Neutering Fact Sheet for Dogs

1. Introduction

Neutering is a surgical operation that will leave your dog unable to have puppies, eliminating the risk of testicular, uterine, and some breast tumor diseases. It will also help prevent unwanted litters, roaming, and inappropriate behavior associated with mating hormones. This fact sheet has been developed to help prospective dog owners consider neutering and the risks, possible complications, and aftercare involved.

A full anaesthetic is needed to neuter a dog, and the operation itself usually takes 30 minutes to an hour. Dogs are admitted for the operation in the morning and go home the same day. After the operation, the dog must be kept at home, calm and quiet, for about a week (M. Belanger et al., 2017). There is no need for a cone collar or head bandage unless the dog licks its stitches. Normally, the stitches come out after ten to fourteen days. Bleeding is uncommon but call your vet immediately if it happens.

On the day of neutering, dogs are starved overnight and given nothing but water for the twelve hours leading up to the operation. When the dog arrives at the vets, a vet nurse will love them and check their details. The dog is then weighed, then taken into the operating room, where an intravenous catheter is placed in their leg and anaesthetic drugs are administered. Once the dog is asleep, an endotracheal tube is placed in their throat, and nitrous oxide and oxygen gas are administered during surgery. Dogs are monitored closely during surgery, including a special monitor that detects heart problems. Dogs wake up an hour or two after surgery and are taken back to recover in comfortable bedding with a vet nurse watching over them (M. Oberbauer et al., 2019).

2. Benefits of Neutering

The Benefits of Neutering section provides an overview of the benefits of neutering dogs. There are two main groups of benefits: population control and health benefits. Population control refers to reduced unwanted litters and better population control. Health benefits include reduced risk of certain cancers, tumours, pyometras, and infections. These benefits all provide an overall net good not only for the dog but also the pet population and public health.

Population Control

A primary intention of neutering is the prevention of unwanted litters (R. Urfer & Kaeberlein, 2019). The sheer quantity of seasonal heats means that it can be extremely easy for uninvited suitors to successfully breed with a female. A concerning occurrence of puppies is detrimental to both the individual dog and the general population, with unwanted puppies leading to abandonment, shelter overcrowding, and euthanasia (M. Oberbauer et al., 2019). Unwanted puppies are difficult as they require significant time and economic resource investment to raise. The entire canine population suffers as a result of bad ownership practices, puppy mills and shady breeding operations, and poor training and socialization. This is exacerbated when adolescent and adult dogs are relinquished: abandoned dogs often fare poorly and form a feral population that can be dangerous to both people and pets, and cause further population issues through uncontrolled reproduction.

2.1. Population Control

Gonadectomy, or spaying/neutering, is the most common surgical procedure performed on pet dogs (M. Oberbauer et al., 2019). This procedure is undertaken by pet owners who want to control reproduction, eliminate undesirable behavioral characteristics, and reduce relinquishments of dogs to shelters. A recent survey of American pet owners revealed that most desired breeding restrictions on their dogs. Past studies suggest that gonadectomy generally reduces similar behavioral characteristics across the sexes and breeds, but there are report inconsistencies. Surveys have helped researchers understand behavioral differences, aggression, and relinquishments among neutered dogs, but little has been done to evaluate health conditions associated with the age at which a pet dog is neutered. Pet overpopulation is a significant and growing problem in the U.S. Too many dogs are left homeless each year, while only a portion find new homes. Canine overpopulation in the U.S. results in the death of millions of unwanted, abandoned, and abused dogs, as well as the suffering of their mothers and long-term effects on the environment. Age of gonadectomy and method of relinquishment are correlated. Early neutering is associated with relinquishment (R. Urfer & Kaeberlein, 2019). Gonadectomy is one way to help control population pressure on unwanted puppies.

2.2. Health Benefits

In addition to preventing unwanted litters, neutering can have numerous health benefits for your dog that can make their life longer and healthier. Males dogs that are neutered are less likely to develop testicular cancer or prostate problems. Female dogs that are spayed have a decreased risk of developing breast cancer, especially if they are spayed before their first heat cycle (M. Oberbauer et al., 2019). Spaying also eliminates the possibility of uterine infections, which can be fatal in very short time periods (M. Belanger et al., 2017).

3. When to Neuter

There is a question that needs to be answered in order to make a decision about neutering: “(M. Oberbauer et al., 2019)” A common concept is to neuter a male dog before it reaches puberty, at about 6 months of age. A male dog that is neutered at this age will not have learned any of the sexual behaviors associated with an intact male dog, such as mounting, roaming, and excessive marking. However, a male dog does not need to necessarily be neutered until he has already demonstrated these behaviors. Whether or not to neuter a dog at this age, is a choice that ultimately lies with the owner. Caretakers should be educated about the potential disadvantages and advantages associated with their current plan and/or the alternative options.

It is common for behavior to influence whether concrete plans are made and, if so, when they will occur. In particular, sexual behaviors are an aspect of a dog that can be extremely undesirable. A consideration that often accompanies the discussion of the impacts of neutering on behavior is the question: “(M. Oberbauer et al., 2019)” Aspects that must be understood in order to appreciate the choice of age for neutering include when the physical and sexual maturity of a male dog occurs, and how these factors relate to impending undesired behaviors in the individual dog. For example, if a pet owner has a mid-sized intact male dog that is presently 4 months old and not yet demonstrating the excessive mounting, roaming, or marking behaviors that often accompany sexual maturity, then there is an interest in knowing when these behaviors will likely begin. Factors that can influence this timing include the sex and environment of the dog, in addition to the breed of the dog taking into consideration its size at maturity (M. Oberbauer et al., 2019).

3.1. Age Considerations

Some considerations for choosing the appropriate age to neuter your dog. These considerations are mainly based on the age of your dog and the research on what the potential effects of timing may be. Understanding these considerations regarding age may help you to decide when to have your dog neutered. You should consider discussing with your veterinarian what the potential effects of timing are on the health and development of your dog.

Puppies should be at least eight weeks old prior to neutering surgery (M. Oberbauer et al., 2019). If your dog is under eight weeks old at the time of surgery, the surgery will be postponed. Puppies over eight weeks old may be neutered during any routine spay or neuter clinic. Most, if not all, municipal spay/neuter clinics do not accept dogs over six months of age. If your dog weighs over 110 lbs and is under six months old, the surgery will be postponed until the dog is six months old or 110 lbs, whichever comes first. If your dog is more than six months old or more than 110 lbs at the time of surgery, the surgery should continue as planned. However, it is often the case that surgeons will not perform surgery on dogs over six months old because they may be deemed unmanageable (Zlotnick et al., 2019).

3.2. Behavioral Considerations

Describing behaviors that should be considered, this section notes that aggression is often a major reason dogs are surrendered to shelters. Therefore, those adopting a dog will likely want to know about social behavior and aggression. Behavior cannot be taken into consideration in a binary way, as there is a spectrum of effects, positive and negative, that must be considered with potential diverse outcomes (Kriese et al., 2022). Unfortunately, it appears at this time that there are few or no studies that really characterize the effects of neutering on behavior. There are studies looking for associations between the status of neutering and behavior, and this may serve to illuminate some of the issues. Still, neither this review nor the referenced studies provide a clear-cut consideration of the optimal age for neutering. Neo males and females tend to be more dominant than their peers and this difference was suggested to be a by-product of early hormonal imbalance (M. Belanger et al., 2017). This raises the question of whether the age that animals are castrated influences their level of dominance and social success in dog-on-dog interactions. Neuroanatomical studies suggest that if males are castrated before puberty, they do not develop certain neural structures considered requisite for the expression of mature aggression. Dogs castrated before 6 months of age are less likely to be aggressive at maturity than those not castrated until after six months of age. Consequently, the effects of neutering on social behavior and aggression might differ depending on the age of neutering. Studies have shown that castrated dogs are less aggressive towards family members than intact dogs, but are more likely to behave aggressively towards unknown people.

4. Neutering Procedure

The technical term for neutering male dogs is castration. This involves both testicles being removed. The veterinary team will take the dog away for the procedure and put them under a general anesthesia, which means that they will be asleep throughout the surgery and unable to feel pain. It is carried out in a sterile operating theater, which the dog will be taken to. While the dog is under anesthetic, they are placed safely on a table and attached to equipment that monitors breathing and heart rate. The dog is shaved around the area where the surgery is taking place to minimize the risk of infection. A soft tube is placed in the dog’s windpipe, until they are breathing normally again. If the dog is a smaller breed, the vet may choose to carry out the procedure with the assistance of a small handheld instrument known as a 'laparoscope.' This can help speed up recovery compared to traditional surgery (M. Oberbauer et al., 2019).

Once the dog is under general anesthesia, a nurse provides oxygen to breathe and displays their breathing and heart rate on a monitor to ensure they are safe during the surgery (M. Belanger et al., 2017). The vet then makes a small incision (approx 1cm) in the middle of the dog’s abdomen, just below the belly button (umbilicus). The canine testicles are located in the abdomen, and the vet puts the camera inside. Gas is pumped in and swollen up to allow the vet to see clearly. The vet then uses the instrument to make a small hole into each of the sacs that hold the testicles (the vaginal process) and two small holes where each blood vessel goes to the testicles. A stitch is placed tightly around the blood vessel and this is cut, removing the testicle. This harm is repeated on the opposite side. The vet then checks that there is no further bleeding and blows out the gas, allowing the dog’s belly to shrink back down to normal size. All of these need just small stitches under the skin so there are no stitches to remove afterwards. Once the surgery is complete, the dog is moved into recovery, where the anesthetic is ‘turned off.’ In most cases, the dog will be out of the operating theater within an hour of starting the surgery.

4.1. Surgical Process

Pre-operative preparations

To ensure a successful surgery, several factors should be taken into consideration prior to the procedure. Firstly, it is crucial that at least 24 hours prior to surgery, the dog should not be fed food. The dog may be given water, however, this needs to be controlled, as excessive drinking may cause vomiting during the procedure. Note: Dogs that are less than four months old do not require fasting. Secondly, many dogs tend to shed excessive hair in periods of stress. In these cases, the dog's bedding area and surgery area should be cleaned before the procedure. Thirdly, it is important to collect pertinent information about the dog, such as medical history, previous illnesses, medications administered, and behavioral notes. In the case of brachycephalic breeds (Pugs etc.), it is recommended to consult with the vet to assess the risks of anesthesia. Finally, it is highly suggested to neuter non-pedigreed dogs, as this prevents inbreeding and ultimately saves families from economic and emotional burdens.

The surgical nerve blocks

Examine the dog carefully prior to surgery, checking major organs (heart, lungs, etc) to locate pre-existing health issues. Nerve blocks are very useful to eliminate pain from the surgical site. However, there are risks associated with nerve blocks and a vet's assistance is highly recommended during this step. Local anesthesia needs to be done with care, as over-anesthetizing may cause permanent nerve damage. There are advantages to nerve blocks (decreased quantity of anesthesia needed, attenuated adverse effects, positive effects on behavior after the procedure) and disadvantages (rigidness of the limb, inability to assess pain, etc.). Small breeds will receive a 0.1ml Bupivacaine block, medium will receive a 0.25ml Bupivacaine block, and large breeds will receive a 0.5ml Bupivacaine block.

The anesthetic agents

Check the bloodwork lab results to assess the state of the dog's major organs. Administer Ketamine and Diazepam by IV, observing the reaction of the dog carefully. If the behavioral response seems inappropriate, stop pushing the drugs and wake the dog up before it gets too deep of a sleep. Malicious dogs (especially males) could be a serious safety issue, however, they could be pre-treated with Acepromazine by injection or Tranquil Sit by pills prior to contacting them. With small breeds, it is important to keep the head elevated in order to avoid complications from hypoxia

Surgical site preparation

If the dog is a medium or large breed, and the dog is very aggressive or the vet has concerns about the behavior of the dog, he/she may need to either pre-anesthetize the dog, or muzzle the dog. When muzzling, the dog should lay on its side, so the muzzle should be applied in a position that does not obstruct breathing (the muzzle should be in front of the snout). Confining the head with a towel will keep the dog still. A muzzle should be removed immediately after the completion of the surgery, as it may provoke vomiting. However, returning the dog to its crate without a muzzle needs to be done with caution.

Surgical process

Sterilization of equipment and tools needs to be done carefully and thoroughly before the surgery to prevent any infection or post-surgery complications. Prepare a scalpel, needle holder, scissors (for suturing), various clamps, additional items (scissors, hemostat, retractors, forceps, laparotomy sponges), cotton pads, a large needle and a supply of catheters (Jugular and Cephalic). Neuter procedures for both sexes are very similar; however, castration of males may be done by an open or closed method, and surgery requires different tools. To maintain a sterile environment, only one person should scrub. Any breaks in sterility should be reported to the Preparation Officer, as a sterile environment must be kept throughout the entire surgery. Alternatively, any sterile object that falls on the floor should be discarded.

Post-operative care

if the procedure went smoothly, all records should be noted and filed properly. Update the daily surgery log, indicating the procedure, time the animal came in, time of surgery, any meds given (for example, Tramadol, Rimadyl, antibiotics, etc), and time of release. Indicate on the record if the animal had any prior medical conditions, allergies, etc. Fill the dog’s care sheet clearly, detailing its name, procedure, sex, age, weight, any meds given and time, and any special instructions (e.g. keep cone on at all times, etc.). The tattoo number should also be added to the care sheet and be logged in a separate tattoo record book.

4.2. Aftercare

The recovery phase after neutering is a very crucial time. It is important to ensure your pet is comfortable and looking after the wound to promote healing. The dog must remain at home for several days to recuperate from the operation (M. Belanger et al., 2017). You should observe the behaviour of your pet during the recovery phase. A certain amount of discomfort or pain can be anticipated and is quite normal. For particularly excitable or unhappy pets, the vet may have given you a sedative to calm your dog down. However, it is important to follow the veterinarian instructions to avoid any serious issues. After general anaesthesia, the pet should remain quiet for some time. A full recovery can take several hours in some cases. The operation site should be kept clean and dry, and check the wound on a regular basis, looking for any signs of inflammation such as swelling, redness or warmth (K. Dawson et al., 2019).

During the first few days, food can be offered in small amounts, and boiled rice with white fish or chicken may be given as this is fresher and easier to digest. Do not leave the pet alone for the first week due to the potential for running. On the seventh day, schedule a follow-up appointment with the veterinarian for suture removal. Up to this time, the pet must be kept calm, avoiding jumps, runs or games and must not be allowed to lick at the stitches or bandages as this could cause an infection. Depending on the pet’s habit, a blow-up collar can be useful.

5. Frequently Asked Questions

Neutering is the routine removal of the reproductive organs and is performed under general anaesthetic. The male’s testicles are removed, with a small incision made at the base of the scrotum. The incision is typically closed with stitches below the skin which dissolve in about 10-14 days. The female’s ovaries and uterus are removed, with an incision made on the side of the abdomen. The incision is often closed with stitches behind the skin that dissolve in 10-14 days or require removal. Your dog should be monitored at the veterinary clinic until fully awake from the anaesthetic, which usually takes a few hours. Once home, the owner is responsible for their dog’s post-surgery care and adherence to any specific instructions given by the veterinarian. Dogs can typically return to normal routines after 7-10 days.

What precautions should be taken after neutering? A dog’s activity level should be closely monitored and restricted to short on-lead walks for 7-14 days after surgery. Long walks, running, jumping, playing, and swimming should be prevented to assist wound healing. The dog should also be prevented from licking the incision site to minimize the risk of infection, either by using an Elizabethan collar or a specially fitted recovery garment.

Will neutering change my dog’s behavior? Neutering removes the sex hormones that can influence some behaviors. It can reduce the desire to roam, urine marking (in males), certain aggressive behaviors, and dominant or attention-seeking behaviors. Neutering can also help control unwanted litters and public demand for breeding. It is not a ‘cure-all’ solution, and persistent problems should still be regularly checked by a veterinarian. Neutering will not improve friendliness or alleviate behavioral conditions such as fear or anxiety. An established behavioral problem may not improve at all. A good puppy school or obedience training course can help set healthy boundaries in your dog’s behavior and improve your relationship as a pet owner.

At what age should I have my dog neutered? Most veterinarians recommend neutering female dogs at least 2-3 months after the first heat, and up to 2 months before the second heat. This recommendation balances the health benefits of breeding and pregnancy with the long-term behavioral effects of neutering after the first heat. The average age of onset of heat varies widely between breeds. For most small breeds, the first heat occurs between 6-9 months, and for most large breeds between 9-18 months. Ultimately, the timing of neutering should be discussed with a veterinarian and customized to your individual dog. Some findings indicate that neutering coats many health risks (non-neoplastic perianal diseases, pyometra, pseudopregnancies, mammary gland tumors, and canine transmissible venereal tumor) of these dogs (M. Belanger et al., 2017). Neutering bitches (female dogs) before their first heat dramatically reduces the risk of mammary gland tumors. Neuter Status is Found to be Independent of Heritable Disorders at the Breed Level.

References:

M. Belanger, J., P. Bellumori, T., L. Bannasch, D., R. Famula, T., & M. Oberbauer, A., 2017. Correlation of neuter status and expression of heritable disorders. ncbi.nlm.nih.gov

M. Oberbauer, A., M. Belanger, J., & R. Famula, T., 2019. A Review of the Impact of Neuter Status on Expression of Inherited Conditions in Dogs. ncbi.nlm.nih.gov

R. Urfer, S. & Kaeberlein, M., 2019. Desexing Dogs: A Review of the Current Literature. ncbi.nlm.nih.gov

Zlotnick, M., Corrigan, V., Griffin, E., Alayon, M., & Hungerford, L., 2019. Incidence of Health and Behavior Problems in Service Dog Candidates Neutered at Various Ages. ncbi.nlm.nih.gov

Kriese, M., Kuźniewska, E., Gugołek, A., & Strychalski, J., 2022. Reasons for and Behavioral Consequences of Male Dog Castration—A Questionnaire Study in Poland. ncbi.nlm.nih.gov

K. Dawson, J., J. Howell, T., B. Ruby, M., & C. Bennett, P., 2019. Throwing the Baby Out With the Bath Water: Could Widespread Neutering of Companion Dogs Cause Problems at a Population Level?. ncbi.nlm.nih.gov