Many dog owners struggle with the question of whether to spay or neuter their pets. Unless you're a responsible breeder or you keep show dogs, usually it's best to have them “fixed," not only to prevent unwanted puppies but also for a whole host of health reasons. But what's the best age 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.1
- Neutering is the removal of a male's testicles and associated structures.1
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 several benefits that may lead to a longer, healthier life.
Benefits of spaying a female dog
In female dogs, spaying is the only known way to address a number of issues, including:
- Preventing pyometra: Pyometra is an infection of the uterus that is extremely serious and could be fatal if not quickly treated.2 Surgical removal of an infected uterus is also far more dangerous and expensive than having your dog spayed while her uterus is healthy.3
- Reducing cancer risk: Spaying can help reduce the risk of your pet developing mammary cancer, which is malignant in approximately 50% of cases.4
- Resolving heat-related symptoms: Unwanted attention from male dogs, bloody vaginal discharge, unpleasant odor, and estrus-related behavioral issues like irritability and restlessness can all be prevented by spaying your dog.3
Benefits of neutering a male dog
Neutering your male dog can address issues including:
- Lowering testicular cancer risk: Neutering eliminates any chances of testicular cancer and reduces the risk of other health issues relating to the prostate.1
- Reducing unwanted behavior: Neutering also reduces problematic behaviors in male dogs, like inappropriate marking and hormone-related aggression toward other male dogs.1
- Resolve mating-related behaviors: It will also reduce the likelihood that your dog will try to escape and run away to find a mate, a behavior that can be dangerous both for him and for other dogs, especially if he's prone to fighting.1
What's the Best Age to Spay or Neuter a Dog?
When are dogs neutered, typically? For decades, veterinarians have encouraged pet owners to have their puppies neutered or spayed by six months of age, and sometimes earlier. But more recent research has discovered that early spay or neutering might not be recommended for all dogs.
Despite the health benefits of spaying or neutering your pup early, for some dogs, having it done too soon can have potential risks.
University of California-Davis findings
Two separate studies published in 2020 by the University of California-Davis concluded that spaying dogs of certain breeds before they're fully grown can increase the risk of several serious health problems, including cancers like osteosarcoma, hemangiosarcoma, mast cell tumors, and lymphoma.5 Spaying or neutering prior to skeletal maturity can also increase a dog's risk of developing joint injuries or disorders like hip or elbow dysplasia or a ruptured cranial cruciate ligament (CCL). 5,6
The first study published by Hart et al. examined the effects of early neutering on 35 different dog breeds. They concluded that there were major breed differences in the incidence of joint disorders and cancers. Small-breed dogs had no increase in joint disorders associated with neutering and only two breeds had an increased incidence of cancer.5 The study authors also produced suggested guidelines for neutering each of the 35 studied breeds.
The second study published by Hart et al. examined the incidence of joint disorders and cancer in mixed-breed dogs belonging to five different weight classes. The study found that neutering did not increase the occurrence of cancer in dogs in any weight category. However, neutering before the age of 1 year was associated with an increased risk of joint disorders in dogs weighing more than 20 kg. In dogs weighing less than 20 kg, neutering did not increase the risk of joint disorders.6
What does all this mean for your dog? The good news is that, according to the study authors, "Looking at the occurrences of these joint disorders and cancers, it is clear that most breeds are unaffected for these diseases by age of neutering."5 Most importantly, this study points out that there are breed differences - and in some cases, even sex differences - with regard to increased risk of joint disorders and certain cancers associated with spaying or neutering at various ages. The study authors conclude "In most cases, the caregiver can choose the age of neutering without increasing the risks of these joint disorders or cancers."5
What age to spay a dog?
In light of these findings, it is now recommended that the decision of when to spay or neuter a dog be made on a case-by-case basis. The best timing for your dog's spay or neuter surgery will depend on your dog's breed, weight, health, and family history. Your veterinarian is your best resource to help you decide on the best time to spay or neuter your pet.
For example, for a large or giant breed dog, to reduce the risk of joint disorders, your veterinarian may recommend waiting to spay or neuter until your dog is fully grown, which occurs around 18-24 months of age in these breeds. However, if your dog has a family history of mammary cancer, your veterinarian may recommend spaying prior to the first heat - around 6 months of age - to drastically reduce your dog's risk of developing mammary tumors later in life.
The bottom line is that there is no single 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 both you and your veterinarian.
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 thoroughly examine your dog, including performing blood work, to ensure that your pup is healthy enough to undergo surgery.3 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 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
Your vet will likely instruct you not to give your dog anything to eat after a certain time the night before the surgery.3 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 placed under general anesthesia while the vet performs the spay or neuter surgery.3 Afterwards, they'll be moved to an area where they can be closely monitored and kept comfortable while they wake up from the anesthesia.3 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. "There is a small risk of post-op infection that's almost always associated with the pet not wearing its E collar and licking the wound," says Dr. Andrew Moffatt, founder and CEO of VetnCare, Inc. in the San Francisco Bay Area.7
Follow your vet's care instructions carefully, administering medications at the appropriate intervals and watching your dog 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.3 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 minor 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 urinate to mark his territory as much as he used to, especially in the house.1
Behavioral differences in spayed females include the absence of estrus behaviors such as restlessness, increased urination, and irritability. However, because estrus - or coming into heat - only occurs once or twice a year for a female dog, behavior changes in females following spaying are much more subtle than those in males.
How Much Does it Cost to Spay or Neuter a Dog?
Costs of spaying and neutering can vary widely from one clinic to the next depending on your geographic region, the clinic's protocols, and the type of clinic where the procedure will be performed. The age and size of your dog also influence the cost of the procedure.
In the United States, a canine neuter procedure can cost anywhere from $150-600 and a canine spay procedure can cost $200-800. Shelters and spay/neuter clinics may offer some lower-cost options (these programs are funded by donations and grants that can help defray the program's operating costs). However, low-cost spay and neuter programs may not offer the same services as your veterinary clinic, so it is important not to base your choice on cost alone.
And keep in mind that various factors can impact the overall price of the procedure. Costs tend to go up when spaying a female who is either overweight, in heat, or pregnant, and methods such as laser or laparoscopic surgery may also cost more than the traditional method.
Busting Dog Spay and Neuter Myths
A lot of myths and misconceptions surround both spaying and neutering, which can keep responsible dog parents from making the best choices for their dogs' health. Here are some of the most common myths to be aware of.
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.8 Your dog's age, breed and lifestyle have far more impact on their weight than whether they're spayed or neutered.8 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.1,8
Myth: Neutering will cause a male dog to be less masculine or less effective at protection.
Neutering your male dog will indeed 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.3 They're also responsible for elevated risk of prostate disease and testicular cancer.1
But testosterone is not what drives your male dog's protective or territorial instincts, nor is it what shapes his natural temperament.1 Neutering your dog will not affect 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.1
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 body1 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. 3 The risk of mammary cancer goes up with each heat cycle. Dogs spayed prior to their first heat cycle have a 0.5% risk of mammary cancer compared to intact females, while those spayed after one heat cycle have an 8% risk, and those spayed after more than 2 heat cycles have a 26% risk.9 Thus, spaying prior to the first heat drastically reduces mammary 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.
But if you struggle to afford to spay or neuter your dog, check with your veterinarian or contact your local animal shelter for information about low-cost spaying or neutering services in your area.
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. Moffatt. "I think anesthesia these days in veterinary practice is done at a really high level, not dissimilar to that in a human hospital. And most hospitals these days are doing some pre-anesthetic work to further reduce that risk," he says.7
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've got a boy or a girl, 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.
CareCredit Financing for Dog Spays and Neuters
The CareCredit credit card provides a convenient way to pay for your dog's spay or neuter procedure and other health and wellness expenses, including exams, medications, and products at providers in the CareCredit network.* Apply today and continue your wellness journey by downloading the CareCredit Mobile App. You can find a provider on the go, manage your CareCredit account, and easily access the Well U hub for more great articles, podcasts, and videos. Use our Acceptance Locator to find a veterinarian that accepts CareCredit to help keep your pet healthy and happy for a lifetime of love.
Author Bio
Jean Marie Bauhaus is a freelance writer and novelist with eight years of experience. Her work has appeared on Hill's Pet, Chewy and AKC.org, and more.
Expert Reviewer
Dr. Elizabeth Racine is a small animal general practice veterinarian and freelance writer. She covers both human and veterinary medicine with a special interest in nutrition, internal medicine and veterinary behavior.