Dog Behavior and Training – Neutering and Behavior

Most male animals (stallions, bulls, boars, rams, dogs, and tomcats) that are kept for companionship, work, or food production are neutered (castrated) unless they are intended to be used as breeding stock. This is a common practice to prevent unacceptable sexual behavior, reduce aggressiveness, and prevent accidental or indiscriminate breeding. However, some dog owners choose not to neuter their male dogs, despite the benefits.

What is castration?

Castration or neutering of male dogs is surgical removal of the testicles (orchiectomy). The procedure involves general anesthesia. An incision is made just in front of the scrotal sac and both testicles are removed, leaving the sac intact. Vasectomies are not performed since this procedure only sterilizes the dog, but does not stop the production of male hormones. It is both sterilization and removal of the male hormones that provide the behavioral and medical benefits of castration. A chemical castration agent has been recently introduced for puppies but, although these products do sterilize dogs to prevent reproduction, they may not prevent or reduce the behavioral signs that can be achieved by castration since hormone levels are still present.

“The only behaviors that will be affected by castration are those that are under the influence of male hormones.”

How does neutering affect behavior?

The only behaviors that will be affected by castration are those that are under the influence of male hormones (see below). A dog’s temperament, training, personality, and ability to do “work” are a result of genetics and upbringing, not its male hormones. Castration does not “calm” an excitable dog, and unless a castrated male dog is overfed or underexercised, there is no reason for it to become fat and lazy.

Which of my dogs’ behavior problems can be expected to improve following castration?

As mentioned, only those behaviors that are “driven” by male hormones can be reduced or eliminated by castration. Although the hormones are gone from the system almost immediately following castration, male behaviors may diminish quickly over a few days or gradually over a few months.

Undesirable sexual behavior: Attraction to female dogs, roaming, mounting, and masturbation can often be reduced or eliminated by castration.

1. Case studies show that for roaming, there was moderate improvement in 70% of dogs, with marked improvement in 40%. For mounting there was moderate improvement in 70% of dogs with marked improvement in 25%.

2. In one study, castration led to reduced aggression toward other dogs in the house in 1/3 of cases, towards people in the family in 30% of cases, towards unfamiliar dogs in 20% of cases and toward unfamiliar people in 10% of cases.

Urine marking: Most adult male dogs lift their legs while urinating. Instead of emptying their bladders completely, most male dogs retain some urine to deposit on other vertical objects that they pass. Some males have such a strong desire to mark that they also mark indoors. Although neutered dogs will still lift their leg to urinate, castration reduces marking in 80% of dogs with a marked improvement in 40%.

“Every aggressive dog should be castrated.”

Aggression: Every aggressive dog should be castrated. At the very least this will prevent reproduction and passing on of any genetic traits for aggression. Castration may also reduce or eliminate some forms of aggression (i.e., those that are influenced by male hormones).

Are there any additional benefits to castration?

Medical benefits: Castration eliminates the possibility of testicular cancer and greatly reduces the chance of prostate disease, two extremely common and serious problems of older male dogs. Many older dogs that are not neutered will develop prostate disease or testicular tumors if they survive to an old enough age. Castration can also reduce the risk of perianal tumors and perineal hernias.

Population control: Perhaps the most important issue is that millions of unwanted dogs are destroyed annually at animal shelters across the United States and Canada. Neutering males is as important as spaying females when it comes to population control.

Are there any risks?

Nowadays, with the broad selection of anesthetic agents and state of the art monitoring, anesthetic or surgical complications rarely occur during a canine castration.

Most young and healthy animals recover without incident. Often, the biggest concern is not the surgery and anesthesia, but the recovery, since we need to ensure that the dog does not lick excessively at its incision line until it is fully healed. Constant monitoring, bitter tasting creams, or a protective collar, known as an Elizabethan collar, will be required if excessive licking is observed following castration. If this is needed, see Elizabethan Collars.

When castration is being considered for an older dog, the benefits must be weighed against any risks associated with anesthetic and surgery. Since castration surgery is seldom associated with any complications, it is the anesthetic that is the primary concern. If castration is being considered as a separate procedure for a medical reason (prostatic enlargement, testicular tumors, perianal tumors), then there is a significant benefit to the dog’s health, comfort and perhaps longevity, in having the castration performed. If the dog is exhibiting any undesirable behaviors that might be improved by castration (roaming, masturbation, mounting, inter-dog aggression, excessive sexual interest or marking), there may also be a significant benefit to be gained from castration. Although not infallible, a physical examination, a series of blood and urine tests and any additional screening that your veterinarian may feel is warranted for your dog (e.g., ECG, chest x-rays), can help to determine if your pet has any significant anesthetic risks. These tests can also help the veterinarian determine which anesthetic protocol would be safest for your pet. Since many older pets require anesthesia for other procedures (e.g., growth removal, preventive dentistry), the benefits can often be further increased, and the number of anesthetic procedures reduced by performing the castration along with the other procedure.

What age is best for preventive castration?

A number of studies have shown that castration is just as effective at reducing male associated behavior problems as it is at preventing them. This means that whether the pet is castrated post-puberty (e.g., 1 year or older) or pre-puberty (e.g., before 6 to 9 months of age) the behavioral effects are likely to be the same. There is, however, anecdotal evidence that dogs that are sexually experienced are more likely to retain their sexual habits after castration, compared to those dogs that have had little or no sexual experience before castration.

It has been advocated recently that castration be performed at as young an age as is practical, to ensure that it is done before the pet has a chance to breed. This is most important in animal shelters, since it allows them to ensure that every dog adopted has already been castrated. Many shelters now routinely begin neutering as young as two months of age. To date, studies have shown that castration at this early age is safe, and has no long-term effects on health or behavior, regardless of the age that it is performed. It has been suggested that surgery at this age is shorter, that recovery is quicker, and that there is less post-operative discomfort for these younger animals. However, if castration is performed before all permanent (adult) teeth have erupted, your dog should be rechecked around 6 months of age to ensure that no deciduous (baby) teeth have been retained.

“There seems to be no behavioral or medical benefit to waiting until a dog is ‘mature’ to perform a castration.”

Once dogs are adopted into their new homes, most veterinarians recommend waiting until all vaccinations are complete before admitting the pet into the hospital for surgery. However, if general anesthesia were needed before the vaccinations being completed for any other reason (e.g., suturing a cut, removing quills) this would be an excellent time to consider castration. In summary, there seems to be no behavioral or medical benefit to waiting until a dog is “mature” to perform a castration.

My dog has retained testicles. What does this mean?

During fetal development or shortly after birth, the testicles will descend into the scrotal sac. In some dogs, likely due to a genetic predisposition, the testicles may not descend into the scrotal sac. These dogs are known as either unilateral (one testicle) or bilateral (both testicles) cryptorchids. The testicle may be retained in the abdomen or anywhere between the abdominal cavity and the external sac. Retained testicles do not usually produce sperm, but they will produce hormones, which can lead to any of the behavioral changes or medical problems previously discussed. In fact, some studies have shown that retained testicles may be more prone to developing cancer. At the very least, it would be extremely difficult to determine if a testicle, which is located in the abdomen, begins to develop cancer, since it cannot be palpated. All dogs with retained testicles should be neutered (and both testicles removed) for medical and behavioral reasons, and to ensure that this genetic abnormality is not perpetuated.

This client information sheet is based on material written by: Debra Horwitz, DVM, DACVB & Gary Landsberg, DVM, DACVB, DECAWBM © Copyright 2012 LifeLearn Inc. Used and/or modified with permission under license.

Neutering in Rabbits

What is neutering?

Neuter is also referred to as orchidectomy or castration. It is a surgical procedure in which the testicles are removed in order to sterilize or render infertile, a male animal.

Why should I have my rabbit neutered?

There are many behavioral and health benefits associated with neutering your rabbit.

  • The obvious benefit is the elimination of unwanted pregnancy if there are intact females present. Although raising baby rabbits might be a wonderful family experience, finding homes for the new rabbits might prove more challenging than one might anticipate.
  • Neutering eliminates the risk of testicular cancers. Reproductive cancers are relatively common in rabbits.
  • Neutered rabbits are much less likely to display undesirable hormone induced behaviors such as mounting, urine spraying (or territorial marking) and aggression.
  • Litter box habits are more stable in neutered animals.
  • Your rabbit may be calmer and easier to handle as it is not experiencing the stresses of sexual frustration.

When should I have my rabbit neutered?

Most rabbits are neutered between four and six months of age. Many veterinarians prefer to neuter at 6 months of age

What does a neuter surgery involve?

This surgical procedure is done under general anesthesia. You must NOT fast your rabbit the night prior to surgery as is done with other animals. Your rabbit will be given a physical examination prior to the operation. Your veterinarian may recommended some pre-operative blood tests. This is to ensure your rabbit is healthy enough to have surgery performed and that there are no pre-existing problems that may compromise your pet. The operation is performed through a small incision in the scrotum or just in front of the penis at the base of the scrotum. The hair in this area will be shaved and surgically prepared prior to the surgery. The testicles are removed. The surgical incision will be closed with sutures under the skin. Most rabbits go home within 24 hours after surgery.

What post-operative care will my rabbit need?

Your rabbit will likely be given pain medication in hospital and may be sent home with several days worth of the same. Keep your pet in a clean, quiet environment and try to minimize excessive running, jumping or hard play that may stress the incision. Feed your rabbit normally, and your should expect he will be eating and drinking within 12-24 hours. Inspect and assess your rabbit and the incision several times daily and report any concerns regarding behavior changes, appetite, drinking, urination and defecation to your veterinarian. Occasionally, rabbits will chew the sutures and open the surgical wound. This needs immediate veterinary attention.

Are complications common with neutering?

In general, complications are rare with this surgery. However, as with any anesthetic or surgical procedure, in any species, there is always a small risk. To minimize risks, it is important to follow all pre-operative instructions and report any signs of illness or previous medical conditions to your veterinarian prior to the day of surgery.

The potential complications may include:

Anesthetic reaction: ? Any animal may have an unexpected adverse reaction to any drug or anesthetic. These reactions cannot be foreseen, but are extremely rare.

Internal bleeding?: This may occur in association with any of the cut or manipulated tissues. This is very rare and is more likely to occur if your rabbit is too active in the days following the surgery. Signs to watch for include weakness, pale gums, listnessness, poor or absent appetite, or a distended abdomen.

Post-operative infection?: Although rare, this may occur internally or externally around the incision site. Infection can be managed with antibiotics. Infections most commonly occur when a pet licks the surgical site excessively or is kept in a damp dirty environment. Monitor the surgical site several times daily for swelling, redness, wound breakdown, pus, or other discharge.

Suture Reaction or Sinus Formation:? This is extremely rare but occurs when a sensitive body reacts to certain types of suture material used during the operation. This results in a draining wound or tract that may appear up to several weeks after the surgery was performed. Further operations may be required to remove the suture material and correct the issue

Will neutering have any adverse effects on my rabbit?

The vast majority of rabbits will experience no adverse effects following neutering.

There are many myths and beliefs about neutering that are not supported by facts or research. Your pet will not become fat and lazy.

Feel free to discuss the pros and cons or any concerns you may have with a veterinarian familiar with rabbits.

This client information sheet is based on material written by: Rick Axelson, DVM

© Copyright 2012 LifeLearn Inc. Used and/or modified with permission under license.