Now You See Them, Now You Don’t

Before birth, the testicles are located near the kidneys. From there, they migrate across the abdominal cavity and descend into the scrotum within two weeks of birth. This occurs in three stages, and problems can happen anywhere in this process. These can be chromosomal, hormonal or physical in origin.

Normal, healthy male puppies should have two normally descended testicles by eight weeks of age. At this age, detection may be difficult, because they are extremely small, especially in the case of toy breeds. It may take up to 16 weeks for the testicles to fully descend in some toy breeds. In rare cases, they have been known to descend as late as 7 months. Prior to the onset of adolescence, they can be easily retracted into the inguinal area.  Between 5-8 months of age, adolescent hormonal surges cause the testicles to undergo a marked size increase. The inguinal ring usually closes by six months of age, which should effectively prevent movement of the testicles in either direction. The timing of these events is also influenced by the size of the dog, occurring earlier in small faster maturing breeds.

Regardless of whether a puppy is destined to become a show prospect or a pet, breeders should get into the habit of checking their puppies for retained testicles. Not only is this helpful for socialization, it is impossible to eradicate a problem like this from a breeding program without accurate records.

It is usually easier to do this if the puppy is lying calmly on its back. In that position, the testicles can be gently massaged into position.

 It may be difficult to locate and examine the testicles of puppies that are apprehensive about this type of handling. It is not unusual for young dogs to pull their testicles up when nervous or cold. However, they should return to their normal position without difficulty.  As they mature, this becomes increasingly difficult and ultimately impossible for normally developed males.  Adults should never exhibit this tendency; both testicles should be of the same size, a firm consistency and remain in place.

Cryptorchidism (hidden testicle) is often referred to as monorchidism. Most often, the right testicle is undescended- unilateral cryptorchidism. If the other testicle is normal, many unilateral cryptorchids are capable of breeding and possess various degrees of fertility. Males with both testicles retained are technically known as bilateral cryptorchids. They are invariably sterile because normal internal body temperature will inhibit sperm production. Retained testicles do however, continue to produce testosterone. Because of all these variable factors, cryptorchidism cannot be definitely diagnosed prior to 6 months of age.

Possible Treatment For Undescended Testicles

If retained testicles can be located and manually manipulated into position, many breeders report success by pulling inguinally retained testicles into the scrotum with gentle downward traction several times a day. Other treatments include surgical placement of the retained testicle in the scrotal sac-orchiopexy. Repositioned testicles usually regain some size and sperm function. Human studies have revealed that repositioned testicles remain at higher risk for cancer regardless of age at time of surgery.

The fact that the problem occurs more frequently in small breeds points to a combination of growth rate, physical size, and hormonal causative factors. Therefore, medical treatment with gonadotropic agents has not been consistently successful. Testosterone injections have not proven to be effective. In some cases, weekly IM administration of human chorionic gonadotrophin for 3-6 weeks has been known to cause testicular descent

True monorchidism –aplasia of one testicle – is extremely rare. If one testicle is present, the other one is invariably in there somewhere although it may be a challenge to find it. Testes may be retained in the prescrotal tissue, the inguinal area, or the abdomen. Inguinal retention is the most common location. Retained testicles are invariable smaller than normal, and this size decrease will correlate with the degree of retention.

Surgical removal of retained testicles is the most commonly recommended treatment. This is understandable considering the hereditary nature of the problem and the associated risks of cancer and torsion of the spermatic cord. Undersized testicles retained in the inguinal area are sometimes difficult to locate, and may be hard to distinguish from lymph nodes or fat deposits. Abdominally retained testicles cannot be detected by palpation unless they become enlarged by tumor development or torsion of the spermatic cord. They can sometimes be located by ultrasound. But their small size and large number of possible locations makes this difficult. Some abdominally retained testicles can only be located by surgical exploration.