How Old Is a Puppy When Their Balls Drop?

When a male puppy is born, his testicles are near his inguinal ring. By the time he's a week to 10 days old, they should descend into the scrotal pouch. An animal's body is too hot for sperm production, so the testicles must descend outside to become fertile. The scrotum, behind the penis, is the right temperature for sperm. Most of the scrotum is actually continuous with the puppy's abdominal cavity.

If one or both of his testicles haven't dropped by the age of 2 months, your puppy is probably cryptorchid, which simply means he has undescended testicles. This condition is hereditary in certain breeds, especially small dogs. According to PetMD, the right testicle is twice as likely not to descend as the left one. The retained testicle might stay in the puppy's inguinal canal. If that's the case, your vet can feel it during an examination. She'll also perform an ultrasound to find its exact location.

Your puppy requires surgery to remove the undescended testicle. Since there's always a chance the testicle will descend by the time the dog reaches the age of 6 months, your vet might schedule the surgery after that date. She will also remove the other testicle, so your dog is neutered. Even if you planned to breed your dog, cryptorchidism is considered a genetic fault so it shouldn't be passed on. Standard neuter surgeries are fairly straightforward, but cryptorchid surgeries are somewhat more complicated. With traditional surgeries, your vet makes a large incision in the abdomen to find and remove the testicle. It's possible to perform this surgery laparoscopically, with just small incisions required. If your vet doesn't perform laparoscopic surgeries, she can recommend a surgeon for your pet.

Without the surgery, your dog is at much greater risk for testicular tumors. According to Michigan Veterinary Specialists, male dogs whose testicles have not descended are much more likely to develop tumors than dogs with normal testicles. Generally, only about 20 percent of tumors have metastasized, or spread, when the cancer is diagnosed, so the prognosis is often favorable. However, the dog must undergo abdominal surgery and possibly chemotherapy and radiation.