Advantages and Disadvantages of Spaying or Neutering Your Dog

puppy on womans shoulderA recent study shows that if you have a small breed dog or mixed breed weighing under 42 pounds, the age at which you spay, or neuter has no impact on the incidence of getting a joint disorder or cancer. The exception is Shih Tzu ad Boston Terrier. For Boston Terrier males, the recommendation is after one year of age. The recommendations for the female Shih Tzu breed is spaying after two years of age. Large breed dogs should wait until after 1 year of age. Other breeds like Golden Retriever females should not be spayed due to the higher incidence of cancer. The bottom line is to check with your veterinarian about your specific breed.

Whether you’ve adopted a puppy or an older dog, the choice to spay or neuter is one of the first ones you’ll need to make, and it’s crucial for his or her long-term health. It’s not just about preventing unwanted puppies, either. 

Spaying or neutering can minimize or even eliminate many serious health risks for your new family member. Let’s take a look at six ways spaying or neutering is crucial for your dog’s health and longevity.

Spaying and neutering dogs not intended for breeding is a practice that has been a best practice for decades. The benefits of this practice are many and widely known. The most obvious, is pet population control. Sadly, despite this practice, millions of unwanted pets enter shelters every year, many of which never find permanent homes. 

That is not to say that there aren't negatives.  If so, what are they? Can they be avoided? This has become a hot topic in veterinary medicine and has sparked considerable  research in this area. Which is outlined below.

Health Benefits

The health benefits associated with spay/neuter are generally associated with disease avoidance.

The obvious preventable diseases are

  • ovarian
  • uterine
  • testicular cancer because the organs are removed

Male Dogs

For male dogs, other diseases potentially avoided are:

  • prostatic hyperplasia
  • perianal tumors
  • perinea! hernias. For female dogs, the list includes mammary cancer and pyometra.

Female Dogs

  • mammary cancer 
  • pyometra (reproductive tract infections)(

Top Reasons for Spaying or Neutering Your Dog

1. Dogs Who Are Spayed or Neutered Live Longer Than Dogs Who Aren't

Science shows that the lifespan of a dog who has been spayed or neutered is significantly longer than the lifespan of one who has not. 

According to one study done by the University of Georgia on 70,000 pets, neutered male dogs live 13.8 percent longer, while spayed female dogs live 26.3 percent longer than their unaltered counterparts. The study also showed that the average lifespan of unaltered dogs was 7.9 years, while altered dogs live an average of 9.4 years or more.

And, Banfield Pet Hospital conducted its own study using its database of 2.2 million dogs. Their research showed that spayed female dogs live 23 percent longer and neutered male dogs lived 18 percent longer than unaltered dogs.

Those are some very persuasive statistics, but why do altered pets live longer? Part of their longevity can be traced back to a reduced urge to roam. Neutered and spayed dogs tend to stay closer to home, which means less risk of injury, less exposure to infection and disease, and less fighting with other animals.

Sadly, un-altered dogs make up a whopping 85 percent of dogs who are hit by cars. The bottom line is neutering or spaying your dog is a crucial step for keeping him or her safe and healthy at home.

2. Spaying Stops Female Dogs from Going into Heat

Female dogs can go into heat up to twice each year starting at about six months of age. During the heat cycle, an unspayed female dog may bleed or have discharge from the vagina. 

She will often urinate more than usual to mark her territory and signal to males that she’s in heat. She will also be more likely to run off in search of a mate or attract unneutered male dogs into your yard. 

Every dog is different. Some become overly affectionate when they’re in heat. Unfortunately, others may become cranky or aggressive with other pets and people. Either way, she’ll need to be supervised closely, especially around young children, and kept away from any intact males in or outside the home. 

Aside from the risk of an unexpected litter of puppies, going into heat can be very stressful for your dog. She’ll likely be very anxious and possibly even agitated every time she’s in heat. Repeating this cycle of stress over and over again can be hard on her health. 

3. Spaying Prevents a Dangerous Infection Called Pyometra

Every time your dog goes into heat, she can develop a life-threatening uterine infection called pyometra. This happens when the uterus fills up with pus and bacteria and can result in severe illness or death without expensive treatment. According to veterinarians at Bond Vet, where you can spay & neuter your NYC pet, spaying your dog eliminates the risk of this potentially fatal uterine infection.

4. Spaying Lowers the Risk of Breast Cancer

Female dogs can get breast cancer just like humans can. Having your female dog spayed before she goes into heat for the first time lowers her risk of getting breast cancer significantly.

Statistics show that more than a quarter of unaltered female dogs will develop mammary tumors at some point in their life. About half of those tumors will be malignant and all of them should be surgically removed as a safety precaution.

5. Neutering Removes the Risk of Testicular Cancer

When a male dog is neutered, his testicles are removed, which effectively eliminates the risk of testicular cancer for his entire life. This is especially important for dogs who have one or two undescended testicles, which greatly increases their risk of developing testicular cancer. 

6. Neutering Reduces Prostate Conditions

Although neutering won’t prevent prostate cancer in your dog, it will lower his chances of developing prostatic hypertrophy, or an enlarged prostate. Unaltered males are also more prone to prostatitis, which is a bacterial infection in the prostate. 

Neutering also reduces the likelihood of your dog developing a perineal hernia, which may require expensive surgery to correct.

Reasons to Not Spay or Neuter Your Dog

Cognitive Decline

The acceleration of cognitive decline as neutered pets age devoid of sex hormones has become a concern, based on studies in humans looking at the association between Alzheimer's disease and declining sex hormones in aging people. Dr. Benjamin Hart showed some years ago that castrated male dogs had a higher incidence of cognitive dysfunction than intact dogs. Dogs are living longer, with cognitive dysfunction becoming a significant quality-of-life issue, both for the dogs and those who love them. 

Bone Growth Issues

The effect of spay/neuter before bone growth-plate closure in larger dogs has come into question. Studies show an increase in bone length when these dogs are spayed/neutered early. This increased bone length is thought to potentially alter natural joint angles, thereby adding to the increased likelihood of joint disorders in these dogs. 

Joint Disorders and Cancer

There is some evidence that there is a connection between increase in cancers and joint disorders and spaying/neutering. There are some theories as to how this happens such as the way hormones work. For example, the 

gonads ( testes and ovaries) produce the sex hormones (testosterone and estrogen.)  Estrogen and testosterone are controlled by other hormones,  which are luteinizing hormone (LH)

and follicle-stimulating hormone (FSH) . Both of these homes come from the pituitary gland and (GnRH0 which is gonadotropin-releasing hormone, a hormone that comes from the brain's hypothalamus.

In dogs that are not spayed or neutered, this keeps hormone levels at expected levels. 

When you spay or neuter and remove the gonads this also eliminates any sex hormones. Without negative feedback from the sex hormones, levels of hypothalamic and pituitary hormones rise and become high. 

This effected was researched in a study that examine the impact of raised amounts of  LH and how ti negatively impacts the a dog that has been spayed or neutered. These LH receptors have been found in many of the non-gonadal tissues involved in diseases that are found more commonly in spayed/neutered dogs than in intact dogs. Examples include: 

The Bottom Line

Dealing with a surprise litter of puppies is a huge responsibility. Raising them in a clean, healthy environment until they’re at least eight weeks old is a lot of work. You also have to find them suitable homes once they’re weaned. And, the health benefits of spaying or neutering your dog are quite significant. At the end of the day, the rewards of spaying or neutering significantly outweigh any potential risks or drawbacks. 

There is also no clear cut answer for when to spay or neuter a dog. The answer changes based on dog size and breed. For example Boston Terrier males have a higher incidence of cancer when neutered before a year of age. That is not the case if you have small breed togs that are not Boston Terriers or Shih zus.

For large breed dogs it is generally recommended that owners wait until one year of age to spay and neuter, as the incidence of joint diseases and cancer was lower after the one year mark.