Why Spaying & Neutering Your Dog or Cat Matters: A Simple, Science-Based Guide for New Pet Owner

Getting a new dog or cat is exciting—but it also comes with important health decisions. One of the biggest choices you’ll make early on is whether to spay or neuter your pet. Most people know these surgeries help prevent unwanted litters and babies, but their benefits go far beyond that. They can improve your pet’s health, reduce behaviour challenges, and even prevent life-threatening conditions later in life.

This guide breaks everything down in an easy, beginner-friendly way so you can feel confident in your decision.

Understanding Male and Female Pets: What Really Happens as They Grow Up

Before talking about surgery, it helps to know what male and female pets go through as they mature. Their hormones don’t just affect reproduction—they also influence behaviour, cleanliness, safety, and long-term health.

Female Pets: Heat Cycles and Unexpected Changes

Female dogs and cats experience repeated heat cycles throughout their lives, which can lead to dramatic and often surprising behaviours.

Female cats are what veterinarians call opportunistic breeders. They can go into heat simply because a male cat walked through your yard, a stray sprayed near your porch, an intact male lives in your home, or longer daylight hours triggered their hormones. Indoor cats can cycle repeatedly, showing loud yowling, rolling, restlessness, intense affection-seeking, escape attempts, and urine marking.

Female dogs usually go into heat twice a year. Owners often notice spotting or bleeding, swelling, restlessness, strong

smells that attract male dogs to the property, and an increased risk of accidental pregnancy. Heat cycles can be messy and stressful to manage, especially for new pet owners.

Male Pets: Marking, Roaming, and Hormone-Driven Behaviour

As male pets mature, testosterone becomes a major influence.

Male cats are more likely to roam far from home, fight with other cats, spray strong-smelling urine, vocalize loudly when females nearby are in heat, and try to escape through doors or windows. Male cat urine has a very strong scent that is difficult to remove from furniture or floors.

Male dogs may begin marking around the home, mounting or humping, reacting to other male dogs, becoming easily distracted during training, or trying to escape fenced yards when a female dog is in heat nearby. Intact males also face increased risks of urinary and prostate problems as they age.

Why Spaying Helps (Females)

Spaying removes the ovaries and usually the uterus. It protects female pets from several serious medical conditions and eliminates heat-related behaviours.

Health Benefits

Spaying prevents pyometra, a dangerous uterine infection common in unspayed females. Pyometra affects up to 25% of unspayed female dogs and is also seen in older unspayed cats. It typically requires emergency surgery. Spaying also dramatically reduces the risk of mammary cancer—spaying before the first heat lowers the lifetime risk by over 90% in cats. It eliminates ovarian and uterine cancers entirely and stops repeated heat cycles, making life quieter, cleaner, and safer for your pet.

Behavioural Benefits

Spaying eliminates yowling, pacing, restlessness, escape attempts, and unwanted attention from male animals. It also prevents the stress, blood spotting, and hormonal changes associated with heat cycles.

Why Neutering Helps (Males)

Neutering removes the testicles and lowers testosterone levels. This reduces hormone-driven behaviours and several medical risks.

Health Benefits

Neutering prevents testicular cancer and significantly reduces prostate enlargement, which affects most unneutered older male dogs and can cause painful urination or infections. It also decreases the risk of prostate infections and hormone-related tumors. Neutering lowers the risk of traumatic injuries in male cats, who often roam or fight when intact.

Bladder Stones and Urinary Issues in Male Pets

Male pets have narrower urethras, making urinary problems more dangerous. Intact male dogs have a higher risk of developing calcium oxalate bladder stones, which cause pain, straining, blood in the urine, infections, and sometimes require surgery. Prostate enlargement in older unneutered dogs can compress the urethra, making it difficult to urinate.

Intact male cats have a higher chance of urinary blockages, especially if stressed or dehydrated. A blockage in a male cat is a life-threatening emergency. Hormone-driven behaviours such as roaming, fighting, and spraying can also increase urinary inflammation and infections.

Behavioural Benefits

Neutering reduces marking, spraying, roaming, mounting, and aggression toward other males. It also helps with focus during training and lowers the risk of outdoor injuries.

Worried About Surgery? Here’s How to Reduce Risks and Help Your Pet Feel Safe

It’s normal to be nervous about anesthesia and surgery. Veterinary teams take multiple steps to make the experience safe and comfortable, and there are things you can do to help.

Pre-Anesthetic Blood Work

Blood work before surgery checks kidney and liver function, hydration, blood sugar, and red and white blood cell levels. These tests help ensure your pet can safely handle anesthesia. If anything is abnormal, the surgical plan can be adjusted, or the procedure can be postponed until your pet is stable.

Calming Pets Who Get Stressed at the Clinic

Some dogs and cats become anxious just walking into the building. Pre-visit calming medication can be given at home to reduce stress and make the entire process smoother. Let us know if your pet has shown fear, anxiety, or reactivity—we can provide medication, schedule quieter times, or use gentle handling strategies to help.

Day-of-Surgery Monitoring

During the procedure, your pet is continuously monitored for heart rate, breathing, oxygen levels, and temperature. Pain control is given before, during, and after surgery, and anesthesia is tailored to your pet’s age, breed, and health.

Post-Surgical Care at Home

Following the home-care instructions is one of the biggest factors in a smooth recovery. Keep your pet quiet and rested for 10 to 14 days, prevent running and jumping, use an e-collar/cone, give pain medications as prescribed, and check the incision daily. A calm environment and preventing licking or chewing help ensure proper healing.

The Takeaway

Spaying and neutering are simple, routine surgeries with decades of research behind them. They help pets live longer, healthier lives with fewer medical problems, fewer behaviour challenges, and far less risk of emergencies. For new pet owners, these surgeries also remove much of the stress and mess associated with hormones and heat cycles.

If you have questions about your dog or cat, or you’re ready to book their procedure, the team at Main Street Markham Animal Clinic is here to help every step of the way.