By David Brooks MRCVS of Pet Insurance Expert.

As a dog owner it is sometimes difficult to make decisions about what is right for your pet, especially with many veterinarians and pet professionals having at times conflicting views on the pros and cons of neutering. This article aims to dispel some of the myths surrounding neutering and enable you to make an informed choice on this important issue.

Neutering a male is a procedure known as castration. It involves complete removal of the testes via a small surgical incision between the penis and the scrotum. Dogs do not have vasectomies like humans do as they are usually neutered for reasons other than birth control. There have been several occasions where owners have been unaware of this fact until the operation has been done, causing resentment in some cases. The pros and cons of castration will be discussed shortly.

Neutering a female is a procedure known as spaying. It usually involves an ovariohysterectomy, removal of the ovaries and uterus via a surgical incision over the belly button. Note how this differs with the equivalent human procedure, a hysterectomy, where only the uterus is removed. Again this is because female dogs are neutered for other reasons in addition to birth control where removal of the ovaries is beneficial.

Why should I neuter my dog?

For males, the reasons in favor of castration are:

1. Birth control. If you also own a bitch that has not been spayed, this will prevent unwanted pregnancies.
2. Stopping territorial behavior such as urine marking.
3. Stopping sexual behavior such as masturbation (humping cushions, teddies etc).
4. Reducing dominance aggression.
5. Eliminating the possibility of testicular cancer later in life.
6. Reducing the likelihood of prostate disease later in life.

The arguments against castration in male dogs are:

1. Weight gain. Castration usually leads to undesirable weight gain, which in itself can cause or exacerbate diabetes, heart disease and arthritis. Castrated dogs should have their food intake decreased by 20% to accommodate this change and prevent obesity.
2. The anesthetic risk. With every general anesthetic there is a risk, but in a young fit dog that risk is very, very low.
3. Other potential complications. These are very rare and usually easily resolved and include infection, bleeding into the scrotum and herniation.
4. The cost. This will vary hugely between clinics, and depend upon the size of the dog.

For females, the reasons in favor of spaying are:

1. Birth control. Unwanted pregnancies are a hassle, if they occur you have the responsibility of terminating the pregnancy (this can be done via a simple injection soon after mating), paying for any complications with the birth (Caesarian sections are expensive) or finding loving homes for the puppies.
2. Stopping the bitch from having seasons during which blood is dripped from the vulva over the floor in your home.
3. Stopping erratic behavior associated with being on heat.
4. Decreasing the likelihood of breast cancer later in life.
5. Eliminating the risk of developing a pyometra, a life threatening infection of the uterus.
6. Eliminating the risk of ovarian or uterine cancer.

The argument against spaying in females are:

1. Weight gain. Spaying usually leads to undesirable weight gain, which in itself can cause or exacerbate diabetes, heart disease and arthritis. Spayed dogs should have their food intake decreased by 20% to accommodate this change and prevent obesity.
2. The anesthetic risk. With every general anesthetic there is a risk, but in a young fit bitch that risk is very, very low.
3. Other potential complications. There include infection, breakdown of the abdominal wound and internal bleeding. These are very rare and usually easy to resolve.
4. Spayed bitches are more likely to suffer from urinary incontinence in old age. However, this type of incontinence is easily controlled by medication if it occurs.
5. The cost. This will vary hugely between clinics, and depend upon the size of the bitch.

When should I neuter my dog?

The answer is it varies with the breed. For male dogs, they should be approaching skeletal maturity, i.e. their bones should be almost fully grown. In small breed dogs such as terriers, this can be around 6 months of age but larger breeds mature more slowly, and should be castrated at nearer 1 year old. If the reason for castration is to alter the behavior of the dog, then it must be done at the earliest opportunity so that the behavior does not get engrained.

Bitches should be spayed just before or 3 months after their first season. Doing it early in this fashion minimizes the chances of the bitch getting mammary tumors later in life. Leaving it until the bitch has had 2 seasons means you are missing this window, and the advantage is lost. As with male dogs, small breed bitches mature more quickly than larger breed bitches and so will have their first season earlier, sometimes as early as 6-7 months old. There is no significant difference in before or after the season, but it must be the first season.

It is a bad idea to spay a bitch during a season as the uterus is swollen with a larger blood supply then, so the risk of bleeding is increased. Hence vets like to leave it until 3 months after the season, when the uterus has shrunk again and the surgery is easier and safer. It is also a false myth that it is healthier for a bitch to let her have a litter before spaying her. This simply means you miss your optimal spaying window and lose the ability to prevent breast cancer later in life.

How do I get my dog neutered?

Very easily. Both castration and spaying are routine operations performed by virtually all veterinary clinics, often on a daily basis. Before booking your dog in to be neutered your vet will need to do a quick clinical examination to check your dog is ready for the operation. This will usually involve just listening to the heart and lungs to confirm there is no underlying disease that might jeopardize an anesthetic. In male dogs, the testes are felt to make sure they have descended properly. If they have not, a more complex procedure might be necessary to remove them. In bitches, the mammary glands are often felt to check she is not lactating as this can complicate the surgery.

Once booked in, your vet will usually ask you to starve your dog from midnight the night before the operation, to ensure he/she has an empty stomach at the time of surgery. The dog is then dropped off at the clinic and usually collected later on that day. Dogs having routine neutering rarely have to stay at the clinic overnight, they usually go home with an Elizabethan collar to protect their stitches and a wagging tail!

David Brooks MRCVS is part of the veterinarian team at Pet Insurance Expert, the most comprehensive resource on pet insurance in the UK. Learn about the different pet insurance options and find the best pet insurance for your pet.