Should My Dog Be Spayed or Neutered?

By: Lori Teller, DVM, DABVP, CVJ

TVMA Member
Houston, TX

Published March 2016

The question of “Should my dog be spayedsurgical removal of the reproductive organs of female dogs or neuteredsurgical removal of a male dog's testicles?” used to be easy to answer. There are lots of great reasons to spay or neuter your dog while it is still a puppy. A dog that is spayed or neutered is less likely to develop wanderlust and exhibit aggressive behaviors and is more likely to live longer than those dogs that remain intact. Studies have shown that dogs that are spayed or neutered are less likely to die from trauma or infectious diseases. Females that are spayed earlier in life have a lower risk of breast and other cancers of the reproductive system and pyometra (a life-threatening infection of the uterus). And, of course, owners do not have to deal with the issues surrounding having a dog in heatthe stage in a female dog's reproductive cycle during which she becomes receptive to mating with males every six to 12 months. Males that are neutered earlier in life are less likely to develop that nasty habit of urine-marking indoors and are at a much lower risk of benign prostatic hypertrophy (a condition where the prostate becomes large and can cause straining to urinate or defecate).

Intact Dogs Pose Public Health Risks

Spaying or neutering your dog also has broader public health implications. Intact dogs often have the urge to roam. Intact male dogs can sense a female in heat from miles away and may throw themselves through plate glass windows or scale 8- to 10-foot fences in their quest to reach a female in heat. A female will search out a male with whom to breed. Unplanned pregnancies add to the pet overpopulation problem that exists in many areas of Texas. If these puppies can not be placed in loving homes, they may end up in shelters and euthanized. Roaming dogs may also lead to increased incidences of dog bites and the spread of parasites that are potentially contagious to humans, such as roundworms and hookworms. Currently in Texas, law requires that dogs adopted from shelters or releasing agencies must be spayed or neutered. This has made significant inroads in combating the pet overpopulation problem.

Pros and Cons of Delaying Surgery

So why would anyone consider keeping their dog intact or delaying surgery to spay or neuter it? Several recent studies on large-breed, purebred dogs show that there are some benefits to delaying surgery. Studies thus far have looked at the effects of spaying or neutering at different ages in Golden retrievers, Labrador retrievers, German Shepherds and Rottweilers. Studies continue on these breeds and others. While the results have been somewhat different for each breed, overall, dogs that remained intact or were spayed or neutered at a later age were much less likely to develop orthopedic problems, such as hip dysplasia and torn cranial cruciate ligaments, as well as certain cancers. However, they may be at higher risk for other types of cancers. So the question about whether or when to spay or neuter individual dogs becomes fuzzy. There are pros and cons to delaying this surgery. For small breed dogs, at this time, there do not seem to be major benefits to substantially delaying spaying or neutering your dog. Further research may reveal new information.

Caring For Intact Dogs

Also complicating this picture is if you, the owner, are prepared to live with an intact dog. Female dogs go into heat every six to 12 months, for an average of 12 to 21 days, depending on the breed. During this time, they will have a bloody vaginal discharge and may exhibit some behavior changes.  Some females may not show obvious signs of being in heat but can still become pregnant. They must be kept inside while in heat and only taken outside to potty while under your direct supervision. Intact male dogs can breed with females through crates and fences. Males may also exhibit behavior changes when sensing a female in heat and develop prostatitis (inflammation/infection of the prostate). Urine marking behavior is also more common in intact males. Finally, intact dogs are frequently not admitted to dog parks and doggie day care facilities. Living with an intact dog requires an owner to be ultra-responsible and even hypervigilant at times.

There are many good reasons to spay or neuter your dog and to do it sooner rather than later. However, there is also compelling evidence that delaying surgery may confer some health benefits to a large breed dog that will become an athlete, with a vigilant owner. Ultimately, this is a discussion that you should have with your veterinarian. Make sure you discuss the health benefits to your dog as well as the impact on your lifestyle that living with an intact dog may bring. Then you can make the best and most informed decision for you, your family and your dog.

Lori Teller, DVM is a graduate of Texas A&M College of Veterinary Medicine and lives in Houston, Texas. She practices at Meyerland Animal Clinic.