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When Should I Neuter Or Spay My Dog?

Written by Tamsin De La Harpe


Black labrador wearing a vet cone

When Should I Neuter Or Spay My Dog? 

The ever-increasing number of stray dogs makes spaying or neutering your dog a necessity. Dog breeding is sensitive, and most people lack the skills to do it properly. What’s more, leaving your dog intact can also lead to unwanted hormonal issues such as aggression or marking in the house.

However, it’s also essential to know when to neuter or spay your dog, because doing it too soon or too late can cause behavioral and even health issues.This article covers all you need to know about the surgical procedures of spaying and neutering, including the age at which you can safely perform them.

At What Age Is It Better to Neuter a Male Dog?

Neutering a male dog is sometimes a controversial issue, as many owners don’t like to do it as they’re applying human emotion to the situation. Experts also disagree on the best times. However, in general, the size of your dog is the best indication of the rough age that they should be neutered.

At What Age Should I Neuter My Small Breed Dog? 

Small breed dogs enjoy the privilege of early neutering with minimal health complications. It’s best to neuter them around the 6 month mark, to minimize the effect of hormones around the time they reach puberty. A dog is a small breed when the adult weight is below 22 pounds. 

According to the AAHA Canine Life Stage Guidelines, you can neuter small breeds at 6 to 9 months of age. Small breeds can be cheaper to neuter because the small size requires fewer anesthetic drugs and decreased dosages of pain medication. 

Vulnerability to orthopedic issues increases the health risks concerning neutering your dog. Small dogs suffer from fewer orthopedic problems such as hip dysplasia compared to their larger counterparts, making it possible to neuter them early. 

At What Age Should I Neuter My Medium Breed Dog?

Dogs weighing between 25 pounds and 55 pounds are medium-sized breeds. They are neither small nor large. Examples of medium breeds are Bulldogs and Cocker Spaniels. You can get your medium-breed dog neutered between 6 months and a year old.  

Like small breeds, medium-sized dogs are less likely to develop medical issues due to early neutering. The pup can safely undergo the procedure once they attain sexual maturity at around 6 - 9 months of age. 

However, keep in mind that some medium breeds are prone to joint issues. When it comes to dogs like German Short-Haired Pointers and Australian Shepherds that can develop joint issues, it’s best to wait until the growth plates in their joints have closed. 

Puppies have growth plates of cartilage in the long bones of their legs. Overtime, this cartilage turns to bone, or ossifies. A lack of hormones after neutering can delay this process. This can lead to cartilage injuries that may later become degenerative joint disorders.

At What Age Should I Neuter My Large Breed Dog?

You should get your large breed dogs neutered after growth stops at around 12 to 18 months. Neutering your giant breed pup any sooner poses the risk of future health conditions such as Lymphoma and hip dysplasia. Like with some medium-sized dogs, it’s important to let your vet check that your puppy’s growth plates have closed before you neuter them. The larger the breed, the longer this can take. 

Large dogs, such as the German shepherd, weigh over 55 pounds. Giant dog breeds like the Great Dane are much bigger and can weigh over 75 pounds. Large and giant breeds reach physical and sexual maturity much slower than small breeds at 16 - 18 months old. 

Risks of Neutering Your Dog Too Early

Advocates of neutering pets push forward the narrative that neutering is full of benefits to dogs' long-term health. The thorn in the roses regarding neutering is the health risk associated with getting it done too early. 

Despite all the benefits of neutering, timing is a very important consideration. Neutering too early is possibly exchanging one set of problems for another, which is counterproductive. Recent research suggests it’s better not to neuter too early.

  • Health Issues 

Several studies have shown that dogs neutered in their puppyhood have an increased risk of developing health issues later in life. Large dog breeds are particularly sensitive to early neutering, which can result in the emergence of health complications. 

Research found health issues linked with neutering dogs before one year. The study found that dogs, particularly the larger and heavier ones, are at risk of joint problems and some cancers..  

One study by UC Davis was performed on 35 different dog breeds while the other on mixed breeds. The survey of the 35 breeds added to prior research done on Golden Retrievers, Labrador retrievers, and German Shepherds. It showed that health risks based on the age of neutering varied widely on the breed. 

The study found that vulnerability to joint disorders like hip and elbow dysplasia is generally related to body size. Small dog breeds such as the Maltese and Chihuahua didn't show increased joint disorders. So, neutering large dogs too early is very bad for their joints and long-term well-being.

According to Benjamin Hart who was in charge of UC research, the risk of joint disorders is three or four times greater than that of those left intact. 

  • Interference With Sex Hormones 

Early-age neutering done before puberty negatively affects hormones. Most dogs, especially large breeds, haven't achieved sexual maturity by six months. 

Neutering before 6 months greatly impacts proper bone development. Rising testosterone levels during puberty in intact dogs causes the growth plates in a puppy’s legs to close naturally. 

This rise in sex hormones doesn't happen for early-age neutered dogs, leading to a delay in closing the growth plates. The effect is that the long bones continue to grow and the cartilage between the plates doesn’t turn into bone when it should. This leads to health problems like cranial cruciate ligament tears (CCT), common in dogs like Rottweilers. 

Dr. Kutzler, a veterinarian at Oregon State University, studied the effect of hormone loss on the mechanism of disease He stated that sex hormones such as Luteinizing Hormone (LH) exist in unhealthy concentrations in neutered dogs. This concentration increases the likelihood of developing health problems in those tissues. 

Risks of Neutering Too Late

Pet owners with older dogs often wonder if they can still neuter their pups. It is never too late to perform neutering for most dogs, even senior canines. Your vet will perform diagnostic tests to assess the anesthesia risks before neutering your pup. 

While there is an increased risk of surgical complications in older dogs, it's not significant enough to warrant avoiding the process altogether. Neutering your dog early — but not too early-—is beneficial to avoid the issues resulting from late-age neutering such as:

  • Unwanted puppies 

Curbing the animal overpopulation problem is the biggest reason for the emphasis on neutering pets. Millions of animals end up in shelters every year in the U.S, with less than half getting into forever homes. Shelters euthanize more than 1.5 million of these animals every year. 

The unfortunate truth is intact male and female dogs contribute to this high number of shelter admissions. When you delay neutering your dog, the chances are that they will impregnate female dogs resulting in homeless puppies. 

Neutering helps fix the overpopulation problem by ensuring that only puppies that have a home are born. It’s not uncommon for intact dogs to be owned by "back-door" breeders who aren’t knowledgeable in the intricacies of proper breeding. 

  • Roaming and urine marking 

When female dogs are in heat, the male dogs get into a frenzy. Intact dogs get a strong urge to spray during the mating season which can be quite annoying to pet owners. Neutering resolves this issue because neutered dogs don't take part in mating. 

Intact dogs have a habit of roaming as soon as they smell a female dog in heat. Dogs that leave to find females in heat can stay away for weeks, and are vulnerable to accidents, being stolen, or picked up by animal control.

If your pup has urinary incontinence, read our article/learn/dog-health/dog-incontinence-causes-and-solutions-for-canine-bladder to learn how to deal with it. 

If your dog tends to run away, you can see our article here./learn/dog-lifestyle/why-do-dogs-run-away

  • Decreased Life Expectancy 

A study by the University of Georgia based on 70,000 animals found that the life expectancy of neutered males was 13.8% longer than intact dogs. A variety of factors such as a reduced urge to roam mean that neutered dogs simply live longer than unneutered dogs.

Intact males that roam are likely to get into fights or road traffic accidents. It is not uncommon for dogs to not find their way home after leaving to mate but even if your dog comes back, they may be really badly hurt. 

  • Behavioral issues 

Unneutered dogs usually display a variety of unwanted behaviors, ranging from the embarrassing to downright dangerous. This can include:

  • Aggression with other dogs, especially males
  • Becoming overly territorial
  • Humping objects, other dogs, and people
  • Marking in the house
  • Increased dominance.

So, having looked at neutering male dogs, what about female dogs?

At What Age Should I Spay My Female Dog? 

 Like male dogs, the age at which you should spay female dogs varies based on the breed's size. The AAFA guidelines give beneficial insight into the age at which female dogs should be spayed. 

The surgical procedure of spaying involves removing a female's reproductive organs, such as the ovaries and part of the uterus. Spaying is beneficial because it curbs the animal population crisis. Spaying also reduces the risk of mammary adenocarcinoma (breast cancer) and pyometra (life-threatening uterine infection).

At What Age Should I Spay My Small Breed Dog?

You can spay your small breed dog prior to their first heat (estrous cycle). Small breeds face minimal health complications resulting from early-age spaying. Generally, it’s best to spay them at roughly 6 to 7 months, to make sure you spay before the first heat. If your dog does go on heat, you will need to keep them indoors for about three weeks, and spay them immediately after.

At What Age Should I Spay My Medium Breed Dog?

Like small breeds, you can get your medium-sized female dogs spayed prior to their first heat cycle. To compensate for the difficulty in detecting the heat cycle, some vets advise spaying at around six to eight months.

At what age should I Spay My Large Or Giant Breed Dog? 

A large breed dog like a Bullmastiff will generally have her first heat around 8 months. Some giant breeds can take much longer, waiting up to a year or more. Either way, it’s best to spay before the first heat. The common age is 7 to 12 months. 

The subject of when to spay large dogs is much more nuanced as a blend of several factors influences it. Some of these factors include the dog's disease risk, lifestyle, and the results of the anesthetic analysis done by the vet. 

Frequently Asked Questions 

  • Does a female dog get spayed or neutered?

A female dog gets spayed. Spaying is the surgical removal of a female dog's ovaries and uterus. Spayed dogs cannot get pregnant because they lack the sexual organs responsible for the pregnancy. 

  •  Does a male dog get spayed or neutered?

A male dog gets neutered as a form of birth control. A neutered male dog has the testicles removed and cannot impregnate a female dog. 

  •  Is it better to wait to neuter a dog?

The time you need to wait to neuter your dog depends on the breed’s size. You can neuter small breeds at 6 to 9 months but wait until 9 to 15 months to get your large dog neutered. It’s better to wait until the growth plates in large breed dogs are closed, but not to wait so long that your dog develops hormone-related behavioral issues.

  • How do you know when it’s time to neuter your dog?

You can know the right time to neuter your dog based on age. The right time to neuter a small dog is around 6 - 9 months. A large dog takes much longer, up to 15 months, to get to the right time to neuter. For dog’s that are prone to joint and ligament issues, you can wait for your vet to confirm that the growth plates in their legs are closed before neutering.

Final Thoughts 

Neutering and spaying are effective forms of birth control that minimize the number of dogs in shelters. Small breeds can be neutered and spayed as early as six months. Large breeds have to wait until they are around one year to avoid joint issues like hip dysplasia.