Neutering, from the Latin neuter ('of neither sex'), [1] is the removal of a non-human animal's reproductive organ, either all of it or a considerably large part. The male-specific term is castration, while spaying is usually reserved for female animals. Colloquially, both terms are often referred to as fixing. [2] In male horses, castrating is referred to as gelding . An animal that has not been neutered is sometimes referred to as entire or intact.
Neutering is the most common method for animal sterilization. Humane societies, animal shelters, and rescue groups urge pet owners to have their pets neutered to prevent the births of unwanted litters, which contribute to the overpopulation of unwanted animals in the rescue system. Many countries require that all adopted cats and dogs be sterilized before going to their new homes.
Spaying is the surgical removal of the ovaries and sometimes uterus in female animals. It is commonly performed as a method of birth control and behavior modification. [3]
In non-human animals, the technical term is an ovo-hysterectomy or ovariohysterectomy; while in humans, this is called a hystero-oophorectomy. One form of spaying is to remove only the ovaries (oophorectomy or ovariectomy), which is mainly done in cats and young dogs as well as in laparoscopic procedures. Another, less commonly performed method is an "ovary-sparing spay" [4] in which the uterus is removed but one (or both) ovaries are left. A complete ovariohysterectomy may involve removal of the ovaries, uterus, oviducts, and uterine horns.
The surgery can be performed using a traditional open approach or by laparoscopic "keyhole" surgery. Open surgery is more widely available, as laparoscopic surgical equipment costs are expensive. Traditional open surgery is usually performed through a ventral midline incision below the umbilicus. The incision size varies depending upon the surgeon and the size of the animal. The uterine horns are identified and the ovaries are found by following the horns to their ends.
There is a ligament that attaches the ovaries to the body wall, which may need to be broken down so the ovaries can be identified. The ovarian arteries are then ligated with resorbable suture material and then the arteries transected. The uterine body (which is very short in litter-bearing species) and related arteries are also tied off just in front of the cervix (leaving the cervix as a natural barrier). The entire uterus and ovaries are then removed. The abdomen is checked for bleeding and then closed with a three-layer closure. The linea alba and then the subcutaneous layer are closed with resorbable suture material. The skin is then stapled, sutured, or glued closed. For suturing the feline linea alba, the most appropriate suture bite and stitch interval size was suggested to be 5 mm. [5]
Laparoscopic surgery is performed using a camera and instruments placed through small incisions (ports) in the body wall. The patient is under anaesthesia and lying on the back. The incisions are between 5 and 10 millimetres (0.20 and 0.39 in) and the number varies according to the equipment and technique used. The surgeon watches on a screen during the operation. The first port is made just behind the umbilicus and the camera is inserted. The abdomen is inflated with carbon dioxide gas to create a space in which to operate. A second port is introduced a few centimeters in front of the navel and a long grasping instrument called a Babcock forceps is inserted. The surgeon finds the ovary with the instrument and uses it to suspend the ovary from a needle placed through the abdominal wall. This lifts the ovary and uterus safely away from other organs. The surgeon then removes the grasping instrument and replaces it with an instrument that cauterizes and cuts tissue. This instrument uses electricity to heat the blood vessels to seal them and to cut them. No sutures are placed inside. The ovary is separated from the uterus and round ligament. The cautery instrument is removed and replaced by the grasping instrument, which is used to pull the ovary out through the small abdominal incision (port). This is repeated on the other side and the small holes are closed with a few sutures. Another method uses ligatures and even the uterus is removed. In female dogs only removing the ovaries and not the uterus is not state of the art because this way the risk of pyometra persists.
The benefits of laparoscopic surgery are less pain, faster recovery, and smaller wounds to heal. A study has shown that patients are 70% more active in the first three days post-surgery compared to open surgery. The reason open surgery is more painful is that larger incisions are required, and the ovary needs to be pulled out of the body, which stretches and tears tissue in the abdomen (it is not uncommon for patients to react under anaesthesia by breathing faster at this point).
Removing the ovaries in female dogs removes the production of progesterone, which is a natural calming hormone and a serotonin uplifter. Spaying may therefore escalate any observable aggressive behaviour, either to humans or other dogs. [6] [7] [8] [9]
The risk of infections, bleeding, ruptures, inflammation and reactions to the drugs given to the animal as part of the procedure are all possibilities that should be considered.
In male animals, castration involves the removal of the testes (testicles), and is commonly practiced on both household pets (for birth control and behaviour modification) and on livestock (for birth control, as well as to improve commercial value). Often the term neuter[ing] is used to specifically mean castration, e.g. in phrases like "spay and neuter".
Vasectomy: In a more delicate procedure than castration, the vasa deferentia – ducts that run from the testes to the penis – are cut then tied or sealed, to prevent sperm from entering into the urethra. Failure rates are insignificantly small. Breeders routinely have this procedure carried out on male ferrets and sheep to manipulate the estrus cycles of in-contact females. It is uncommon in other animal species. Because a vasectomy is usually a more expensive procedure, among pet-keepers it is more often performed on show animals, to cosmetically preserve their appearance (though depending upon the fancier organization, the procedure may invalidate the animal's candidacy for certain awards, or relegate it to a non-pedigree, generic "household pet" competition division, just as with full castration).
Tubal ligation: Snipping and tying of oviducts as a sterilization measure can be performed on female cats, dogs, and other species; it is essentially the female equivalent of vasectomy, but a more invasive procedure. Risk of unwanted pregnancies is insignificantly small. Only a few veterinarians perform the procedure.
Like other forms of neutering, vasectomy and tubal ligation eliminate the ability to produce offspring. They differ from neutering in that they leave the animal's levels and patterns of sex hormone unchanged. Both sexes will retain their normal reproductive behavior, and other than birth control, none of the advantages and disadvantages listed below apply. This method is favored by some people who seek minimal infringement on the natural state of companion animals to achieve the desired reduction of unwanted births of cats and dogs.
"Gomerization" is breeders' informal term for surgical techniques by which male livestock, such as bulls, retain their full libido (and related effects like sex pheromones that would be lost through castration), but are rendered incapable of copulation. This is done to stimulate and identify estrous females without the risk of transmitting venereal diseases or causing a pregnancy by a male other than the one intended for selective breeding. Animals altered for this purpose are referred to as teasers (teaser bulls, etc.), or gomers. Several methods are used. Penile translocation surgically alters the penis to point far enough away from its normal direction that it cannot manage vaginal penetration. Penile fixation permanently attaches the penis to the abdomen so that it cannot be lowered for penetration. Penectomy is the partial or complete removal of the penis. [20]
Early-age neutering, also known as pediatric spaying or prepubertal gonadectomy, is the removal of the ovaries or testes before the onset of puberty. It is used mainly in animal sheltering and rescue where puppies and kittens can be neutered before being adopted out, eliminating non-compliance with sterilization agreement, which is typically above 40%. [21] The American Veterinary Medical Association, American Animal Hospital Association and the Canadian Veterinary Medical Association support the procedure for population control, provided that the veterinarian uses their best knowledge when making the decision about the age at neutering. [22] [23] [24] A task force recommends that cats are spayed–neutered prior to 5 months of age. [25] [26]
While the age-unrelated risks and benefits cited above also apply to early-age neutering, various studies have indicated that the procedure is safe and not associated with increased mortality or serious health and behavioral problems when compared to conventional age neutering. [27] [28] [29] [30] [31] Anesthesia recovery in young animals is usually more rapid and there are fewer complications. [31] [32] One study found that in female dogs there is an increasing risk of urinary incontinence the earlier the procedure is carried out; the study recommended that female dogs be spayed no earlier than 3 to 4 months of age. [28] A later study comparing female dogs spayed between 4 and 6 months and after 6 months showed no increased risk. [33]
One study showed the incidence of hip dysplasia increased to 6.7% for dogs neutered before 5.5 months compared to 4.7% for dogs neutered after 5.5 months, although the cases associated with early age neutering seems to be of a less severe form. There was no association between age of neutering and arthritis or long-bone fractures. [28] Another study showed no correlation between age of neutering and musculoskeletal problems. [30] A study of large breed dogs with cranial cruciate ligament rupture associated early-age neutering with the development of an excessive tibial plateau angle. [34]
Of particular note are two recent studies from Lynette Hart's lab at UC Davis. The first study from 2013, published in a well-known interdisciplinary peer-reviewed journal demonstrated "no cases of CCL (cruciate ligament tear) diagnosed in intact males or females, but in early-neutered males and females the occurrences were 5 percent and 8 percent, respectively. Almost 10 percent of early-neutered males were diagnosed with LSA (lymphosarcoma), 3 times more than intact males. The percentage of HSA (hemangiosarcoma) cases in late-neutered females (about 8 percent) was 4 times more than intact and early-neutered females. There were no cases of MCT (mast cell tumor) in intact females, but the occurrence was nearly 6 percent in late-neutered females". [35]
The second study from 2014 [36] highlighted significant difference in closely related breeds (retrievers), suggesting that inter-breed variability is quite high and that sweeping legal measures and surgical mandates are not the best solutions to canine welfare and health. Specifically the study states: "In Labrador Retrievers, where about 5 percent of gonadally intact males and females had one or more joint disorders, neutering at 6 months doubled the incidence of one or more joint disorders in both sexes. In male and female Golden Retrievers, with the same 5 percent rate of joint disorders in intact dogs, neutering at 6 months increased the incidence of a joint disorder to 4–5 times that of intact dogs. The incidence of one or more cancers in female Labrador Retrievers increased slightly above the 3 percent level of intact females with neutering. In contrast, in female Golden Retrievers, with the same 3 percent rate of one or more cancers in intact females, neutering at all periods through 8 years of age increased the rate of at least one of the cancers by 3–4 times. In male Golden and Labrador Retrievers neutering had relatively minor effects in increasing the occurrence of cancers."
In terms of behavior in dogs, separation anxiety, aggression, escape behavior and inappropriate elimination are reduced while noise phobia and sexual behavior was increased. In males with aggression issues, earlier neutering may increase barking. [28] In cats, asthma, gingivitis, and hyperactivity were decreased, while shyness was increased. In male cats, occurrence of abscesses, aggression toward veterinarians, sexual behaviors, and urine spraying was decreased, while hiding was increased. [27]
![]() | This article contains a pro and con list .(April 2017) |
Besides being a birth control method, and being convenient to many owners, castrating/spaying has the following health benefits:
Various studies of the effects neutering has overall on male and female dog aggression have been unable to arrive at a consensus. A possible reason for this according to two studies is changes to other factors have more of an effect than neutering. [64] [65] One study reported results of aggression towards familiar and strange people and other dogs reduced between 10 and 60 percent of cases, [66] while other studies reported increases in possessive aggression [67] and aggression towards familiar and strange people, [68] and more studies reported there was no significant difference in aggression risk between neutered and non-neutered males. [65] [69] For females with existing aggression, many studies reported increases in aggressive behavior [6] [7] [8] [9] and some found increased separation anxiety behavior. [68] [70] A report from the American Kennel Club Canine Health Foundation reported significantly more behavioral problems in castrated dogs. The most commonly observed behavioral problem in spayed females was fearful behavior and the most common problem in males was aggression. [71] Early age gonadectomy is associated with an increased incidence of noise phobias and undesirable sexual behaviors[ clarify ]. [72]
A specialized vocabulary is used in animal husbandry and animal fancy for neutered (castrated) animals:
There are differing views in Islam with regard to neutering animals, with some Islamic associations stating that when done to maintain the health and welfare of both the animals and the community, neutering is allowed on the basis of being in the interest of 'maslaha' (general good) [78] or "choosing the lesser of two evils". [79]
Orthodox Judaism forbids the castration of both humans and non-human animals by Jews, [80] except in lifesaving situations. [81] In 2007, the Sephardic Chief Rabbi of Israel Rabbi Shlomo Amar issued a ruling stating that it is permissible to have companion animals neutered on the basis of the Jewish mandate to prevent cruelty to animals. [82]
The cat, also referred to as domestic cat or house cat, is a small domesticated carnivorous mammal. It is the only domesticated species of the family Felidae. Advances in archaeology and genetics have shown that the domestication of the cat occurred in the Near East around 7500 BC. It is commonly kept as a pet and farm cat, but also ranges freely as a feral cat avoiding human contact. Valued by humans for companionship and its ability to kill vermin, the cat's retractable claws are adapted to killing small prey like mice and rats. It has a strong, flexible body, quick reflexes, and sharp teeth, and its night vision and sense of smell are well developed. It is a social species, but a solitary hunter and a crepuscular predator. Cat communication includes vocalizations—including meowing, purring, trilling, hissing, growling, and grunting–as well as body language. It can hear sounds too faint or too high in frequency for human ears, such as those made by small mammals. It secretes and perceives pheromones.
A kitten is a juvenile cat. After being born, kittens display primary altriciality and are fully dependent on their mothers for survival. They normally do not open their eyes for seven to ten days. After about two weeks, kittens develop quickly and begin to explore the world outside their nest. After a further three to four weeks, they begin to eat solid food and grow baby teeth. Domestic kittens are highly social animals and usually enjoy human companionship.
Cryptorchidism, also known as undescended testis, is the failure of one or both testes to descend into the scrotum. The word is from Ancient Greek κρυπτός (kryptos) 'hidden' and ὄρχις (orchis) 'testicle'. It is the most common birth defect of the male genital tract. About 3% of full-term and 30% of premature infant boys are born with at least one undescended testis. However, about 80% of cryptorchid testes descend by the first year of life, making the true incidence of cryptorchidism around 1% overall. Cryptorchidism may develop after infancy, sometimes as late as young adulthood, but that is exceptional.
Hemangiosarcoma is a rapidly growing, highly invasive variety of cancer that occurs almost exclusively in dogs, and only rarely in cats, horses, mice, or humans. It is a sarcoma arising from the lining of blood vessels; that is, blood-filled channels and spaces are commonly observed microscopically. A frequent cause of death is the rupturing of this tumor, causing the patient to rapidly bleed to death.
Trap–neuter–return (TNR), also known as trap–neuter–release, is a controversial method that attempts to manage populations of feral cats. The process involves live-trapping the cats, having them neutered, ear-tipped for identification, and, if possible, vaccinated, then releasing them back into the outdoors. If the location is deemed unsafe or otherwise inappropriate, the cats may be relocated to other appropriate areas. Often, friendly adults and kittens young enough to be easily socialized are retained and placed for adoption. Feral cats cannot be socialized, shun most human interaction and do not fare well in confinement, so they are not retained. Cats suffering from severe medical problems such as terminal, contagious, or untreatable illnesses or injuries are often euthanized.
Pyometra or pyometritis is a uterine infection. Though it is most commonly known as a disease of the unaltered female dog, it is also a notable human disease. It is also seen in female cattle, horses, goats, sheep, swine, cats, rabbits, hamsters, ferrets, rats and guinea pigs. Pyometra is an important disease to be aware of for any dog or cat owner because of the sudden nature of the disease and the deadly consequences if left untreated. It has been compared to acute appendicitis in humans, because both are essentially empyemas within an abdominal organ.
A feral cat or a stray cat is an unowned domestic cat that lives outdoors and avoids human contact; it does not allow itself to be handled or touched, and usually remains hidden from humans. Feral cats may breed over dozens of generations and become an aggressive local apex predator in urban, savannah and bushland environments. Some feral cats may become more comfortable with people who regularly feed them, but even with long-term attempts at socialization, they usually remain aloof and are most active after dusk. Of the 700 million cats in the world, an estimated 480 million are feral.
Dog aggression expressed by dogs is considered to be normal behaviour and various types of aggression are influenced by a dog's environment and genetic predisposition. Dogs commonly display possessive aggression when defending resources or themselves.
In mammalian species, pseudopregnancy is a physical state whereby all the signs and symptoms of pregnancy are exhibited, with the exception of the presence of a fetus, creating a false pregnancy. The corpus luteum is responsible for the development of maternal behavior and lactation, which are mediated by the continued production of progesterone by the corpus luteum through some or all of pregnancy. In most species, the corpus luteum is degraded in the absence of a pregnancy. However, in some species, the corpus luteum may persist in the absence of pregnancy and cause "pseudopregnancy", in which the female will exhibit clinical signs of pregnancy.
The Dobermann is a German breed of medium-large working dog of pinscher type. It was originally bred in Thuringia in about 1890 by Louis Dobermann, a tax collector. It has a long muzzle and – ideally – an even and graceful gait. The ears were traditionally cropped and the tail docked, practices which are now illegal in many countries.
The health of dogs is a well studied area in veterinary medicine.
A mammary tumor is a neoplasm originating in the mammary gland. It is a common finding in older female dogs and cats that are not spayed, but they are found in other animals as well. The mammary glands in dogs and cats are associated with their nipples and extend from the underside of the chest to the groin on both sides of the midline. There are many differences between mammary tumors in animals and breast cancer in humans, including tumor type, malignancy, and treatment options. The prevalence in dogs is about three times that of women. In dogs, mammary tumors are the second most common tumor over all and the most common tumor in female dogs with a reported incidence of 3.4%. Multiple studies have documented that spaying female dogs when young greatly decreases their risk of developing mammary neoplasia when aged. Compared with female dogs left intact, those spayed before puberty have 0.5% of the risk, those spayed after one estrous cycle have 8.0% of the risk, and dogs spayed after two estrous cycles have 26.0% of the risk of developing mammary neoplasia later in life. Overall, unspayed female dogs 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 female dogs even up to 9 years of age. There is a much lower risk in male dogs and a risk in cats about half that of dogs.
The dog is a domesticated descendant of the wolf. Also called the domestic dog, it was selectively bred from an extinct population of wolves during the Late Pleistocene by hunter-gatherers. The dog was the first species to be domesticated by humans, over 14,000 years ago and before the development of agriculture. Experts estimate that due to their long association with humans, dogs have gained the ability to thrive on a starch-rich diet that would be inadequate for other canids.
Veterinary surgery is surgery performed on non-human animals by veterinarians, whereby the procedures fall into three broad categories: orthopaedics, soft tissue surgery, and neurosurgery. Advanced surgical procedures such as joint replacement, fracture repair, stabilization of cranial cruciate ligament deficiency, oncologic (cancer) surgery, herniated disc treatment, complicated gastrointestinal or urogenital procedures, kidney transplant, skin grafts, complicated wound management, and minimally invasive procedures are performed by veterinary surgeons. Most general practice veterinarians perform routine surgeries such as neuters and minor mass excisions; some also perform additional procedures.
Canine reproduction is the process of sexual reproduction in domestic dogs, wolves, coyotes and other canine species.
Aging in dogs varies from breed to breed, and affects the dog's health and physical ability. As with humans, advanced years often bring changes in a dog's ability to hear, see, and move about easily. Skin condition, appetite, and energy levels often degrade with geriatric age. Medical conditions such as cancer, kidney failure, arthritis, dementia, and joint conditions, and other signs of old age may appear.
Cancer is the leading cause of death in dogs. It is estimated that 1 in 3 domestic dogs will develop cancer, which is the same incidence of cancer among humans. Dogs can develop a variety of cancers and most are very similar to those found in humans. Dogs can develop carcinomas of epithelial cells and organs, sarcomas of connective tissues and bones, and lymphomas or leukemias of the circulatory system. Selective breeding of dogs has led certain pure-bred breeds to be at high-risk for specific kinds of cancer.
Pediatric spaying or neutering is defined as performing an ovariohysterectomy (spaying) or orchidectomy on a kitten or puppy between the ages of 6 and 14 weeks. Spaying and neutering are sterilization procedures which prevent the animals from reproducing. The procedures are also referred to as “gonadectomies” in the veterinary literature.
Rage syndrome is a rare seizure disorder in dogs, characterized by explosive aggression.
Non-surgical fertility control is the prevention of reproduction without the use of surgery. The most common form of sterilization in dogs and cats is surgical, spaying in females and castration in males. Non-surgical fertility control can either result in sterilization or temporary contraception and could offer a cheaper way to keep wild dog and cat populations under control. As of 2019, only contraceptives are commercially available. Research is ongoing into methods that could result in permanent suppression of fertility.