Dog owners may wonder whether neutering affect a male dog's size. This thought makes sense after all, considering that hormones play a role in a dog's growth. Veterinarian Dr. Ivana Crnec discusses what neutering entails, how it may impact a dog's body, then provides details on how neutering may impact a dog's size and growth and why more and more vets are suggesting to neuter dogs at a later age to prevent certain cancers.
Does Neutering Affect a Male Dog's Size?
Recently, there is a growing debate over spaying and neutering dogs. More and more veterinarians, dog enthusiasts and dog parents accent the unspoken risks of spaying and neutering. But how real are these risks?
Most vets recommend early neutering/spaying, in most cases even before reaching 6 months of age or more generally speaking before reaching sexual maturity. The pros of early spaying/neutering are prevention of unwanted pregnancies, reducing the stray population number and reducing the incidence of certain types of cancer.
However, before removing certain parts of the body, it is essential to think about its role. The gonads are not the same as the appendix. You can have your appendix removed and its absence will not be noticed – your daily routine will remain the same. On the other hand, the gonads play a plethora of roles that go far beyond the simple manufacturing process of babies.
The term neutering refers to de-sexing a male dog and it is also known by the name gonadectomy (removal of the gonads or testes). The procedure results in significantly reduced levels of the male hormone testosterone.
Therefore, neutered individuals may exhibit changes in certain hormone-related behavioral and physical attributes. For example, in neutered dogs, the growth plates remain open for a longer period of time and consequently, neutered dogs tend to grow larger in size. Plus, they are more prone to obesity.
The possible side-effects of neutering vary greatly and generally depend on two important factors – the dog’s breed and the dog’s age at the time of neutering.
The Timing of Neutering
If you adopted a shelter puppy chances are it is already neutered. Shelter pups, if healthy enough to undergo the procedure, are neutered when as young as 8 weeks of age. According to certain studies, puppies as young as 7 weeks of age can tolerate the anesthesia better than puppies at the age of 7 months. Additionally, in younger puppies, there were fewer surgery-related complications.
Putting shelters aside, veterinarians usually recommend neutering at the age of 6 months or later. However, this practice has more to do with tradition than it has with science. According to the American Veterinary Medical Association, the vet should decide the best neutering age based on the three factors: the owner’s preferences, the individual dog and dog’s lifestyle.
For example, imagine you have a one year old intact male dog. He has reached the predetermined neutering age, but he is obese. Being obese is an individual factor but it is linked with higher incidence of anesthesia-related complications. In such case, the vet will recommend a weight loss program prior to neutering. Consequently, the neutering will be delayed but once completed, chances are it will go smoothly and your dog will recover in no time.
Negative Effects of Early Neutering
Early neutering (before reaching one year of age) is often linked with several issues. It goes without saying, that, based on this information, it is therefore important keeping these issues in mind. Following are several issues associated with early neutering in dogs.
Increased growth – increased growth in dogs occurs due to the delayed closure of bone plates. The testosterone is responsible for telling the growth plates to stop. If there is no testosterone there will be no stopping signal and the plates will stay open. Since the plates remain open for a longer period of time, the bones grow longer and the dog gets higher. It goes without saying that being taller is not an issue on itself. However the increased growth in length is not always proportional across the joint which leads to: increased risk of hip dysplasia later on in life – as a result of alterations in the joint conformation., increased risk of cranial cruciate ligament tears followed by impaired rear leg function. This issue is also breed-related. Namely, it is particularly common in Golden Retrievers.
Increased risk of obesity – the increase in height is often linked with increased chances of becoming obese later on in life.
Increased risk of certain types of tumors- namely, cardiac tumors – neutered individuals are up to five times more likely to develop this type of tumor than intact dogs. Bone cancer – this is particularly true for large breed purebreds in which the neutering procedure increases the risk for as much as 25 percent. Lymphosarcoma – early-neutered dogs are three times more likely to suffer this condition than intact males.
Decreased longevity – a recent study showed that early neutering reduces the life expectancy significantly. In certain breeds, like the Rottweiler, the expectancy can be reduced for as much as up to thirty percent. Individuals with intact gonads are nine times more likely to reach exceptional longevity (more than 13 years of age).
Increased risk of hypothyroidism – the gonads are hormone-producing organs. To maintain balance, when a hormone-producing organ is removed from the body, the rest of the hormone-producing organs are forced to compensate. This often leads to over-stressing. Therefore, it has been shown that neutered dogs are more likely to develop hypothyroidism.
Increased risk of urinary incontinence – neutering increases the risk of developing urinary incontinence in both sexes. In males this is achieved by altering the capacity of the urethral sphincter.
Behavioral changes – some studies suggest that neutered dogs are more prone to sound phobias, developing aggression towards family members and excessive barking. What is more, it has been demonstrated that mental issues tend to get worse in neutered individuals.
Wooly coat – groomers often complain that neutered individuals develop a wooly coat that it popularly known as "spay coat.". It is assumed that such coat develops as a result of overproduction of the undercoat due to hormonal imbalance.
The Bottom Line
Each choice you make for your dog has its consequences – the type of dog food you use, the frequency of parasite control, annual boosting. Each decision should be fact-based and well researched. This includes the decision whether or not to have your dog spayed/neutered.
If you parent a male dog which you do not plan on breeding and are considering having him neutered, it is highly advisable to talk to your trusted vet. The vet will explain the pros and cons of this procedure and also help you determine the best time to neuter your canine baby.
About the Author
Dr. Ivana Crnec is a graduate of the University Sv. Kliment Ohridski’s Faculty of Veterinary Medicine in Bitola, Republic of Macedonia.
She currently practices as a veterinarian in Bitola and is completing her postgraduate studies in the Pathology of Domestic Carnivores at the Faculty of Veterinary Medicine in Zagreb, Croatia.
Ivana’s research has been published in international journals, and she regularly attends international veterinary conferences.