What Is a Dog Neuter or Castration?

eight month old puppy with a cone on his neck protecting him from licking the area where he was neutered
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"Neuter" is a common term for castration in a dog. It is the surgical removal of a male dog's testicles. A neuter must be performed under general anesthesia by a licensed veterinarian. A neuter is sometimes referred to as getting the dog "fixed."

Why Do Dogs Get Neutered?

Dogs are typically neutered in order to eliminate the possibility of reproduction. A secondary reason for neutering is to avoid certain things associated with male hormones.

Hormone-related behaviors like marking and humping may be prevented or decreased by neutering. The neuter is often performed on puppies around the age of six months (sometimes earlier) before the dog reaches sexual maturity (puberty, basically). Neutering significantly reduces the risk of prostate cancer and various testicular diseases in male dogs. In some cases, a dog must be neutered in order to treat a medical condition related to the testicles. 

What Are the Risks of a Neuter?

While a neuter is often considered to be a routine surgery, the procedure is not without risk. As with any surgical procedure, risks include anesthesia reaction, excessive bleeding, bruising, and infection. Fortunately, complications during neuters are uncommon.

It's important for a veterinarian to thoroughly examine the dog and perform lab work prior to surgery. These can enable the vet to detect health issues that increase the risk of complications during and after surgery.


Overall, the prognosis for a full recovery is excellent in healthy dogs. 

What Happens During a Neuter?

Prior to surgery, the dog is put under general anesthesia. This typically involves drug to induce anesthesia that is injected through an intravenous catheter. Pain medication may be started in advance.

Next, a breathing tube is placed in the dog's trachea to maintain an open airway and deliver oxygen mixed with gas anesthesia. The gas percentage is adjusted to maintain the optimum anesthesia level.

Once the dog is under anesthesia, monitors are typically set up and technicians measures to keep the dog warm (because body temperature drops during anesthesia). Intravenous fluids may be administered to maintain blood pressure, prevent dehydration, and offset blood loss during surgery. Vital signs are monitored to make sure the dog is safe during the procedure.

Next, the anesthetized dog is placed on his back. A technician shaves the hair above the scrotum (below the penis) and scrubs the skin with a special surgical cleanser that removes dirt and germs. Meanwhile, the veterinarian "scrubs in" with surgical cleanser, then puts on a sterile surgery gown and sterile gloves. To prevent the spread of germs, all staff members in the operating room wear caps to cover their hair and masks to cover their mouths and noses.

Before making the first cut, the veterinarian covers the dog with sterile drapes to keep germs and debris from getting into the surgery site. Then, a scalpel is used to make a small incision through the layers of skin and tissue between the scrotum and the penis.

Using special surgical instruments, the vet locates the testicular blood supply and sperm ducts, then skillfully ties them off with suture before the carefully cutting away the testicles. The incision is then closed with many layers of internal sutures. Some vets use special skin glue to close the outer layer of skin while others still use visible external sutures (this is a matter of that vet's preference and the dog's specific needs).

After the surgery is complete, a technician will clean the incision gently and move the dog to recovery. Additional pain medication may be given depending on the dog's needs. The goal is for the dog to wake up in a soft, warm bed with as little pain as possible. 

In general, the full process around the neuter will last about 30-60 minutes (from the time anesthesia starts until the dog is awake).

The neuter surgery itself typically takes about 10-20 minutes. 

Recovery from Neuter Surgery in Dogs

Most dogs begin to recover quickly after surgery. However, it is important for your dog's activity to be restricted for a week or two after surgery. This allows the surgery site to heal properly. Running and jumping can cause internal stitches to tear or result in other inflammation that hinders healing. In addition, it's important to keep your dog from licking at the incision. Licking will cause irritation and introduce bacteria to the incision, both of which can lead to infection. For this reason, many vets recommend using an e-collar after surgery. This is the conical collar jokingly called the "cone of shame."

More Neuter Info

Pronunciation: NOO-ter (rhymes with "tutor")

Also Known As: Castration, sterilization

Common Misspellings: nueter


  • My dog had no complications during his neuter.
  • Most male puppies are neutered at six months of age.
  • Will you have the vet neuter your dog, or will you keep him intact?