Dog Spay vs. Neuter: Age Guidelines, Benefits and Costs

Many dog owners struggle with the question of whether to spay or neuter their pets. Unless you're a responsible breeder or show dogs, usually it's best to have them “fixed" to prevent unwanted puppies and for a whole host of health reasons. But what's the best age for a dog to undergo these procedures? That's a question that has come under debate for pet owners in recent years. Below, we dive into when is the best age to spay or neuter your pup, and why.

Spay vs. Neuter: What's the Difference?

Both terms refer to the removal of a pet's reproductive organs. Although sometimes used interchangeably, they each refer to a different surgical procedure. The best way to keep it straight is to remember that only females can be spayed, while only males can be neutered. So what does “spayed" mean? And what does “neutering" mean?

• Spaying is the removal of a female's uterus and ovaries.
• Neutering is the removal of a male's testicles and associated structures.

While both procedures remove a pet's ability to reproduce and prevent unwanted puppies, each procedure may impact your male or female dog's behavior and overall health in different ways.

Benefits of Spaying or Neutering Your Dog

Spaying or neutering your dog offers a number of benefits that may lead to a longer, healthier life.

Benefits of spaying a dog

In female dogs, spaying is the only known way to prevent pyometra, an infection of the uterus that is extremely serious and could be fatal if not quickly treated. Surgical removal of an infected uterus is also far more dangerous and expensive than having your dog spayed while her uterus is healthy. Spaying also reduces the risk of your pet developing mammary cancer, which has a 50% survival rate and a very short survival time.

If you've ever experienced a dog in heat, then you already know it can be a trying time for both you and your dog. Warding off unwanted attention from male dogs, bloody vaginal discharge, unpleasant odor, erratic and aggressive behavior and constant whining and crying can all be prevented by spaying your dog.

Benefits of neutering a dog

Neutering your male dog eliminates any chances of testicular cancer and decreases the chances of other health issues relating to the prostate. Neutering also reduces problematic behaviors in male dogs, like inappropriate marking and aggression toward other male dogs. It will also reduce the likelihood that your dog will try to escape and run away to find a girlfriend, a behavior that can be dangerous both for him and for other dogs, especially if he's prone to fighting.

What's the Best Age to Spay or Neuter a Dog?

When are dogs typically neutered? For decades, veterinarians have encouraged pet owners to have their puppies neutered or spayed by six months of age, and sometimes as early as four months. But more recent research has discovered that early spay or neuter might not be the best thing for your dog's health. Despite some of the health benefits of spaying or neutering your pup early, for some dogs, having it done too soon can have potential drawbacks that outweigh the benefits.

Two separate studies published in 2020 by University of California-Davis concluded that spaying dogs before they're fully grown can increase the risk of a number of serious health problems, including cancers like osteosarcoma, hemangiosarcoma, mast cell tumors and lymphoma. Early spay or neuter can also increase your dog's likelihood of developing joint injuries or disorders like hip or elbow dysplasia or a ruptured cranial cruciate ligament (CCL). Additionally, early neutering was found to be associated with declining cognitive function in aging male dogs.

In light of these findings, it might be better to wait until your dog is finished growing to have them spayed or neutered. The age at which this occurs varies by dog breed, but generally, small and toy breeds finish growing between six to eight months; medium dogs are usually fully grown by a year. Large and giant breeds, on the other hand, don't reach their full height until 18 to 24 months of age.

Breed-specific health predispositions might also factor into your decision. If your dog has a genetic predisposition toward mammary cancer but does not have a predisposition for any conditions that could worsen with early spaying, then it might be wisest to spay her before her first heat.

What About a Partial Spay?

For female dogs, there is an alternative to early spaying that offers many of the same benefits of spaying without the potential drawbacks. Partial spay, also known as ovary-sparing spay, is a procedure that removes only the uterus but keeps the ovaries intact, allowing your dog to enjoy the health benefits of elevated estrogen while still removing the chances of pyometra, uterine cancer or unwanted pregnancy.

Partial spay does nothing, however, to lower your dog's risk of mammarian or ovarian cancers. Ovarian cancer in dogs is rare, however, and the survivability chances of these types of reproductive cancer tend to be higher than those of the cancers that spaying too early can help to bring about.

The bottom line is that there is no general best age for when to spay a dog, nor for when they should be neutered. The best age depends on your individual dog's size, breed and health predispositions, and is something that can only be determined by you and your vet.

Dog Spay/Neuter Timeline: What to Expect

Spaying or neutering your dog is a major event for you both. Here's what you can expect.

Pre-surgery

Before the procedure, the vet will need to prep your dog for surgery. They'll do a thorough examination of your dog, including blood work, to ensure that your pup is healthy enough to undergo surgery. You'll also need to provide the vet with your dog's complete medical history, including their vaccination history and any prescription medications they take.

Depending on your vet, this may be done at a separate appointment before scheduling the procedure, or it may be done the morning of the surgery. In the latter case, your vet will likely contact you if they find anything that prevents them from going through with the procedure.

The day of surgery: How a dog spay/neuter works

Your vet will likely instruct you not to give your dog anything to eat or drink after a certain time the night before the surgery. Typically, you'll drop your pooch off at the veterinary clinic early in the morning on the day of the surgery and pick them up by the end of the day.

While your dog is there, they'll be injected with pain medication and then placed under general anesthesia while the vet performs the spay or neuter surgery. Afterward, they'll be moved to an area where they can be closely monitored and kept comfortable while they wake up from the anesthesia. Your vet will most likely give you a call at this time to let you know how your pup is doing and how the surgery went, as well as an approximate time you can expect them to be ready for pickup.

When you pick up your dog, you'll be given a set of post-op recovery instructions, and you may also be provided with medications to give your dog at home. Your dog will likely still be groggy from the anesthesia and may need to sleep it off overnight. It can take up to 24 hours before anesthesia completely wears off and they're back to feeling fully awake.

Recovery from a spay/neuter

You'll need to provide your pup with a quiet place where they can rest in undisturbed comfort. And while it may be a bummer for your dog, making them wear an Elizabethan collar, or E collar, is a must. "It is important to protect your pet from licking his/her incision, which could potentially cause an infection or delay healing" says Dr. Kathy Wiederkehr (Wentworth), veterinarian.

Follow your vet's care instructions carefully, administering medications at the appropriate intervals and watching them closely for signs of post-surgical complications or infections. For 10 to 14 days, you'll need to limit your dog's activity and give them plenty of rest, and refrain from bathing, swimming or any other activities that might get their surgical wound wet. Your vet should also let you know if or when stitches will need to be removed, as well as signs to watch for that mean you should call them about your dog's condition.

Post-recovery from a spay/neuter

Your pup should soon be fully recovered and back to their normal self. While their fundamental personality won't change, you might notice some behavioral changes, usually for the better. While neutering is no guarantee that these behaviors will stop, your neutered male may stop humping and trying to run away and may not spray urine to mark his territory as much as he used to, especially in the house. Aggression toward other dogs may die down as well.

Behavioral differences in spayed females are usually less marked, but your girl might have less energy and more of an appetite, so you'll need to monitor her daily food intake and encourage exercise to ensure she doesn't gain weight. Because the decrease in sex hormones is likely to slow metabolism in either gender, you'll need to do this with your male dog, as well.

The Cost of a Dog Spay vs. Neuter

While the costs of spaying and neutering can vary from one clinic to the next, you can expect to pay an average of $315 for neutering a dog and $465¹ for spaying one in the U.S. according to CareCredit's 2023 Average Procedural Cost study.* Depending on the location, low-cost spay and neuter clinics may offer neutering for as little as $55 and spaying for $60.¹

Busting Dog Spay and Neuter Myths

A lot of myths and misconceptions surrounding both spaying and neutering may keep some responsible dog parents from making the best choices for their dog's health. Here are some of the most common myths.

Myth: Spaying and neutering both cause dogs to gain weight.

While it's true that a reduction in sex hormones will slow your pet's metabolism, weight gain is primarily caused by an inappropriate diet and not enough exercise, regardless of whether your dog's sex organs remain intact. Your dog's age, breed and lifestyle have far more impact on their weight than whether they're spayed or neutered.

Although you should factor their slower metabolism into deciding what and how much to feed your dog, feeding them an appropriate amount of food that's tailored to their breed, life stage and activity level, combined with plenty of exercise, will help keep a healthy dog fit and trim.

Myth: Neutering will cause a male dog to be less masculine or less effective at protection.

It's true that neutering your male dog will decrease his testosterone levels. High levels of testosterone in intact males are responsible for behaviors like marking inside the house, mounting your leg, picking fights with other male dogs and running away from home to seek a mate. They're also responsible for elevated risk of prostate disease and testicular cancer.

But testosterone is not what drives your male dog's protective or territorial instincts, nor is it what shapes his natural temperament. Neutering your dog will have no effect on his desire to guard his territory and protect his family and/or livestock from potential threats.

Whether or not a dog is good at protection or guarding has much more to do with breed, environment and overall health.

Myth: It's healthier for a female dog to have at least one litter of puppies before being spayed.

The truth is that pregnancy places a lot of stress on a female's body and opens them up to pregnancy complications such as dystocia, a condition that prevents puppies from being able to pass through the birth canal. This requires an emergency C-section, which is both costly for a pet parent and requires a long recovery time for your dog.

Additionally, there is no scientific evidence that allowing a dog to go through at least one pregnancy offers any health benefits to the dog.

On the other hand, spaying your dog before her first heat cycle eliminates any chance of pyometra and uterine and ovarian cancers and vastly reduces her risk of developing mammary cancer. The risk of mammary cancer goes up with each heat cycle, until after her fourth heat, at which point spaying would do nothing to reduce cancer risk.

Myth: Spaying and neutering are expensive procedures.

Spaying and neutering may be somewhat costly, depending on where you have the procedure done, but both procedures are far less expensive than treating any of the health complications that could arise from leaving your dog's reproductive organs intact. And when compared to the costs and effort involved in both raising a litter of puppies and placing them with good homes, the cost of a spay or neuter becomes a lot more attractive.

If you struggle to afford spaying or neutering your dog, check with your veterinarian or contact your local animal shelter for information about low-cost spaying or neutering services in your area. Many communities offer such services at a discount.

Myth: It's too dangerous to put my dog under anesthesia.

While there's always some risk involved with surgery, both spaying and neutering are incredibly safe, per Dr. Kathy Wiederkehr (Wentworth). "Anesthesia has advanced tremendously in the veterinary world. Safer anesthetics, protocols and careful monitoring have reduced the risk of anesthetic complications significantly," she says.

While the best age to spay or neuter will vary from one dog to the next, one thing is certain — evidence weighs heavily in favor of getting your dog spayed or neutered at some point. Whether you have a male or female canine companion, getting this procedure done will have a positive impact on their overall health as well as their behavior, improving your chances of enjoying your pup for years to come.

Financing Dog Neuters and Spays With the CareCredit Credit Card

Your dog is your best friend, and you want to make sure they get the very best. That's why the CareCredit credit card is here to help you manage the costs of diagnostics and treatment for neuters and spays.** Use our Acceptance Locator to find a veterinarian near you that accepts CareCredit. CareCredit is there for you and your pet every step of the way; continue your wellness journey by downloading the CareCredit Mobile App to manage your account, find a provider on the go and easily access the Well U blog for more great articles, podcasts and videos.

In addition to pet care, you can also use your CareCredit credit card for dentistry, cosmetic, vision, hearing, health systems, dermatology, pharmacy purchases, spa treatments and so much more within the CareCredit network. How will you invest in your health and wellness next?

Expert Reviewer

Dr. Kathy Wiederkehr (Wentworth), V.M.D.

Dr. Kathy Wiederkehr (Wentworth) has been practicing veterinary medicine at pet care facilities in California since 2001. Most recently, she served as medical director of the VCA PetPoint Medical Center and Resort in Irvine. She is a graduate of the University of Pennsylvania School of Veterinary Medicine and became board-certified as a diplomate in Canine and Feline Practice by the American Board of Veterinary Practitioners in 2010.

Author Bio

Jean Marie Bauhaus is a freelance writer and novelist who has been writing pet content since 2013. Her work has appeared on Forbes.com, Hill's Pet, Chewy, AKC.org and more.