Your Puppy Has an Undescended Testicle: What It Means and What to Do

Discovering that your puppy has an undescended testicle can feel alarming, especially if this is your first time navigating the condition. You’re not alone — this is one of the more common reproductive abnormalities seen in male dogs, and the good news is that it’s very manageable with the right veterinary care. Understanding what’s happening inside your puppy’s body, and what steps to take next, will help you feel confident and prepared.

Common Causes

The condition is known medically as cryptorchidism, which simply means one or both testicles have failed to descend into the scrotum as they should. In a healthy male puppy, both testicles typically migrate from the abdomen down into the scrotum by around six to sixteen weeks of age. When that process doesn’t complete on schedule, the testicle may remain somewhere along its migration path — either in the abdomen or in the inguinal canal, which is the passage between the abdomen and the groin.

The exact cause isn’t always clear-cut, but veterinary research points to several contributing factors:

• Genetics and hereditary factors: Cryptorchidism is widely considered to have a strong genetic component, and certain breeds are predisposed, including Chihuahuas, Poodles, Yorkshire Terriers, Boxers, Bulldogs, Dachshunds, and Shetland Sheepdogs.
• Hormonal imbalances: Insufficient levels of hormones that guide testicular descent during fetal development may play a role.
• Abnormal connective tissue: The gubernaculum is a ligament-like structure that guides the testicle downward. If it develops abnormally, the testicle may not follow the correct path.
• Small scrotal size: In some puppies, the physical structure of the scrotum itself may not adequately accommodate descending testicles.
• Unknown developmental factors: In many cases, no single identifiable cause is found, and the condition is simply a variation in normal development.

From a diagnostic standpoint, your veterinarian will usually begin with a thorough physical examination, feeling along the inguinal canal and lower abdomen for the retained testicle. If it can’t be located by touch, an abdominal ultrasound is the most common next step — it allows the vet to pinpoint exactly where the testicle is sitting without invasive procedures. In rare cases where ultrasound results are inconclusive, additional imaging such as MRI may be used, though this is uncommon in everyday practice.

It’s also worth understanding the hormonal side of this condition more deeply. The descent of testicles is orchestrated by a cascade of hormonal signals, including luteinizing hormone (LH) and testosterone, which are active during late fetal development and the first weeks of life. When these signals are insufficient or mistimed, the gubernaculum may fail to contract and shorten properly, leaving the testicle stranded. This hormonal component is one reason why cryptorchidism is considered a developmental condition rather than something that happens due to injury or illness.

Age is a meaningful factor here as well. Most veterinarians take a “watchful waiting” approach in puppies younger than four months, since natural descent can still occur during this window. However, the window does close. If both testicles are not in the scrotum by six months of age, spontaneous descent becomes extremely unlikely, and the conversation should shift toward surgical planning. There is no seasonal pattern associated with cryptorchidism — it is present from birth and tied entirely to development rather than environmental timing.

It’s worth noting that because the condition is hereditary, affected dogs are generally not recommended for breeding, as they can pass the trait on to their offspring.

Symptoms to Watch For

In young puppies, cryptorchidism is often discovered by a veterinarian during a routine wellness exam rather than by a concerned owner at home. That said, knowing what to look for — especially as your puppy gets older — is always helpful.

• An empty or asymmetrical scrotum: One side of the scrotum appears noticeably flatter or smaller than the other, or the scrotum appears completely empty in the case of bilateral cryptorchidism.
• A small lump in the groin area: If the testicle is retained in the inguinal canal, you may be able to feel a soft, small mass near your puppy’s inner thigh or lower abdomen.
• No visible abnormal behavior in puppies: Young puppies with undescended testicles typically show no signs of pain or discomfort, which is why the condition often goes unnoticed without a vet exam.
• Signs of complications in older dogs: Undescended testicles are significantly more likely to develop into testicular torsion or testicular cancer over time. Watch for abdominal pain, swelling, lethargy, vomiting, or changes in behavior in an intact older dog.
• Feminization symptoms in intact adults: A retained testicle may occasionally produce excess estrogen, leading to signs like hair loss, enlarged mammary tissue, or attraction of other male dogs.

The earlier this condition is identified and addressed, the better the long-term outcome for your dog.

Symptom Severity at a Glance

Symptom	Risk Level	Action Required
Asymmetrical or empty-looking scrotum in a young puppy	Mild	Schedule a routine vet appointment within the next week
Palpable lump in the groin or inguinal area	Mild	Mention at next vet visit; monitor for changes
No testicle descended by 6 months of age	Moderate	Call your vet to discuss surgical planning
Hair loss, enlarged mammary tissue, or feminization signs	Moderate	Call your vet within 24–48 hours
Abdominal pain, restlessness, or guarding the belly	Serious	Call your vet promptly — same-day evaluation needed
Sudden vomiting, collapse, or rapidly swelling abdomen	Serious	Seek emergency veterinary care immediately

Breeds Most at Risk

While cryptorchidism can occur in any male dog, certain breeds carry a meaningfully higher genetic predisposition. If your dog falls into one of these groups, early and regular veterinary screening is especially important.

Chihuahuas are among the most frequently affected breeds. This is largely attributed to the high prevalence of the condition within the breed’s gene pool, likely the result of decades of breeding without rigorous screening for reproductive abnormalities. The condition in Chihuahuas is often unilateral, meaning only one testicle is retained.

Toy and Miniature Poodles are also consistently overrepresented in cryptorchidism cases. Researchers believe the genetic mutation responsible for disrupting normal gubernacular development is more prevalent in these lines. Because Poodles are popular and widely bred, the trait has the opportunity to spread broadly across generations.

Boxers show an elevated incidence as well, likely tied to the broader pattern of reproductive anomalies seen in brachycephalic and deep-chested breeds. In Boxers, there may also be an association with other developmental conditions, so a thorough wellness evaluation is always worthwhile in this breed.

If you have a breed known to be predisposed, be proactive about asking your veterinarian to check testicular placement at every puppy visit — don’t wait for them to bring it up.

What You Can Do at Home

If you’ve noticed that one or both of your puppy’s testicles don’t appear to be in the scrotum, the most important first step is to schedule a veterinary appointment as soon as you’re able. There is unfortunately no safe or effective home remedy that will encourage a testicle to descend on its own, and attempting to manipulate the area at home is not recommended.

What you can do at home is observe and document. Make note of whether you can feel a lump in the groin area, whether your puppy seems uncomfortable when touched there, and whether both sides of the scrotum appear symmetrical. This information will be valuable to share with your veterinarian.

If your puppy is already under the care of a vet and the situation is being monitored, continue to attend all scheduled wellness visits. Your vet may recommend waiting until your puppy is a bit older before drawing final conclusions, since some testicles descend later than others — though most veterinarians agree that if a testicle hasn’t descended by six months of age, it is unlikely to do so on its own.

Keeping your puppy at a healthy weight and providing a calm, low-stress environment won’t reverse cryptorchidism, but it will support their overall health as you navigate next steps with your vet.

When to See a Vet

You should schedule a veterinary appointment promptly if you suspect your puppy may have an undescended testicle. This is not an emergency situation in a young puppy, but it is something that should be evaluated and monitored by a professional. Your vet will perform a physical examination and may recommend an ultrasound to locate the retained testicle if it cannot be felt externally.

The standard and strongly recommended treatment for cryptorchidism is surgical removal of the retained testicle, a procedure known as a cryptorchidectomy, which is typically performed at the same time as routine neutering. This is recommended because undescended testicles carry a significantly elevated risk of developing testicular cancer — studies suggest the risk may be up to thirteen times higher than in normally descended testicles. They are also prone to testicular torsion, a painful and potentially life-threatening twisting of the testicle that requires emergency surgery.

Seek immediate veterinary care if your dog shows signs of sudden abdominal pain, vomiting, lethargy, or a rapidly swelling abdomen, as these can indicate torsion or another serious complication.

How Pet Insurance Can Help

Veterinary procedures like cryptorchidectomy, especially when combined with abdominal surgery to locate a retained testicle, can be significantly more costly than a standard neuter. Having a pet insurance policy in place before your puppy needs care can make a real difference in your ability to say yes to the treatment your dog needs without financial stress. Many plans cover surgical procedures and diagnostics, giving you peace of mind from the very start.

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For times when you need immediate guidance from a licensed veterinarian without leaving home, telehealth services can be a lifesaver.

For more clinical details on canine health, you can refer to the professional guidelines from the Merck Veterinary Manual.

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Cryptorchidism is a common condition that, with timely and appropriate veterinary care, carries an excellent prognosis for a long, healthy, happy life. Your attentiveness as a pet parent — noticing something wasn’t quite right and seeking answers — is exactly what your puppy needs. With your vet’s guidance and a clear treatment plan, your pup will be well on their way to thriving.