|
Quote:
I too am very concerned about poor placement habits....but I accepted long ago that I can only do what I can for those in my care. |
Growth Plate Closure - Range (days) Closure - Average (days) FORELIMB Proximal radial epiphysis 136-330 258 Distal radial epiphysis 136-510 318 Proximal ulnar epiphysis 161-450 258 Distal ulnar epiphysis 217-450 308 The smaller the animal the quicker the growth plates will close. So you can see from the chart that there is a HUGE range in how quickly growth places will as we all know that a Yorkie is on the smallest end of the scale and we go up from there. It is not just dogs that have growth plates that close over time all mammals do such as an elephant. Which BTW I just learn because they are so large it might take years for their bones to fully close. |
Quote:
|
Quote:
http://www.vsoak.com/web/images/stor...ture%20Dog.pdf |
Quote:
|
Quote:
|
[quote=chachi;4451077] Quote:
There are multiple studies in medium to large breeds that show the incidence of HD is increased anywhere from 1.5x to 2x for some breeds. The incidence of hemangiosarcoma in certain breeds like the Golden Retreivers is such that almost 1 in 5 GR die from this disease anywhere from 5-7 yrs old. The incidence of osteoscarcoma is also increased as well at least 2 fold. When you have a breed (medium to large) that has a greater than 20% incidence rate of HD, and you see numbers from studies that say early neutering increases the likelihood of Hd or ED as the case might be by 20 or 50 or more % what do you do as a responsible pet owner? Here is one of the values of research, if your breed has a 20% incidence rate of HD and early s/n increases their likelihood of moderate to severe HD or ED by a factor of 2 then you have some health decisions to make. At this point in time the options of successful surgery are limited with large breeds. If you could wait until 18months or more and decrease the risk or reduce it to 20% why not wait? There are more than a few studies that show dogs go taller, are more narrow, and the joint angulations are more steep. Again in large to medium breeds that were s/n from early 6months old or less. Before boney plate closure. In terms of toy breeds as no studies on this particular issue of LP has been done specifically looking at boney plate closure, and angulations, but we do know that sharpened angulation here does pre disposed to luxation in other breeds why not err on the side of caution and wait to boney plate closure? In small breeds anywhere from 8mths to 1 yrs old. Again there is no guess work, take a lateral view of the tibial plate as this one is the last to close, if it is closed then go ahead an spay. Even a general vet should be trained enough to ascertain if these growth plates have closed on Xray examination.. And Xray exams are not expensive $40 or so. There is a reason why so many studies are being done on medium to large breeds. That is because the National Clubs and concerned Vets and citizens are agitating for it. Because so many of our large breeds are suffering from crippling HD and or ED and cancers of many kinds. Despite all the testing that responsible breeders do. Did you know in Europe that hemagiosarcoma in GR's are almost un-heard of? Did you know that generally speaking Europe does not automatically s/n dogs? The pre-ponderance of the evidence is starting to be built here how s/n takes this beautiful wonderful breed at a huge risk for hemangiosarcoma! Not a message the vet world wants to hear, or I imagine the sheilters as well. But yet again there are options to do vascetomies and tubal ligations that keep the sex hormones intact. At this point in time I would never ever recommend a person to adopt a large breed dog that was s/n at under 18 months old. The adopters should not be subjected to the costs and the emotional turmoil of trying to care for a dog with severe HD or ED. |
Quote:
|
New Views on Neutering Back to Table of Contents By Ruth Marrion, DVM Everyone seems to have an opinion when it comes to neutering dogs. Some opinions are based on fact while others could not be farther from the truth. How many times have you heard pet owners say, "I don't want to spay my bitch because she'll become fat and lazy," "I want her to have one litter before she's spayed because that will improve her personality," or "I don't need to spay (or castrate) my dog because there aren't other dogs around"? Breeders should have rational, factual arguments ready at their fingertips to respond to these types of misguided statements. Yet despite the fact that people have been neutering* animals since ancient times (writings that discuss canine castration date back as far as 284 BC!), information on the physiological and behavioral effects of neutering has been sparse until recent years. With little scientific data available on the subject, misinformation regarding neutering has been freely disseminated. This article will discuss some recent scientific studies regarding the physical and behavioral effects of neutering dogs, and explore the concept of early neutering—that is, prior to five to seven months of age. Early neutering was developed to help alleviate the pet overpopulation problem, and may prove to be of further benefit to dog breeders. *Neutering is a term applicable to an animal of either sex that has had both ovaries or testes removed. This includes dogs who have undergone an ovariohysterectomy (removal of the ovaries and uterus), ovariectomy (removal of the ovaries alone) or orchieclomy (removal of the testes). Unneutered animals are referred to as being sexually intact Behavioral Effects of Neutering The estrous cycle of the intact bitch is divided into several stages. The first stage of the cycle is proestrus, in which the bitch is attractive to males but is not receptive to mating. This is followed by estrus (derived from the Greek meaning "mad desire"), in which the bitch is receptive to dogs. The onset of the next stage, diestrus, is defined as the first day after an estrus period when a bitch will no longer accept a dog. The female hormones estrogen and progesterone, which are produced by the ovary, control the estrous cycle. Estrogen promotes the bitch's desire to mate (behavioral estrus), stimulates growth of the uterus and mammary gland, and sensitizes the uterine muscle to oxytocin, a hormone, during estrus and whelping. Progesterone enhances the effect of estrogens in causing behavioral estrus, and acts in concert with estrogens to promote uterine and mammary growth. Removal of both ovaries also removes the source of estrogen and progesterone, thus resulting in the abolition of estrous cycles. Since these hormones are responsible for sexual activity, bilateral ovariectomy almost always results in cessation of copulatory behavior for the bitch. The reason that copulatory behavior is not always abolished is not completely clear, but mounting behavior in females has been found not to depend on the presence of estrogen. For example, my Sheltie bitch was spayed as a puppy and at four years of age, she still engages in mounting activity during play with her neutered brother. Lots of people believe that inactivity and weight gain follow ovariohyslerectomy in the bitch. These changes, however, are difficult to distinguish from changes due to normal maturation. Recent studies have tried to uncover the truth about these supposed effects of spaying. One report on gonadectomy (removal of the ovaries or testes) in immature dogs' determined that neutered dogs were actually more active than sexually intact dogs. Gonadectomy was found to neither affect food intake nor weight gain. But another group of researchers, comparing food intake in sexually intact and neutered Beagle bitches fed ad libitum, concluded that neutered bitches ate much more than their sexually intact counterparts. In yet another study5, activity level and weight fluctuations in spayed bitches were compared to those of intact females. The spayed bitches did not gain weight on a diet of a fixed amount of commercial dog food. No data on the effect of orchiectomy on food intake and weight gain in male dogs, other than the study on immature dogs, has been published to date. The bottom line is that the available scientific evidence about whether neutering influences weight gain and activity in dogs shows that the question is, as yet, unresolved. In other words, it's too early for breeders to jump to either conclusion and therefore, one can't assume the worst. Eliminating undesirable behavior is often cited as a reason for neutering male animals. Behavior patterns that are altered by neutering are generally male-specific actions such as urine marking, mounting, and intermale aggression. These three types of behaviors, in fact, have been shown to be markedly reduced or eliminated in 50 to 60 percent of dogs as a result of neutering. Behavior patterns common to both males and females, such as watchdog barking, playfulness and attention seeking, are not affected by neutering. No basic personality or behavior changes occur as a result of neutering, with the exception that undesirable male behaviors may be reduced or eliminated. It is interesting to note that the age at which an animal is neutered does not affect the likelihood that neutering will have an impact on a particular behavior. The chance that neutering will prevent an objectionable male behavior in a pre-pubertal animal is approximately equal to the likelihood that the same behavior will be abolished by neutering an adult animal2. Experience, on the other hand, does appear to play some role in determining how quickly an undesirable behavior ceases to exist. Copulatory behavior in experienced male dogs may not end completely for months to years following castration. Residual testosterone is not a contributing factor for persistent male-specific behavior patterns, since the hormone is so rapidly metabolized by the body that it is virtually undelectable eight hours following castration. Finally, many pet owners nurture the belief that bitches become more even-tempered if they produce one litter before being spayed. Neither clinical observations nor animal behavior research bear this out. True, a bitch's behavior will change temporarily as a result of the hormonal changes during pregnancy and lactation, but these effects are transient—not permanent, as some believe. But if the owners of a bitch manage to convince themselves that her behavior will change as a result of whelping, their way of dealing with the bitch may change, and thereby influence the bitch's ensuing behavior. This is known as the placebo effect2. There are other circumstances where an owner's expectations and resulting behavior can influence a dog. The placebo effect also plays a role, for instance, when people anticipate certain changes to take place following neutering— weight gain, for example, or decreased activity. Without realizing the implications of their actions, many owners will actually start to feed the neutered animal more food and place fewer physical demands on it. The result: an overweight, sedentary (neutered) animal. Just what owners expected! The specialized training of behavioral scientists helps them differentiate between various influences on an animal's behavior. Data from their controlled studies are therefore generally more valuable than observations made by casual observers on a limited number of animals. |
Physical and Medical Effects Intact bitches are susceptible to several diseases of the reproductive tract and mammary glands. Removing the ovaries and uterus greatly decreases or eliminates the risk of a bitch developing the following disorders: 1) Mammary cancer. Mammary gland cancer is the most common tumor of the sexually intact bitch. The beneficial effects of bilateral ovariohysterectomy in preventing the development of mammary cancer have been well documented4. Sexually intact bitches have three to seven times the risk of developing mammary gland cancer compared to neutered bitches. The timing of neutering is critical if mammary cancer is to be avoided. Bitches spayed prior to their first estrus have been reported to have 0.5 percent risk of developing mammary cancer. If spaying is delayed for one to two heat periods, however, the chance of a female developing a tumor jumps to 8 and 26 percent, respectively. Little sparing effect is seen in bitches neutered later in life. Regardless of age, ovariohysterectomy is often performed concurrently with mammary tumor removal. The reason for this is that a number of these tumors have the potential to metastasize to other areas of the body. The cells which have metastasized, like the parent mammary cancer cells, are often stimulated by female sex hormones. Ovariohyslereclomy removes the source of female hormones and thereby decreases progression of the disease. 2) Pyometra. Meaning "pus in the uterus," pyometra is a common disease of intact bitches, usually affecting individuals over six years of age. This condition develops as a result of the influence of progesterone on the uterus during diestrus. Progesterone promotes growth of the endometrium (the lining of the uterus), and secretion of uterine glands. These secretions provide a me-dium for bacterial growth. In addition, progesterone inhibits the infection-fighting activities of uterine white blood cells. Signs of pyometra include varying degrees of illness along with an increase in drinking and urination in an older intact bitch. Blood analysis and abdominal radiographs are used to confirm clinical suspicion. Ovariohysterectomy is the only acceptable treatment for pyometra. Medical treatment using antibiotics, prostaglandins, hormones and supportive therapy is generally unsuccessful. Removal of the uterus and ovaries at any age will prevent development of pyometra. 3) Vaginal prolapse. This condition occurs in response to the effects of estrogen on the lining of the vagina. Estrogen causes this tissue to become edematous (swollen) and protrude from the vulva, becoming subject to trauma or self-mutilation by the bitch. Ovariohysterectomy prevents this condition from developing. Potential adverse effects of ovariohysterectomy are uncommon and of less significance than the beneficial effects. A condition of estrogen-responsive urinary incontinence develops in a small proportion of spayed bitches (one researcher found a 4 percent incidence10). The incontinence condition generally responds to treatment with oral medication. Many individuals feel that their bitch should go through one estrous cycle prior to being spayed. There is one situation in which this should be considered—the case of puppy vaginitis. Some puppy bitches develop a vaginitis because the lining of their vagina is thin. This is often alleviated after one estrous cycle. The effect of the estrogen produced during the estrous cycle is to thicken the vaginal lining, making it less susceptible to infection. If a bitch who has been spayed before her first estrous cycle continues to exhibit signs of vaginitis, antibiotic and hormone therapy may be initiated to treat the problem. The Early Sterilization Program Dr. Michael Aronsohn, director of the Early Sterilization Program (ESP) at the Massachusetts SPCA's Angell Memorial Animal Hospital, sees .the. ESP as a boon to pure-bred dog breeders. "The program is useful to breeders because they can get pet quality puppies neutered as early as six weeks of age,.prior to placing them in homes," says Dr. Aronsohn, a Diplomate of the American College of Veterinary Surgeons and head of the Department of Surgery at Angell Memorial's affiliated Boston shelter. "Breeders can bring in litters to be neutered and the puppies will be ready to go to their new homes•a few days after surgery. Dr. Aronsohn and anesthesiologist Dr. Alicia Faggella have ! neutered several hundred puppies and kittens with no apparent ill effects. At another animal shelter, in Medford, Oregon, a study of 8,000 puppies and kittens neutered at eight to 12 weeks of age also reported no undesirable effects.1 When asked about the safety of early neutering, which has been in existence for nearly 20 years, Dr. Aronsohn replied, "Anesthetic protocols have been worked out, and are as safe in the younger puppies as they are in the ones five to eight months old. We previously thought that, hypoglycemia was going to be a problem, but it has turned out not to be." The Angell Memorial team has neutered litters of puppies "and kittens as young as six to eight weeks old for several area breeders. Dr. Aronsohn recommends that interested breeders contact their local humane association for information on shelters and hospitals in their area that perform early neutering.—RM l. Kellington E, Hannawalt EH. Study of the effects of early spaying and neutering. Medford, Oregon SPCA Rep. May 1985. In the absence of puppy vaginitis, there is no reason that a bitch should not be spayed prior to her first estrus. The sparing effect on mammary cancer development alone is reason enough not to delay ovariohysterectomy. Beneficial Effects of Castration Neutered dogs are at less risk of developing some diseases than their sexually intact counterparts. The most important of these are prostatic disease and testicular cancer. Benign prostatic hypertrophy is an androgen (male sex hormone) related disorder of the prostate gland in which the gland enlarges and becomes more susceptible to infection. Prostatic infection may spread to involve the bloodstream (sepsis) or abdominal cavity, and may result in death. Benign prostatic hypertrophy is both prevented and treated by castration. Testicular cancer is a potential danger to intact male dogs. Cryptorchid dogs are actually at greater risk of developing testicular cancer than normal intact dogs. In one study of 410 dogs cryptorchids were found to have 13.6 times the risk of normal dogs for developing testicular cancer11. Sertoli cell tumors are a type of cancer more often seen in cryptorchids than in intact males. This condition can cause a life-threatening bone marrow suppression. |
Quote:
And, I don't know where you have xrays done, but my vet is very reasonable and charges $80. I really have not heard of anyone doing them for less around here. People won't pay $4/month for Heartgard...again...unrealistic. |
Early Neuters The pet overpopulation problem in the United States has reached enormous proportions. In 1987, for example, between 6.3 and 10.4 million dogs were euthanatized in shelters in the United Stales. Most animal care facilities have instituted mandatory neuter policies as an attempt to reduce the number of unowned and unwanted animals. They require that owners who adopt kittens and puppies have them neutered at five to eight months of age. As one would expect, follow-up and enforcement of these policies are difficult at best. Compliance rates average only 50 to 60 percent, with the result that many animals remain sexually intact and reproduce prolifically. Current practice among veterinarians in the United States is to neuter puppies between five and eight months of age. However, there is little information in the veterinary literature regarding the optimal age for performing spays and castrations. Since some dogs reach sexual maturity prior to six months of age, a number of dogs are neutered after reaching sexual maturity and therefore, they may already have bred fertile females. For sterilization programs to be effective, all non-breeding animals should be neutered prior to the onset of puberty, and compliance rates must be improved. Some animal shelters, in responding to these problems, have instituted early neuter programs. Under these programs, puppies and kittens are neutered before they leave the shelter, bringing compliance rates to 100 percent. Widespread adoption of early neuter programs by shelters will likely have a significant positive impact on the pet overpopulation problem. Since the advent of early neuter programs, a number of questions have been raised regarding the appropriate age at which gonadectomy should be performed, as well as the safety of anesthetizing young puppies. Data on gonadectomy in immature dogs have recently been published, including anesthetic and surgical techniques and effects on behavioral and physical development. One study7, comparing the effects of neutering puppies at seven weeks versus seven months of age, found that neutering at either age produced similar effects on physical, skeletal and behavioral development. Gonadectomy did not affect food intake or weight gain, once again arguing against the idea that neutering animals predisposes them to obesity. Neutering did not result in inactivity or lethargy in this study; in fact, all neutered dogs were assessed by their caretakers to be more active than their sexually intact counterparts. They also found that prepubertal gonadectomy does not stunt growth; indeed, it contributes to growth enhancement! Bone growth ceases when the physiologic growth plates located at the ends of immature bones "close." Growth plate closure of the radius and ulna (forelimb bones) occurred three months later (in seven-month-old neuters) to four months later (in seven-week-old neuters) in neutered puppies versus their sexually intact litter males. The result is that the forelimb bones of neutered puppies were a fraction of an inch longer than those of the unneutered pups. Also of significance is the fact that the seven-week-old puppies in this study tolerated anesthesia well. Surgeons actually found that spaying the younger puppies was easier than spaying bitches at the traditional age due to the smaller amount of fat, within the abdomen and the relative lack of vasculature. Surgical time and risk of hemorrhage were greatly reduced. The benefits of early neutering to dog breeders are obvious. By having pet quality puppies neutered before they leave for their new homes, breeders would no longer have to rely on their puppy buyers to carry out their wishes. Early neutering virtually guarantees that undesirable genes will not affect future generations, and it also pays heed to every responsible breeder's concern about the problem of pet overpopulation. Some shelters and veterinarians in private practice are currently performing the early neuter procedure. But it's also important for breeders to understand why individual veterinarians may choose not to perform early neuters. An eight-week-old puppy is not just a smaller version of an eight-month-old puppy. There are important differences between the two in factors such as respiratory and cardiovascular physiology, drug metabolism and thermoregulation. Few practitioners have accumulated a significant amount of experience in anesthetizing very young puppies on a regular basis, since there are not many situations which call for it. On the other hand, most practitioners have neutered many older puppies and young adults, feel comfortable with the anesthetic and surgical protocols they have developed, and may not want to change. These individuals may feel it is neither time- nor cost-efficient to develop new protocols for early neuters, unless they have a clientele composed substantially of breeders or other individuals who would be interested in such a program. In my experience as a veterinarian, I am often able to alleviate people's fears about neutering and clear up their misconceptions by presenting the objective data discussed here. Responsible breeders can—and should—make the same effort to ensure that pet puppies are neutered. Fulfillment of this duty brings all of us closer to breeding fewer dogs and conquering the pet overpopulation problem. Dog Owners' Observations Between 1974 and 1980, • thousands of 8 to 12-week-old puppies were neutered at the Medford, Oregon, SPCA shelter. Did early neutering cause long-term undesirable after effects, as some people believed? Shelter personnel decided to find out for themselves by looking at the dogs in their area. Questionnaires were sent out to owners of 200 randomly selected dogs aged 3 to 14 years that had been neutered when they were 6 to 12 weeks old. Identical questionnaires were also mailed to owners of 200 dogs that had not been neutered or had been neutered after 6 months of age. Their responses (see the charts at right) were published in an article by Leo L. Lieberman, D.V.M., in the Journal of the American Veterinary Medical Association on September 1, 1987. Owners of both male and female dogs in this survey reported less aggressive behavior, weight gain and medical problems for those dogs neutered at an early age, as compared to those dogs that were sexually intact or neutered after, six months.—Elizabeth Bodner, D.V.M. The results of the survey that asked owners to comment on after effects of neutering. Numbers on horizontal axis indicate: (1) owner not pleased; (2) undesirable sexual behavior of pet; (3) aggressive behavior of pet; (4) overweight pet; (5) medical problems with pet; (6) intelligence rating of pet. Taken from JAVMA, Vol. 191, No. 5, September 1, 1987. Dr. Bodner is the executive editor of the GAZETTE. References 1. Grandy JL, Dunlop CI. Anesthesia of pups and kittens. JAVMA 1991;198:1244-1249. 2. Hart BL. Effects of neutering and spaying on the behavior of dogs and cats: Questions and answers about practical concerns. JAVMA 1991;198:1204-1205. 3. Houpt KA. Coren B, Hintz et al. Effect of sex and reproductive status on sucrose preference, food intake, and body weight of dogs. JAVMA 1979; 174:1083-K185. 4. Johnston SD. Questions and answers on the effects of surgically neutering dogs and cats. JAVMA 1991; 198:1206-1213. 5. LeRoux PH. Thyroid status, oestradiol level, work performance and body mass of ovariectomised bitches and bitches bearing ovarian autotransplants in the stomach wall.JS Afr Vet Assoc 1977:48:115- 117. 6. Olson PN, Nett TM. Reproductive endocrinology and physiology of the bitch, in Morrow DA (ed.) Current Therapy in Theriogenology. 1986, W.B. Saunders, Philadelphia. 453-457. 7. Salmeri KR, Bloomberg MS, Scruggs SL, Shille V. Gonadectomy in immature dogs: Effects on skeletal, physical, and behavioral development. JAVMA 1991;198:1193-1203. 8. Salmeri KR, Olson PN, Bloomberg MS, Elective gonadectomy in dogs: A review. JAVMA 1991:198:1183-1191. 9. Johnston SD. Chapter 181, Male Reproductive System. In Slatter DH (ed.), Textbook of Small Animal Surgery, Volume 11. 1985, W. B. Saunders. Philadelphia. 2535-2545. 10. Thrusfield MV. Association between urinary incontinence and spaying in bitches. Vet Rec 1985,116:695. Dr. Marrion is affiliated with Angell Memorial Animal Hospital in Boston |
Quote:
http://www.akcchf.org/canine-health/...iosarcoma.html Canine Splenic Hemangiosarcoma: How a Simple Diagnostic Test May Save Lives Modiano Lab - Cancer Info - Hemangiosarcoma |
Quote:
|
Introduction In many parts of the world, due to cultural or economic prohibitions, bitches and dogs are not spayed or castrated unless they have reproductive tract disease. However, in the United States, virtually all bitches and dogs are rendered sterile by surgery at some point in their life. This better allows for reproduction control in animals no longer capable of or not considered desirable for breeding, and eliminates behaviors and physical changes related to presence of reproductive hormones that dog owners find objectionable. The surgeries most commonly performed are ovariohysterectomy (removal of the uterus and both ovaries), commonly called spaying, and castration (removal of both testes and the associated epididymes). Castration is commonly also called neutering, although that term most correctly can be used for surgery of either gender. Collectively, these surgeries can be referred to as gonadectomy, removal of the gonads or reproductive organs. Removal of the ovaries eliminates secretion of the hormones estrogen and progesterone. Removal of the testes eliminates secretion of the hormone testosterone. Elimination of these hormones obviously leads to decreases in behaviors and physical changes associated with their secretion, such as heat behavior, swelling of the vulva, and estrous bleeding in bitches, and mounting and roaming in dogs. However, reproductive hormones have effects on other tissues in the body and removal of those hormones may inadvertently impact those systems negatively. Other, less obvious, hormone changes also occur after gonadectomy, including persistent elevation in hormones that control the secretion of estrogen, progesterone, and testosterone. Whether these other hormone changes affect other systems positively or negatively often is unclear. This paper is a review of what has been demonstrated in the veterinary literature regarding effect of gonadectomy on the animal as a whole. This discussion does not address the societal problem of pet overpopulation. The author feels that animals with no owner or guardian should be spayed or castrated before adoption into a new home as one of many initiatives necessary to decrease the number of dogs euthanized in the United States annually. This discussion instead refers to dogs with responsible owners or guardians who maintain dogs as household pets, do not allow the animals to roam free, and provide the animals with regular veterinary care. Evidence in this context is defined as credible information from peer-reviewed research. Studies involving more dogs are more valuable than reports of single cases. Multiple studies documenting a given phenomenon are more valuable than single papers. Incidence in this context is reported as a percent; this is the number of affected animals out of a random sample of 100. In veterinary medicine, any condition with an incidence greater than 1% is considered common. Readers are encouraged to carefully read all manuscripts of interest and to ask their veterinarian for clarification if needed. This paper is condensed from a more detailed, extensively referenced manuscript that may be available through your veterinarian (Root Kustritz MV. Determining the optimal age for gonadectomy of dogs and cats. Journal of the American Veterinary Medical Association 2007;231(11):1665-1675). - See more at: Determining The Best Age At Which To Spay Or Neuter | AKC Canine Health Foundation 3 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
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 |
[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. |
[quote=gemy;4451171] Quote:
|
Quote:
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 :D), 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 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). |
Quote:
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! |
[quote=megansmomma;4451094] Quote:
|
Quote:
|
| All times are GMT -8. The time now is 10:56 AM. |
Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Copyright ©2003 - 2018 YorkieTalk.com
Privacy Policy - Terms of Use