Spay and Neuter: When and If ever?

[megansmomma]

Why do we perform spay or castration at 6 months of age?
Most veterinarians in the United States recommend bitches and dogs be spayed or castrated between 6 and 9 months of age. This is not based in science; no one has performed a large-scale study in which bitches and dogs underwent gonadectomy at various ages and were tracked throughout life to determine what abnormalities developed relative to age at gonadectomy. It is thought that the current age recommendation arose after the World War II, when increasing affluence of American families first permitted them to treat animals as household pets and were, therefore, more interested in controlling manifestations of reproductive hormone secretion and very interested in making sure the animal survived surgery. Anesthetic and surgical techniques available at that time necessitated the animal be at least 6 months of age.

With current anesthetic agents, anesthetic monitoring equipment, and surgical techniques, it has been demonstrated in multiple studies that bitches and dogs can safely undergo gonadectomy when as young as 6 to 8 weeks of age. Surgical complication rate does not vary between groups undergoing surgery when very young compared to those undergoing surgery at the more traditional age, with overall postoperative complication rate reported as 6.1%. The vast majority of these post surgical complications are transient and do not require veterinary care.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Effects of gonadectomy on behavior
Behaviors that are most likely to be affected by gonadectomy are those that are sexually dimorphic (seen primarily in one gender). Examples of sexually dimorphic behaviors include flagging in bitches, and mounting and urine marking in dogs. Incidence of sexually dimorphic behaviors decreases after gonadectomy in bitches and dogs, with the decrease in incidence not correlated with length of time the animal has shown the behavior prior to gonadectomy.

Those behaviors that are not sexually dimorphic, including most forms of aggression, are not decreased in incidence by gonadectomy. One behavioral consequence of spaying that has been documented in several studies is an increase in reactivity towards humans with unfamiliar dogs and increased aggression toward family members. This may be hormonally related; there may also be a breed predisposition.

There is no evidence documenting a decline in trainability of working female or male dogs after spay or castration. One study documented an increase in development of senile behaviors after gonadectomy in male dogs. However, that study had very few dogs in the intact male group and other studies, looking directly at changes in brain tissue, are not supportive of that finding.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Effects of gonadectomy on health
Neoplasia
Neoplasia, or cancer, is abnormal growth of tissue. Benign tumors tend to stay in one location and cause disease by altering the single tissue involved and compressing tissue around it. Malignant tumors tend to spread in the area from which they arise and to spread to distant tissues, causing widespread disease. Virtually all tumors are more common in aged than in young animals, with average reported age at time of diagnosis of about 10 years. For the tumor types described below, exact cause-and-effect relationship between gonadectomy and development of tumors is unknown.

Mammary neoplasia, or breast cancer, is a very common disorder of female dogs, with a reported incidence of 3.4%; this is most common tumor type in female dogs. Of female dogs with mammary tumors, 50.9% have malignant tumors. Risk factors for mammary neoplasia in female dogs include age, breed (Table 1), and sexually intact status. Multiple studies have documented that spaying bitches when young greatly decreases their risk of developing mammary neoplasia when aged. Compared with bitches left intact, those spayed before puberty have a 0.5% risk, those spayed after one estrous cycle have an 8.0% risk, and dogs spayed after two estrous cycles have a 26.0% risk of developing mammary neoplasia later in life. Overall, unspayed bitches have a seven times greater risk of developing mammary neoplasia than do those that are spayed. While the benefit of spaying decreases with each estrous cycle, some benefit has been demonstrated in bitches even up to 9 years of age. The exact cause-and-effect relationship between intact status and development of mammary neoplasia in female dogs has not been identified. The genetic and hormonal causes of breast cancer identified in women have not been consistently identified in female dogs despite extensive research.

Prostatic cancer in dogs is uncommon, with a reported incidence of 0.2 to 0.6%. Prostatic adenocarcinoma is a highly malignant tumor that cannot be cured medically or surgically. A 2.4 to 4.3 times increase in incidence in prostatic neoplasia with castration has been demonstrated, with that information verified in multiple studies.

Testicular neoplasia is a very common tumor in dogs, with a reported incidence of 0.9%. Unlike in humans, testicular tumors occur late in life in dogs, are readily diagnosed, and are rarely malignant. Ovarian and uterine tumors are very uncommon in bitches.

Several tumors of non-reproductive tissues have been reported to be increased in incidence after gonadectomy. Transitional cell carcinoma, a malignant tumor of the urinary tract, was reported in two studies to occur 2 to 4 times more frequently in spayed or castrated dogs than in intact female or male dogs. Exact incidence is not reported; estimated incidence is less than 1.0%. A breed predisposition exists (Table 1). Surgical removal of transitional cell carcinoma may or may not be possible, depending on site of the primary tumor.

Osteosarcoma is a low incidence (0.2%), highly malignant tumor of bone. It is reported to be more common in large breed dogs with some specific breeds predisposed (Table 1). Two studies have documented a 1.3 to 2.0 times increased incidence of osteosarcoma with gonadectomy. However, one study evaluated solely Rottweilers, a breed with a reported genetic predisposition. Treatment often includes limb amputation and radiation or chemotherapy.

Hemangiosarcoma is a malignant tumor of vascular tissue, including the heart, major blood vessels, and spleen. Large breeds in general are at increased risk with some breeds specifically predisposed (Table 1). Two studies have documented increased incidence, from 2.2 to 5 times, in gonadectomized males and females compared to intact animals. Overall incidence of hemangiosarcoma is low, at 0.2%. Surgical removal is the treatment of choice, if possible.

- See more at: http://www.akcchf.org/canine-health/...-at.html#Table 3

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Orthopedic abnormalities
Long bones grow from growth plates on either end. The growth plates close after exposure to estrogen and testosterone, explaining why growth in height is largely completed after puberty. In bitches and dogs, removal of the gonads before puberty slows closure of the growth plates, leading to a statistically significant but not overtly obvious increase in height. There is no evidence that after gonadectomy some growth plates will close on time and some late, however most studies have only examined long bones of the forelimb. No studies have demonstrated increased incidence in fractures or other abnormalities of the growth plates associated with age at time of spay or castration.

Hip dysplasia is abnormal formation of the hip joint with associated development of arthritis. Genetic, hormonal, and environmental factors, including diet, are involved (Table 1). In the one study describing increased incidence of hip dysplasia in female or male dogs spayed or castrated before 5 months of age, it is not clear that the diagnosis of hip dysplasia was made by a veterinarian in all cases.

The paired cruciate ligaments form a cross within the knee (stifle) joint. The cranial cruciate ligament (CCL) undergoes tearing or complete rupture when the stifle is stressed from the side, especially if the animal twists while bearing weight on that limb. CCL injury is very common, with reported incidence of 1.8%. Large breed dogs are generally at risk, with some breeds predisposed (Table 1). Overweight female and male dogs also may be at increased risk. It has been demonstrated that CCL injury is more common in spayed or castrated animals than in intact animals. The basis may be hormonal, as it has been demonstrated that CCL injury in humans is more common in women than in men with incidence varying with stage of the menstrual cycle. A very recent study documented change in anatomy of the stifle joint of female and male dogs with CCL injury with gonadectomy prior to 6 months of age; further research is pending. CCL injury is treated with surgery and rehabilitation; treatment is costly and recovery protracted.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Obesity
Obesity is very common in dogs, with reported incidence of 2.8% in the general dog population; incidences of 34% of castrated male dogs and 38% of spayed female dogs were reported in one study. Multiple risk factors exist, including breed (Table 1), age, and body condition and age of the owner. A very commonly reported risk factor for development of obesity is gonadectomy. In cats, it has been demonstrated that gonadectomy causes a decrease in metabolic rate. There are no reports documenting metabolic rate in female or male dogs relative to gonadectomy. Obesity is itself a risk factor for some forms of cancer, CCL injury, diabetes mellitus, and decreased life span. Obesity is controllable with appropriate diet and exercise. - See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Urinary incontinence
A very common form of urinary incontinence, formerly termed estrogen-responsive urinary incontinence and now more commonly called urethral sphincter mechanism incompetence, occurs in spayed female dogs. Urine leaks from the spayed female dogs when they are relaxed and so most often is seen by the owners as wet spots where the dog sleeps. Reported incidence ranges from 4.9 to 20.0%, with female dogs weighing more than 44 pounds and some specific breeds predisposed (Table 1). While multiple studies have documented correlation between gonadectomy and occurrence of this disorder, only one has demonstrated a correlation between incidence and age at gonadectomy. In that study, it was demonstrated that spaying before 3 months of age was significantly more likely to be associated with eventual occurrence of urinary incontinence in a given female dog than was spaying later. Urethral sphincter mechanism incompetence is easily controlled medically in most female dogs.

Pyometra
Pyometra is uterine infection overlying age-related change in the uterine lining. Incidence increases with age; 23 to 24% of dogs developed pyometra by 10 years of age in one Swedish study. Specific breeds are at increased risk (Table 1). This very common disorder of aged intact bitches is treated surgically.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Benign prostatic hypertrophy/prostatitis
Benign prostatic hypertrophy (BPH) is age-related change in prostate size. By 6 years of age, 75 to 80% of intact male dogs will have evidence of BPH; by 9 years of age, 95 to 100% of intact male dogs will have evidence of BPH. The increased size of the prostate is associated with increased blood supply. The most common clinical signs are dripping of bloody fluid from the prepuce and blood in the semen. Development of BPH predisposes the dog to prostate infection (prostatitis). Medical therapy for BPH can be used to control clinical signs but surgical therapy (castration) is curative.

Diabetes mellitus
Only one study has demonstrated a possible increased incidence of diabetes mellitus in dogs associated with gonadectomy. That study did not consider the effect of obesity, a known risk factor for diabetes mellitus.

Hypothyroidism
Two studies have demonstrated increased incidence of hypothyroidism in female and male dogs after gonadectomy. Genetic factors also are involved (Table 1). Cause-and-effect has not been described, nor has a specific numerical factor for increased incidence been reported.　

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[megansmomma]

Conclusion
So how do you reconcile all this information in helping make decisions for individual animals? Considerations must include evaluation of incidence of various disorders, breed predisposition, and health significance of the various disorders (Table 2 and Table 3).

For female dogs, the high incidence and high percentage of malignancy of mammary neoplasia, and the significant effect of spaying on decreasing its incidence make ovariohysterectomy prior to the first heat the best recommendation for non-breeding animals. The demonstrated increased incidence of urinary incontinence in bitches spayed before 3 months of age and possible effect of CCL injury in bitches spayed before 6 months of age suggest that spaying bitches after 6 months of age but before their first heat is most beneficial. For bitches of breeds predisposed by ovariohysterectomy to highly malignant tumors and for breeding animals, spaying at a later age may be more beneficial.

For male dogs, castration decreases incidence of disorders with little health significance and may increase incidence of disorders of much greater health significance. For non-breeding animals, evaluation of breed and subsequent predispositions to disorders by gonadectomy should guide when and if castration is recommended.

As dog breeders, you are a source of information for people seeking a dog for companionship, to show or work as a hobby, or to grow up with their children. As veterinarians, we are one of the guardians of safety and good health for all animals in our society. It behooves all of us to thoughtfully consider why we recommend spay or castration for dogs, to ensure we are not putting our own convenience above their good health. For every individual bitch or dog, careful consideration of their breed, age, lifestyle, and suitability as a breeding animal must be a part of the decision as to when or if they should undergo gonadectomy.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3

[gemy]

[QUOTE=megansmomma;4451160]Conclusion
So how do you reconcile all this information in helping make decisions for individual animals? Considerations must include evaluation of incidence of various disorders, breed predisposition, and health significance of the various disorders (Table 2 and Table 3).

For female dogs, the high incidence and high percentage of malignancy of mammary neoplasia, and the significant effect of spaying on decreasing its incidence make ovariohysterectomy prior to the first heat the best recommendation for non-breeding animals. The demonstrated increased incidence of urinary incontinence in bitches spayed before 3 months of age and possible effect of CCL injury in bitches spayed before 6 months of age suggest that spaying bitches after 6 months of age but before their first heat is most beneficial. For bitches of breeds predisposed by ovariohysterectomy to highly malignant tumors and for breeding animals, spaying at a later age may be more beneficial.

For male dogs, castration decreases incidence of disorders with little health significance and may increase incidence of disorders of much greater health significance. For non-breeding animals, evaluation of breed and subsequent predispositions to disorders by gonadectomy should guide when and if castration is recommended.

As dog breeders, you are a source of information for people seeking a dog for companionship, to show or work as a hobby, or to grow up with their children. As veterinarians, we are one of the guardians of safety and good health for all animals in our society. It behooves all of us to thoughtfully consider why we recommend spay or castration for dogs, to ensure we are not putting our own convenience above their good health. For every individual bitch or dog, careful consideration of their breed, age, lifestyle, and suitability as a breeding animal must be a part of the decision as to when or if they should undergo gonadectomy.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3[



The link as all my links were posted, those that want to read the full article can do so.


For male dogs, castration decreases incidence of disorders with little health significance and may increase incidence of disorders of much greater health significance. For non-breeding animals, evaluation of breed and subsequent predispositions to disorders by gonadectomy should guide when and if castration is recommended.

And so we see and article why I say male castration has no overweeing health benefits.

[megansmomma]

[quote=gemy;4451171]

Originally Posted by megansmomma

Conclusion
So how do you reconcile all this information in helping make decisions for individual animals? Considerations must include evaluation of incidence of various disorders, breed predisposition, and health significance of the various disorders (Table 2 and Table 3).

For female dogs, the high incidence and high percentage of malignancy of mammary neoplasia, and the significant effect of spaying on decreasing its incidence make ovariohysterectomy prior to the first heat the best recommendation for non-breeding animals. The demonstrated increased incidence of urinary incontinence in bitches spayed before 3 months of age and possible effect of CCL injury in bitches spayed before 6 months of age suggest that spaying bitches after 6 months of age but before their first heat is most beneficial. For bitches of breeds predisposed by ovariohysterectomy to highly malignant tumors and for breeding animals, spaying at a later age may be more beneficial.

For male dogs, castration decreases incidence of disorders with little health significance and may increase incidence of disorders of much greater health significance. For non-breeding animals, evaluation of breed and subsequent predispositions to disorders by gonadectomy should guide when and if castration is recommended.

As dog breeders, you are a source of information for people seeking a dog for companionship, to show or work as a hobby, or to grow up with their children. As veterinarians, we are one of the guardians of safety and good health for all animals in our society. It behooves all of us to thoughtfully consider why we recommend spay or castration for dogs, to ensure we are not putting our own convenience above their good health. For every individual bitch or dog, careful consideration of their breed, age, lifestyle, and suitability as a breeding animal must be a part of the decision as to when or if they should undergo gonadectomy.

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3[



The link as all my links were posted, those that want to read the full article can do so.


For male dogs, castration decreases incidence of disorders with little health significance and may increase incidence of disorders of much greater health significance. For non-breeding animals, evaluation of breed and subsequent predispositions to disorders by gonadectomy should guide when and if castration is recommended.

And so we see and article why I say male castration has no overweeing health benefits.

You cannot pick and chose certain sentences from an entire article that you link to bolster your point. That is unfair to the reader and you and I both know that people with do a quick glance read of information. When doing this you are swaying the reader into your point of view.

[Maximo]

Originally Posted by gemy

Table 3. Conditions associated with castration
CONDITION

INCIDENCE
HEALTH SIGNIFICANCE
INCREASED OR DECREASED WITH GONADECTOMY

Testicular neoplasia

High
Low
Decreased

Benign prostatic hypertrophy

High
Low
Decreased

Prostatic neoplasia

Low
High
Increased

Transitional cell carcinoma

Low
High
Increased

Osteosarcoma

Low
High
Increased

Hemangiosarcoma

Low
High
Increased

CCL injury

High
High
Increased

Obesity

High
Moderate
Increased

Diabetes mellitus

High
Low
Increased

Hypothyroidism

High
Low
Increased

- See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation

Looking at the conditions listed for high incidence in neutered males, in my opinion, these could easily be explained by environmental (human influenced) factors. Using Rhetts mama's line, it is a leap to go from correlation to causation. (sorry if I missed something; loads of information in this thread to digest).

Humans who neuter their pets might be more likely to indulge their pets with food, leading to obesity and all of these related problems, which may also be linked to some cancers.

I don't think it is right to say that being neutered *causes* obesity in males. It is harder to keep a neutered male at the right weight (ahem, Max ), like it is harder to keep weight on an intact male who is around a bitch in heat. An adjustment of diet is needed according to activity level, same as when a dog matures from puppy to adulthood.

[Maximo]

I can't find the quote related to aggression that said human disposition, a placebo affect, following castration of a pet, may influence training and therefore behavior of the pet. Wanted to say that it sounds plausible to me.

I had written earlier that I cannot be convinced that an intact dog is not more likely to be aggressive and more likely to roam. Now I'm thinking it might say more about the average pet guardian (not talking about breeders).

[Maximo]

Originally Posted by Maximo

I don't think it is right to say that being neutered *causes* obesity in males. It is harder to keep a neutered male at the right weight (ahem, Max ), like it is harder to keep weight on an intact male who is around a bitch in heat. An adjustment of diet is needed according to activity level, same as when a dog matures from puppy to adulthood.

I should qualify this statement and say it *can* be harder. Teddy naturally has a very high metabolism. That was evident from puppyhood and he has maintained it.

I do not believe Max would have been a better self-regulator if he had not been neutered. There is definitely an indulgence factor. We give him more food than he needs.

The spayed females we had in the past maintained perfect weight all of their lives because we fed them twice a day and they received zero treats. None!

[pstinard]

[quote=megansmomma;4451094]

Originally Posted by chachi

These are all parts of the same Journal of American Veterinary Medicine which is a pay site so I cannot get the full content of the article. I will post the entire article below.

Gonadectomy in immature dogs: effects on ... [J Am Vet Med Assoc. 1991] - PubMed - NCBI

ARRRGGGGHHHH!!! The JAVMA online archives only go back to the year 2000. How low tech of them!

[megansmomma]

Originally Posted by Maximo

Looking at the conditions listed for high incidence in neutered males, in my opinion, these could easily be explained by environmental (human influenced) factors. Using Rhetts mama's line, it is a leap to go from correlation to causation. (sorry if I missed something; loads of information in this thread to digest).

Humans who neuter their pets might be more likely to indulge their pets with food, leading to obesity and all of these related problems, which may also be linked to some cancers.

I don't think it is right to say that being neutered *causes* obesity in males. It is harder to keep a neutered male at the right weight (ahem, Max ), like it is harder to keep weight on an intact male who is around a bitch in heat. An adjustment of diet is needed according to activity level, same as when a dog matures from puppy to adulthood.

That was my point if posting the entire article. When you read the article along with this chart it kind of discredits several of the highs as being human not spay/neuter related. It was repeatedly numerous times that these states were in large or giant breed dogs as well and that there are no studies for small breed animals.