Making the decision to spay or neuter your pet or not requires a lot of thought. When you spay or neuter, you are removing the female’s ovaries and uterus and the male’s testicles. Unspayed or neutered cats can have their first heat as early as 4 months and dogs at 5-6 months. Cats can have 3 litters and dogs 2 litters per year.

There are pros and cons to both. The media has informed us of the plight of homeless pets in our country. There are 7 puppies and kittens born in the US for each 1 human. There are as many as 6-8 million homeless pets in the US per year. As many as 30-50% of these animals are euthanized due to a lack of people adopting them. Shelters are not just home to feral pets but to litters of unwanted pets or pets that people could not care for. This is a significant pro for why we should spay or neuter our dogs and cats.

Also on the pro side to spaying or neutering, studies have shown that spayed or neutered pets live longer; as much as 18% longer for males and 23% longer for females. This is due to the fact that these animals have reduced risk from health issues or aberrant behaviors.

Some of the health issues related to not spaying or neutering are an increased risk of life threatening conditions such as females having mammary infections or cancer including mammary, ovarian and uterine cancers. In males, there is increased risk of testicular and prostate infections and cancer. Mammary gland tumors in female dogs and cats who are not spayed are more common in older females. Female dogs and cats that are spayed before the first heat have almost no chance of developing mammary cancer later in life. Spaying after the first heat increases the risk to 7% and spaying after the second heat increases the risk to 25%. Cancer of the uterus, ovaries and testicles is twice as common in dogs than in cats. But by removing these sexual organs, the chance for infections and cancer in these areas is reduced to none. Also for females, having a litter can also be physically dangerous and stressful to them.

In the behavioral realm, unneutered males can become more aggressive which can be a problem for children and other animals. They tend to become frustrated in their search for a mate and have a tendency to roam more. This puts them in potential danger from car accidents or fights with other animals, which can cause serious injuries. Males will also do more urine marking. Some females also urine mark or become irritable in heat. Pets may exhibit more dominance related behavior such as excessive barking in dogs and howling in cats. Spayed or neutered pets are often more relaxed and less prone to aggressive behaviors or roaming. They do not have to get fat although they can have a decrease in metabolism. The pet owner will need to monitor food intake and nutrition and give their pet the opportunity for exercize. Spaying or neutering does not change the pet’s basic personality, like being protective, which is formed more by genetics and the environment. Animals do not recognize their sexual identity so there will not be an identity crisis if you remove their sexual organs. However, in all cases, pets require basic behavior training with or without spaying or neutering surgery.

Then there is the cost and population crisis. It is not cheap to care for a litter of puppies or kittens. By bringing more litters into the world, it decreases the number of adoptions from shelters and leads to more euthanization of unadopted animals. There is a relatively low cost to spaying or neutering a pet, especially at clinics that specialize in this. The dog or cat that has not been spayed or neutered may roam more and end up in an accident or fight that requires huge veterinary bills due to injuries.

On the con side of whether to neuter or spay, there are also behavior, health and cost issues. Some feel that females need their estrogen and oxytocin hormones to keep them calm and less anxious. It is felt that without these hormones, they can become more aggressive.

Some studies have shown that spayed females tend to develop more frequent urinary tract infections. As many as 5-20% of the spayed females have an increased incidence of spay incontinence. The risk is even higher for overweight dogs. Dogs spayed or neutered before reaching adult size may grow a little taller than if not surgically altered. In dogs prone to certain conditions, there can be an increase in risk of getting transitional cell carcinoma of the bladder, osteosarcoma and hemangiosarcoma. There is also a risk of increased hypothyroidism, knee and hip problems. There is an increased risk for endocrine issues due to hormone imbalance. These can lead to Cushing’s disease and other adrenal diseases. Endocrine issues can be difficult and involve costly tests to diagnose. Many studies have shown changes in appetite, metabolism and weight gain do occur, especially in animals that lead a more sedentary existence. However all studies say that monitoring the diet can prevent weight gain.

The majority of the articles researched conclude with the fact that the benefits of spaying or neutering cats and dogs far outweigh those of not spaying or neutering. It is an individual decision but soliciting the advice of your veterinarian is also important. They can advise you based on your particular pet’s breed and predisposition to behavioral and health issues.

* Editors note: Tails Untold is presenting these facts that have been taken from numerous articles on the subject in order for readers to be informed in their choices. It was not written to question the idea of whether to spay or neuter or not. However, the Tails Untold Company does donate proceeds from their books to animal shelters and causes that protect animals.