During physical exam of young male puppies, a veterinarian will examine closely to determine whether both testicles have descended into the scrotum. Testicles will usually descend into the scrotum within a few days of birth, but in some puppies this may be delayed for up to 6 months. Usually if the testicles do not descend by 6 months of age, they usually will not in the future.
The most common presentation is when one testicle does not descend, a condition known as cryptorchidism. The undescended testicle is typically found outside the scrotum, either up in the abdomen, or in the inguinal canal, where it may be palpated by the veterinarian. Veterinarians will monitor the situation closely, because if left untreated, undescended testicles have a more likely risk of developing tumors later on in life. The undescended testicles are also more likely to twist inside the abdomen (known as a torsion), which may lead to loss of blood supply, secondary infection and even death. Treatment is usually early surgical neutering after 6 months of age, in order to avoid these potential serious complications.