Post-neutering swelling is the most common reason a dog looks like he still has testicles after the procedure. The scrotum, which is the skin pouch that held the testicles, is almost always left in place during a standard neuter. Without the testicles inside, it fills with fluid and swells, sometimes looking nearly identical to how it did before surgery. In most cases this is completely normal and resolves on its own.
That said, there are a few other explanations worth knowing about, some routine and some that warrant a call to your vet.
The Scrotum Stays After Surgery
This is the detail that surprises most dog owners: neutering removes the testicles, not the scrotal sac. During a standard canine neuter (called an orchiectomy), the veterinarian makes an incision, removes both testicles, ties off the blood supply and spermatic cord, and closes the incision. The empty scrotal skin is left behind. In the days after surgery, that empty pouch swells with fluid as part of the normal inflammatory healing response, and it can look remarkably like your dog was never neutered at all.
Some veterinary clinics do perform what’s called a scrotal ablation, where the scrotal skin is removed along with the testicles. This is more common in older or larger dogs whose scrotal tissue is loose enough that leaving it could cause long-term drooping or irritation. But for most dogs, especially younger ones, leaving the scrotum intact is standard practice and leads to fewer complications.
Normal Swelling vs. a Problem
Mild swelling and redness at the surgery site should resolve within several days. Male dogs may also have small amounts of drainage or discharge for up to three days after the procedure. Any bumps or bruises that develop should gradually decrease in size over the recovery period, which typically spans 10 to 14 days.
The swelling can look alarming, especially in larger breeds where the scrotum was already prominent. Some dogs develop enough post-surgical puffiness that the area looks the same size it was before, or even slightly larger. This is particularly common when the traditional prescrotal incision technique is used, which carries a higher risk of scrotal swelling and fluid accumulation (called a hematoma) compared to newer scrotal incision approaches.
What’s not normal: swelling that keeps getting bigger after the first few days, a scrotum that feels hot to the touch, discharge that’s thick or foul-smelling, or signs that your dog is in increasing pain. These could indicate a hematoma, infection, or a problem with the incision site. The most common complications after neutering are hemorrhage, pain, swelling, and the incision opening up, so keeping your dog calm and preventing him from licking the area is critical during recovery.
Could a Testicle Have Been Missed?
This is rare but not impossible, and it’s more likely in dogs with a condition called cryptorchidism, where one or both testicles never descended into the scrotum. In cryptorchid dogs, the undescended testicle may be sitting in the abdomen or the inguinal canal (the passageway between the abdomen and the scrotum), making it harder to locate and remove.
A study in the Journal of the American Veterinary Medical Association found that the most common serious complications during cryptorchid castrations involved not identifying the retained testicle correctly. In some cases, the abnormal appearance of the undescended testicle, which can be smaller, misshapen, and similar-looking to surrounding tissue, led to confusion during surgery. If your dog was known to have an undescended testicle before the procedure, it’s worth confirming with your vet that both testicles were successfully removed.
For dogs with two normally descended testicles, a missed testicle is extremely unlikely. Your vet can confirm removal with a simple physical exam or, if there’s any doubt, a blood test measuring testosterone levels a few weeks after surgery.
Testicular Implants
If you adopted or rescued a dog that was neutered before you got him, there’s another possibility: testicular implants. A product called Neuticles has been on the market since 1995. These are prosthetic testicles made from a rigid material that are placed inside the scrotum during the neuter surgery to preserve the dog’s natural appearance. They feel firmer than real testicles, almost like hard plastic. If your dog’s “testicles” feel unusually solid and uniform, implants could be the explanation. Your vet can confirm this with a quick physical exam.
Vasectomy Instead of Neutering
Another scenario, again most relevant if someone else had the procedure done: your dog may have had a vasectomy rather than a traditional neuter. A vasectomy cuts a portion of the spermatic cord but leaves both testicles completely intact in the scrotum. The dog is sterile but still produces testosterone, still has fully functional testicles, and looks exactly the same as an intact male. Some owners choose this option to prevent reproduction while preserving hormone levels. If you’re unsure which procedure your dog had, your vet can check testosterone levels to determine whether the testicles are still producing hormones.
What to Expect as Healing Progresses
If your dog was recently neutered with a standard castration and you’re seeing what looks like testicles, the most likely timeline is straightforward. Swelling peaks in the first few days, then gradually decreases over one to two weeks. In younger dogs, the empty scrotum often shrinks significantly and becomes barely noticeable within a month or two. In older dogs or larger breeds, the scrotum may remain as a visible flap of loose skin permanently, though it will be flat and soft rather than full.
During recovery, keep the cone or recovery collar on to prevent licking, limit activity to short leash walks, and check the incision site daily. If the swelling hasn’t started to decrease noticeably by day five or six, or if it’s getting worse at any point, contact your vet’s office. Most of the time, though, what you’re seeing is a normal part of healing that will resolve without any intervention.