Back in the day, veterinarians typically recommended spaying a female dog at about 6 months of age—before her anticipated first heat cycle. Spaying before the first heat avoided the mess of the cycle and the risk of pregnancy. Today, the answer is not so simple: the best time to spay a dog can vary by breed, size and individual health risks. This blogpost explains why veterinarians’ recommendations have changed and which factors now shape the decision.
Preventing Unwanted Puppies
In the early days of the Schwarzman Animal Medical Center, then known as the Women’s League for Animals, dog overpopulation was a significant problem the organization was struggling to address. Spaying dogs at six months of age was a sure fire way to prevent unwanted litters: most female dogs had not yet gone into heat and could not yet become pregnant. This recommendation helped reduce the number of homeless dogs. Spaying a young dog is also generally easier than spaying an older or heavier dog. Reducing the stray population benefited human health, too: canine rabies vaccines were not yet widely available, and human exposure to canine rabies was more common than it is today.
Spaying Prevents Several Serious Diseases
Spaying before the first heat cycle offers health benefits beyond preventing pregnancy. Most notably, it is associated with a lower risk of mammary gland cancer risk. Data suggests early spaying decreases that risk to 1 in 100,000.
But age is not the whole story: breed matters, too. Cocker spaniels and English springer spaniels may have an increased risk of mammary gland cancer, so their owners should discuss the potential benefits of early spaying with their veterinarian.
Spaying at any age also eliminates the risk of ovarian cancer and prevents a potentially deadly infection called pyometra. Pyometra is a bacterial infection of the uterus that occurs in about 1 in 5 unspayed dogs older than 10. Because the infection is internal, owners may not recognize it until the uterus is filled with pus and emergency surgery is needed to save the dog’s life.
Why Spaying Later May Protect Some Dogs
Here is where the information gets even more confusing: the health effects of spaying depend not only on age, but also on breed. Generally speaking, small-breed dogs are less likely than large-breed dogs to develop urinary leakage or joint problems, such a cruciate ligament rupture, after early spaying. Yet not every large breed shows an increased risk of joint disease; collies and Doberman pinschers are two examples. Doberman pinschers spayed early, however, may have an increased risk of urinary incontinence. In other words, there is no single best age to spay every dog.
How to Decide When to Spay Your Dog
Your veterinarian should be your first source of information about when to spay your dog. The decision should account for your dog’s breed, expected adult size, age, lifestyle and individual health risks.
Some folks also like to do a bit of preparation beforehand. If you have a purebred dog, the American Kennel Club website is one place to review health concerns associated with the breed. Each AKC breed page includes information about health concerns for that breed. Knowing those breed-related risks can help you ask the right questions and make an informed decision with your veterinarian.
For readers comfortable with scientific literature, two studies offer additional guidance: one examines spay and neuter timing in purebred dogs, and the other looks at mixed-breed dogs.
The bottom line: The best time to spay a dog is no longer a one-size-fits-all answer. Talk with your veterinarian about the timing that best balances pregnancy prevention with your dog’s breed-, size- and age-related health risks.
Tags:
cancer, doberman pinscher, dogs, english springer spaniels, mixed breed dogs, pyometra, spay, spaying,
