Please remember that humane societies and animal shelters are overrun with unwanted cats, dogs, kittens, and puppies. Spaying or neutering your pet decreases the number of needless deaths every year. There are also large populations of feral cats as well as stray dogs - these animals are usually unvaccinated and contribute to the spread of disease.


"Spaying" is the common term used to describe the surgical procedure known scientifically as an ovariohysterectomy.  In this procedure, the ovaries and uterus are removed completely in order to sterilize a female dog or cat.  "Neutering" or "castration" are the common terms describing the surgical procedure known as orchidectomy.  In this procedure, both testicles are removed to sterilize a male dog or cat.

At the Mississippi Mills Animal Hospital we recommend spaying your pet between 6 and 8 months of age; the veterinarian may discuss waiting until 1 year of age in giant breed male dogs, however.  The surgery is a day procedure so your pet will go home the same day.  Dogs and cats undergoing either a spay or a neuter procedure get medication for pain during their surgery and are carefully monitored afterwards to make sure their pain is adequately controlled. Pain control medication is dispensed for dog spays and neuters as well as cat spays to ensure your pet is comfortable at home post-operatively.  Although most pets appear to recover very quickly from these procedures, 10-14 days of exercise restriction is still very important to the healing process.

What are the advantages of spaying in the female dog?

  • Prevention of "heat" or estrus.
  • When in "heat" the female experiences an urge to escape in order to find a mate. This unwanted and dangerous behaviour is eliminated in a spayed female.
  • Elimination of the hormone fluctuations that cause false pregnancy following the "heat cycle".
  • Prevention of uterine infection known as pyometra.
  • Prevention of breast/mammary cancer. Dogs spayed before their first "heat" have less than 0.5% chance of developing mammary cancer.
  • Elimination of the risk of uterine and ovarian cancer.

What are the advantages of neutering my male dog?

  • Reduces the risk of benign prostatic hyperplasia and prostatitis.
  • Reduces the risk of hormone-related diseases such as perianal adenoma.
  • Eliminates the risk of testicular cancer, the second most common cancer in intact male dogs.
  • Removes sexual urges which will usually decrease roaming behaviours.
  • Reduces certain types of aggression.

Why should I have my female cat spayed?

  • Prevention of "heat" or estrus.
  • Elimination of the risk of ovarian and uterine cancers.
  • Prevention of breast/mammary cancer. Mammary cancer is the number one type of cancer diagnosed in intact or un-spayed female cats. If your cat is spayed before her first "heat" cycle there is less than 0.5% chance that she will develop breast cancer. With every subsequent heat cycle, the risk of developing breast cancer increases; after about 2½ years of age, ovariohysterectomy offers no protective benefit against developing breast cancer.
  • Prevention of uterine infection known as pyometra.

Why should I have my male cat neutered?

  • Intact male cats exhibit territorial marking behaviour in which they spray very strong-smelling urine on surfaces, sometimes even inside the house.
  • As he ages, the tomcat will want to escape the house to enlarge his territory. He can end up injured in fights with other cats over territory. Diseases such as FIV and FeLV, which cause immunosuppression and AIDS-like symptoms, are often spread this way. The longer a tomcat sprays and fights, the less likely neutering will stop these behaviours.