Veterinarians routinely recommend that companion pets should be spayed or neutered, and they have many good reasons for doing so. These elective procedures can reduce certain health problems and prevent pets from developing troublesome behaviors related to reproduction. Sterilization procedures are also an important step in reducing pet overpopulation, which leads to millions of pets being euthanized each year. Our Memorial Animal Hospital team shares why you should have your pet spayed or neutered, and the optimal age your pet should be when they have this surgery to reap this procedure’s health benefits.

#1: Reduce reproductive cancer and other health risks in pets

Intact female pets have a high risk for mammary (i.e., breast) cancer, which is nearly always malignant and fatal in cats and in approximately half of dogs who develop the disease. Having your female pet spayed before their first heat cycle greatly decreases their mammary cancer risk, with the risk gradually increasing with each subsequent heat cycle. During the spay procedure, your veterinarian removes your female pet’s ovaries and uterus, eliminating the internal reproductive cancer risk. 

Male pets’ reproductive cancer risk is lower than that of female pets, but still present. By removing a male pet’s testes, a veterinarian eliminates this cancer risk and greatly reduces the incidence of prostate enlargement later in life. Studies show that spayed or neutered pets live longer than their intact counterparts. The reasons why are complex and not entirely clear, but study after study has shown this to be true.

#2: Reduce undesirable pet behaviors

Intact pets may exhibit reproductive-related behaviors that make them difficult to live with or that put them at risk for injuries. An intact female cat yowls and behaves oddly as they come into heat. An intact male may consistently urine mark indoor and outdoor territory, and fight with another male over a female’s attention. Female dogs cycle twice a year, which can be a messy process. Male dogs have a strong desire to roam, and many are hit by cars when they escape their home or yard. 

A spay or neuter procedure reduces the hormones that cause a pet to exhibit undesirable reproductive behaviors, making them more agreeable companions. Note that while an intact pet may be aggressive to other pets at certain times, having them spayed or neutered does not generally solve aggression toward humans or other unrelated behavior problems.

#3: Avoid contributing to the pet overpopulation

Spaying and neutering reduce pet overpopulation. Between 3 and 5 million unwanted, homeless pets overwhelm U.S. shelters each year, and sadly, 1.5 to 2 million of these pets are euthanized annually. Don’t believe the false narrative that allowing your female pet to have a single litter before being spayed is beneficial to their health. Studies have proven no benefit to this practice. Some neighborhoods have problems with feral (i.e., wild) cat colonies, which are generally self-sustaining but can harm the area’s wildlife populations. Feral cats often carry and transmit infectious diseases to owned pets. 

#4: Avoid costly emergency veterinary surgery

Older, intact female pets are at risk for the deadly uterine infection pyometra. This infection’s bacteria can leak into the abdomen or bloodstream, and most pets with untreated pyometra die. Emergency surgery is the only option to save an affected female pet’s life, costing her owner several thousands of dollars, which is much more than a preventive spay surgery’s cost, which is usually less than $1,000.

Is spaying or neutering my pet worth the risk?

Current anesthetic protocols and monitoring techniques ensure that a healthy pet undergoing anesthesia has an extremely low complication risk. Presurgical blood tests and a complete physical examination help ensure your pet is healthy enough to undergo surgery. Complications, such as infection or incision problems, occur infrequently, with most being easy for your veterinarian to manage. In most cases, a pet’s risks of developing reproductive cancer and other health problems outweigh the minor risks associated with these procedures.

What is the optimal age at which my pet should be spayed or neutered?

Optimal spay or neuter timing is of major interest among veterinary professionals, with multiple studies having investigated the effects of the surgery’s timing based on a pet’s breed and size. In cats, the recommendations are clear: Spaying or neutering performed before the pet is 5 months of age is the optimal time and does not increase your whiskered pal’s risks for any future health problems. 

In dogs, reproductive surgery timing recommendations are more complex. To reduce health risks, male and female dogs expected to weigh less than 45 pounds should be spayed or neutered when they are between 5 and 6 months of age. However, studies show that large-breed dogs may have an increased risk for several nonreproductive cancers, including osteosarcoma and hemangiosarcoma, and orthopedic problems, including hip dysplasia and knee ligament degeneration, when they are spayed or neutered at a young age. Some studies also indicate that female dogs are more likely to develop urinary incontinence if spayed at a young age. 

Deciding on the optimal time to spay or neuter your large-breed dog will require a thorough discussion of the risks and benefits with our Memorial Animal Hospital team. We typically recommend that large-breed male dogs be neutered after they reach their full, expected size, between 9 and 15 months. For large-breed female dogs, we consider their risks for mammary cancer, incontinence, other cancers, and orthopedic diseases to make an informed case-by-case recommendation. More research is expected to come to the fore in the near future to help clarify this issue and provide further guidance.

Having your pet spayed or neutered is a low-risk way to help ensure they avoid certain health problems as they age. However, the decision to have your pet undergo this surgery is ultimately between you and your Memorial Animal Hospital veterinarian. For recommendations on the optimal time to schedule your pet’s reproductive procedure and to discuss your four-legged friend’s surgery, anesthesia, and postoperative recovery, call our Memorial Animal Hospital team.