurs when one or both testicles fail to descend properly and remain retained within the dog's body either in the abdomen or the inguinal canal. This condition is hereditary and results from the improper development of the connective tissue guiding the testicular descent.

Why is cryptorchidism a problem in dogs?

Cryptorchidism presents several health concerns. Retained testicles still produce testosterone but usually do not produce sperm, leading to infertility if both testicles are undescended. More importantly, retained testicles significantly increase the risk of developing testicular cancer—about 13 times more than in dogs with normally descended testicles. Additionally, serious complications like testicular torsion, where the spermatic cord twists cutting off blood supply, can cause severe abdominal pain and require emergency care.

Because of these risks, veterinarians recommend surgical removal of retained testicles, especially if they have not descended by 6 months of age. This surgery prevents potential cancer and other complications while also eliminating the chance of the dog passing on this genetic condition to offspring.

Which dogs are more likely to have cryptorchidism?

Cryptorchidism can affect any male dog, but it is more common in some breeds, especially toy and miniature dogs such as poodles, pomeranians, and Yorkshire terriers. Breeds like Staffordshire Bull Terriers, German Shepherds, and Boxers also show a higher incidence of this condition. Interestingly, the right testicle is more often the one retained than the left.

Around 1% to 15% of male dogs are affected, with purebred dogs more often impacted than mixed breeds. Genetic inheritance is considered the primary cause, with cryptorchidism typically passed as a recessive trait.

Recognising symptoms of cryptorchidism

By about six months of age, it is usually evident if a dog is cryptorchid as one or both testicles will be missing from the scrotum. The condition is generally painless, but in rare cases, testicular torsion can cause sudden severe abdominal pain. Tumours in retained testicles are more common and can cause increased production of oestrogen, leading to feminised behaviour and attraction of intact male dogs.

How is cryptorchidism diagnosed?

Your vet will perform a physical examination to locate the descended and possibly retained testicle. If not palpable in the inguinal canal, ultrasound imaging is used to locate testicles retained deeper within the abdomen accurately.

What does treatment involve?

The treatment of choice is surgical castration to remove both the normally descended and the retained testicle(s). It is neither viable nor ethical to attempt to reposition an undescended testicle without neutering, as this leaves health risks and the potential to pass on the genetic condition.

Prompt surgical intervention protects your dog's health by preventing testicular cancer and other complications, and it helps control the spread of cryptorchidism through breeding.

Responsible breeding and ownership

Because cryptorchidism is hereditary, responsible breeders avoid breeding dogs with the condition to reduce its incidence in the wider dog population. If you are looking for a puppy, seek out reputable breeders who screen for hereditary conditions and provide health guarantees.

Early veterinary checks and neutering are vital parts of good pet care, ensuring your dog's well-being and helping prevent future health problems.

Summary of cryptorchidism in dogs