Spaying your dog is the best way to ensure that she will not have puppies, but there are many additional benefits to having a spayed dog, both for health reasons and for convenience. The surgery removes the influence of various hormones, which will change the behaviour of your own dog and others around it. During the twice-yearly heat cycles of an un-spayed dog, male dogs will be drawn to your dog during walks or in the yard, and the risk of unwanted pregnancies, fights, and disease spread will increase. For indoor dogs, it is additionally messy and inconvenient with bloody fluids dripping around the house.
According to studies, spaying increases life expectancy by 25%, as it decreases the risk of many types of cancer. Obviously, the risk of uterine and ovarian cancer is completely removed, but additionally there is a marked decrease in the incidence of mammary tumours (breast cancer), which is a very common tumour in non-spayed dogs. Transmissible vaginal tumours are relatively common in Kenya and are passed from dog to dog during mating. Spaying your dog will decrease the risk of this type of tumour as well. In addition to tumours, there are many other medical conditions that occur only in un-spayed dogs, such as pregnancy complications, pyometra and metritis (uterine infections) and ovarian cysts. Pyometra is a potentially life-threatening condition, where the uterus fills with pus after a heat cycle and the dog becomes very ill and often requires emergency surgery. Spaying usually has some effect on behaviour as well. Spayed dogs are less likely to roam and thus get into accidents or risk catching diseases. Generally, they are less aggressive.
There is no exact rule on the best age for surgery. There are many factors to consider, including the size of your dog and your lifestyle. From a medical point of view, a dog could safely be spayed as early as at the age of 2 months, but this is rarely recommended. First of all, the surgery has to be done in a clinic setting, and no matter how sanitary and clean the clinic is the risk of catching serious viral diseases is a very real one until the full course of vaccinations has been given at the age of 4-5 months. Secondly, if the surgery is done before the dog is fully grown, it can potentially disrupt the bone and joint growth of your dog, causing problems later in life. Especially in large breed dogs, early surgery might predispose them to a variety of hip, elbow and knee problems. Performing the surgery at around the age of 6 months is generally considered a good compromise, but with very large breeds it might be worth waiting until the dog is fully grown at around 1 year of age. Spaying can be done much later in life as well, which will still protect the dog from most hormone-related diseases. However, the risk of mammary tumours increases the later the dog is spayed. For a maximum benefit of reducing the risk of this very common type of cancer, the surgery should be done at around the age of 6 months.
Article by: Dr. Laura Wessman