When & Why You Should Spay or Neuter Your Dog

• This article has been reviewed by a pet health professional. It is not a substitute for professional veterinary advice.

Being a pet parent comes with plenty of decision-making, and one of the biggest is when to spay or neuter your four-legged pal. For those new to the subject, spaying is for female dogs while neutering is for male dogs. Although the procedures are different, the health, behavioural, and community benefits are similar.

Let’s take a closer look at the benefits of spaying and neutering, from the recommended age to spay or neuter, how the surgery works, and some of the most prevalent myths around the simple and life-saving operation.

Benefits of Spaying and Neutering Your Dog

Behavioural benefits

Spaying or neutering, also known as “altering,” can potentially reduce some problem behaviours, says Dr Jo Myers, DVM, a veterinarian at Vetster, a pet telehealth company.

A dog’s reproductive hormones are linked to undesirable behaviours, such as urine marking, roaming, and property destruction. These occur “in an effort to breed,” she continues. However, spaying and neutering involve removing organs (the ovaries or testes) that contribute to producing these hormones. Spaying and neutering, in particular, can reduce humping behaviours in older puppies.

It’s important to note, adds Myers, that “spaying and neutering are not substitutes for training.”

Health benefits

With the ovaries and testes removed, diseases affecting these organs—including cancer—can’t occur, Myers explains. In addition, spaying or neutering “reduces the risk of illnesses affecting the remaining reproductive organs, since ovarian or testicular hormones do not stimulate them,” she says.

One study revealed that spayed female canines are four times less likely to die from mammary cancer compared to non-spayed females. Meanwhile, “prostate disease is much less likely to affect a neutered [male] dog,” notes Myers.

Research has also found that neutered or spayed dogs live longer, with life expectancy increasing by 13.8% in male dogs and 26.3% among females.

Community benefits

Spaying and neutering are essential in maintaining dog population numbers and “decreasing the need for euthanasia of unwanted animals,” Myers says.

According to the Spay-Neuter Assistance Program, one unspayed female dog and her offspring can produce over 500 puppies in just seven years. The RSPCA advises that around 664,000 dogs enter the UK’s shelter system each year. Sadly, with no place to go, many of these canines are euthanised.

At What Age Should I Spay or Neuter My Dog?

There’s “a lot of debate in the veterinary field” regarding the optimum age to spay or neuter dogs, says Dr. Erica Thiel, midwest area medical director at IndeVets, a practice offering relief services to veterinary clinics across the nation. However, Thiel says, there are some general recommendations from the American Animal Hospital Association:

Age recommendations for spaying/neutering:

• Males (small breed): 6 months of age
• Females (small breed): 5-6 months of age (before anticipated heat cycle)
• Males (large breed): Around 9-15 months, after growth stops/skeletal maturity is reached
• Females (large breed): Around 5-15 months, after growth stops and bones are set

Why small and large breeds have different timelines

“Some studies have shown spaying/neutering a large breed dog before they have reached full growth could inhibit their growth due to altering their hormone balance,” Thiel explains. This leads “to an increased risk for orthopaedic issues later in life.” In addition, spaying often occurs earlier than neutering because “if a female is spayed before or just after her first heat cycle, the chances of that dog developing mammary cancer greatly decreases.”

Thiel says there is an argument that owners should wait longer to sterilise their pet, as some research has shown sterilised dogs have an increased risk of particular cancers compared to intact dogs. “However, many of these are small, limited studies, and further research needs to be done to determine the validity of these claims,” she states.

Katie Ford, BVSc CertAVP(SAM) MRCVS, a veterinary surgeon, notes that mindsets around procedure timings have changed significantly in the last decade. “As more evidence emerges regarding neutering, the veterinary profession is taking a very individualised approach, highlighting that there’s no one-size-fits-all solution.”

“The best time to spay or neuter a dog definitely varies depending on [the pet’s] gender, but also their breed, size, and individual circumstances, including their medical and behaviour history,” she asserts. “It’s important for pet owners to have open conversations with their vet teams to determine the right timing.”

How Does Spaying and Neutering Happen?

Whatever age you spay or neuter your pet, the simple surgical procedure for each is relatively straightforward and quick. Neutering can take as little as 5 to 20 minutes, while spaying can take 20 to 90 minutes.

Neutering

An incision is made either into the scrotal sac or just in front of it, with the latter being more common, says Thiel. When the testicles are exposed one at a time, “the associated vessels (or spermatic cord) are tied off with suture material. The spermatic cord is cut, and the testicle is removed,” she continues. The incision is then closed with sutures.

Spaying

An incision is made into the abdomen, where the two uterine horns are found. “The uterine horn is localized and followed up to the ovary. The associated vessels are tied off with suture material, and the ovary is cut away from the body wall,” explains Thiel.

From there, the same procedure is performed on the other uterine horn and ovary. Then, “the uterine body itself is isolated and subsequently tied-off,” Thiel continues. “It is cut, and both ovaries, both uterine horns, and a portion of the uterine body is removed.” After checking for bleeding, sutures are used to close the incision.

The risks of leaving a dog intact, especially a female, far outweigh the risks of having your dog spayed or neutered in the majority of cases.

Associated risks and concerns

Thiel notes that any procedure involving anaesthesia has an inherent risk of complications. “However, if your dog is young and otherwise healthy, has a benign physical exam, and their pre-surgical blood work reveals normal liver and kidney function, these risks should be very minimal,” she says.

Some post-surgical complications can include drainage from the incision site, reaction to the sutures, infection, and internal bleeding. “[But] all of these complications are very rare, especially if an owner closely follows their veterinarian’s post-surgery instructions,” Thiel continues. “The risks of leaving a dog intact, especially a female, far outweigh the risks of having your dog spayed or neutered in most cases.”

How Long Does Recovery Take?

Every dog’s recovery time from surgery is a little different, depending on factors like size, age, and health. Most male dogs fully recover from being neutered in 7 to 10 days, while female dogs recover from spay surgeries in 10 to 14 days.

According to Ford, a female dog’s longer recovery time is usually a result of the more invasive nature of a spay surgery. All pups should begin to feel better 24 to 48 hours after their operation.

But that doesn’t mean they can have the run of the house, Ford cautions. Your vet will typically advise you to keep your dog from running and jumping. You’ll also be equipped with an E-collar or a recovery suit to prevent your dog from licking their incision.

Following either procedure, bruising, swelling, or discolouration may occur at the incision site. Your vet will prescribe medication to help ease discomfort, and “your dog may be more tired and have a decreased appetite for up to 24 hours after the procedure,” notes Thiel.

Remember that dogs don’t have the same awareness of what has happened to them as humans do—or much ability to self-moderate. So it’s important to keep things calm and set your dog up with a cosy, quiet spot to rest and heal.

Costs

Where you get your dog spayed or neutered will have a significant influence over the procedure cost, according to the PDSA. Your dog’s size and gender will also make a difference.

Speak to your vet about the cost of standard and keyhole sterilisation. Keyhole surgery costs more but may lead to a lower risk of postsurgical pain and complications and a quicker recovery time. The RSPCA and PDSA may be able to help pet parents access lower-cost treatments.

Pet insurance is unlikely to cover for sterilisation costs, as insurers consider it to be a preventive treatment, like vaccinations, that’s an inherent part of having a pet. Outside of specific plans, they don’t usually fund these types of treatments. However, speak to your insurer if you have any questions.

Spay & Neuter FAQ

Here’s what people most often ask us about spaying and neutering.

Will spaying/neutering make my dog fat?

Spaying/neutering can lead to changes in metabolism, but these naturally occur throughout a dog’s life anyway. It’s how an owner responds to these fluctuations that will determine if a dog gains weight.

“Being aware of this [metabolism change] means we can make proactive lifestyle choices to reduce the risk of weight gain from the start,” says Ford. “This might include reducing food or changing to a life stage-appropriate diet. Veterinary teams are always happy to advise on individual circumstances.”

Will neutering calm my dog down?

Myers reveals that scientific studies assessing the incidence of aggression between “intact” and “altered” dogs do not indicate a significant difference between the two groups. “One possible explanation is that aggression is a multifactorial behaviour, and reproductive hormones play only a small role, if any.”

In fact, “depending on individual circumstances, sometimes neutering can actually lead to an increase in fearful behaviours in some dogs, especially if neutering is before puberty,” adds Ford. “I’d always suggest discussing your dog’s individual circumstances with your veterinary team.”

Will spaying/neutering change my dog’s personality?

Absolutely not, assures Myers. While the process typically reduces the occurrence of problematic behaviours rooted in reproductive hormones, “it doesn’t alter your pet’s personality,” she says. If anything, “your pet’s unique personality will still shine through, perhaps even more brightly in the absence of the instinctive drive to mate.”

Myth: My dogs are siblings, so they won’t mate

You might like to think your dogs know the sibling boundaries, so they won’t need altering. However, “it’s important to understand that dogs, like many animals, may not have a natural aversion to mating with their siblings,” shares Ford.” In the animal kingdom, mating behaviours are often instinctual and not influenced by familial relationships.”

Takeaway

Spaying and neutering are essential elements of pet parenthood and play a vital role in various health outcomes and in controlling the canine population.

Experts believe the optimum age at which you should spay or neuter your dog differs between breeds, genders, health history, and behaviour traits. It’s a good idea to speak with your vet to make an informed decision based on your dog’s well-being and don’t hesitate to raise any questions or concerns.