Castration (also known as gonadectomy) is any action, surgical, chemical, or otherwise, by which an individual loses use of the testicles. Surgical castration is bilateral orchiectomy (excision of both testes), and chemical castration uses pharmaceutical drugs to inactivate the testes. Castration causes sterilization (preventing them from reproducing); it also greatly reduces the production of certain hormones, such as testosterone. Surgical castration in animals is often called neutering.
- Non Han peoples
- Slave trade
- Trafficking of boys for prostitution in modern times
- Preventive measure
- Medical consequences
- Psychoanalysis and literary theory
- Chemical castration
- Parasitic infection
The term "castration" is sometimes also used to refer to the removal of the ovaries in the female, otherwise known as an oophorectomy or, in animals, spaying. Estrogen levels drop precipitously following oophorectomy, and long-term effects of the reduction of sex hormones are significant throughout the body.
Castration of non-human animals is intended to favour a desired development of the animal or of its habits or to prevent overpopulation.
Castration was frequently used for religious or social reasons in certain cultures in Europe, South Asia, Africa, and East Asia. After battles in some cases, winners castrated their captives or the corpses of the defeated to symbolize their victory and seize their "power". Castrated men — eunuchs – were often admitted to special social classes and were used particularly to staff bureaucracies and palace households: in particular, the harem. Castration also figured in a number of religious castration cults. Other religions, such as Judaism, were strongly opposed to the practice. The Leviticus Holiness code, for example, specifically excludes eunuchs or any males with defective genitals from the priesthood, just as castrated animals are excluded from sacrifice.
Eunuchs in China had been known to usurp power in many eras of Chinese history, most notably in the Later Han, late Tang and late Ming dynasties. There are similar recorded Middle Eastern events.
In ancient times, castration often involved the total removal of all the male genitalia. This involved great danger of death due to bleeding or infection and, in some states, such as the Byzantine Empire, was seen as the same as a death sentence. Removal of only the testicles had much less risk.
Either surgical removal of both testicles or chemical castration may be carried out in the case of prostate cancer. Testosterone-depletion treatment (either surgical removal of both testicles or chemical castration) is used to slow down the cancer, greatly reduce sex drive or interest in those with sexual drives, obsessions, or behaviors, or any combination of those that may be considered deviant. Castration in humans has been proposed, and sometimes used, as a method of birth control in certain poorer regions.
Castration has also been used in the United States for sex offenders to ensure they will not commit such crimes ever again.
Trans women often undergo orchiectomy, as do some other transgender people. Orchiectomy may be performed as part of a more general sex reassignment surgery, either before or during other procedures. It may also be performed on someone who does not desire, or cannot afford, further surgery.
Involuntary castration appears in the history of warfare, sometimes used by one side to torture or demoralize their enemies. It was practiced to extinguish opposing male lineages and thus allow the victor to sexually possess the defeated group's women.
Another famous victim of castration was the medieval French philosopher, scholar, teacher, and (later) monk Pierre Abélard. He was castrated by relatives of his lover, Héloïse.
Bishop Wimund, a 12th-century English adventurer and invader of the Scottish coast, was castrated.
William Wallace, the Scottish resistance leader, was castrated as part of his execution, for resistance to English rule.
Wim Deetman was criticized by the Dutch parliament for excluding evidence of castration in his report on sexual abuse by the Roman Catholic Church, where ten children were allegedly "punished" by castration in the 1950s for reporting sexual abuse by Roman Catholic priests. However, the Deetman Commission had rejected it as the person who reported the incident admitted it was speculative. Voluntary castration for homosexuality was also state policy in Netherlands at that point, as well against Catholic canon law, and there has been no evidence suggesting the Church had a part in organizing the procedures. Chemical castration has been and is used as part of sentencing in criminal cases.
In 1952, Alan Turing–the father of computer science and also the inventor of Turing machine–was criminally prosecuted for homosexual acts and chose chemical castration as an alternative to a period of imprisonment.
According to legend, during the reign of the legendary Emperor Shun and Yu in China, in 2281 BCE castration was passed into law as a punishment, which remained so until the reign of Gaozu of Tang (589–600 AD). However, it was still practiced after his reign. According to historians, it was incorporated into Chinese law during the Zhou Dynasty. It was one of the five physical punishments that could be legally inflicted on criminals in China.
Records of castrations in China date to the Shang dynasty (ca.1700–1050 BCE), when the Shang kings castrated prisoners of war.
During the reign of Mu of the Zhou Dynasty (10th c. BCE) the Minister of Crime, Marquis Lu, reformed the law in 950 BC to make it easier for people to be sentenced to castration instead of death. As long as the practice existed in China, not only were the testicles merely removed but castration included the severing of one's entire genitalia. Both organs were cut off with a knife at the same time.
Men were castrated and made into state slaves during the Qin dynasty (221–206 BCE) to perform forced labor for projects such as the Terracotta Army. The Qin government confiscated the property and enslaved the families of rapists who received castration as a punishment. Men punished with castration during the Han dynasty were also used as slave labor.
In the Han dynasty (206 BCE–220 CE), castration continued to be used as a punishment for various offences. Sima Qian, the famous Chinese historian, was castrated by order of the Han Emperor of China for dissent. In another incident multiple people, including a chief scribe and his underlings, were subjected to castration.
When the Chinese overthrew Mongol rule, many Mongols were castrated and turned into eunuchs. When the Ming army finally captured Yunnan from Mongols in 1382, thousands of prisoners were killed and, according to the custom in times of war, their young sons–including Zheng He–were castrated.
At the end of the Ming Dynasty, there were about 70,000 eunuchs (宦官 huànguān, or 太監 tàijiàn) employed by the emperor, with some serving inside the Forbidden City.
Many of the non-Han Chinese peoples who founded states in China after invading originally did not have eunuchs as part of their culture, but adopted it from the Han Chinese.
The Khitan people adopted the practice of using eunuchs from the Chinese and the eunuchs used were non-Khitan prisoners of war. The Khitan were a nomadic Mongolic people and originally did not have eunuchs as part of their culture. When the Khitan founded the Liao Dynasty they developed a harem system with concubines and wives and adopted eunuchs as part of it. All of the eunuchs were captured ethnic Chinese from the Central Plains that came from two sources. The Khitan captured Chinese people who were already eunuchs at the Jin court when they invaded of the Later Jin. Another source was during their war with the Chinese Song dynasty, the Khitan would raid China, capture Han Chinese boys as prisoners of war and emasculate them to become eunuchs. The emasculation of captured Chinese boys guaranteed a continuous supply of eunuchs to serve in the Liao Dynasty harem. The Empress Dowager Chengtian played a large role in the raids to capture and emasculate the boys.
The Khitan Empress Dowager Xiao Chuo (Chengtian) of the Khitan Liao state took power at age 30 in 982 as a regent for her son. She personally led her own army against the Song Chinese in 986 and defeated them in battle, fighting the retreating Chinese army. She then ordered the castration of around 100 ethnic Chinese boys she had captured in China, supplementing the Khitan's supply of eunuchs to serve at her court, among them was Wang Ji'en. The boys were all under ten years old and were selected for their good looks.
The History of Liao 遼史 described and praised Empress Chengtian's capture and mass castration of Chinese boys in a biography on the Chinese eunuch Wang Ji'en.
Some legends say that the Mongol Genghis Khan was castrated by a Tangut princess using a knife, who wanted revenge against his treatment of the Tanguts and to stop him from raping her.
During the Qing (Manchu) dynasty (1644–1911 CE), the sons and grandsons of the rebel Yaqub Beg in China were all sentenced to castration. Surviving members of Yaqub Beg's family included his 4 sons, 4 grandchildren (2 grandsons and 2 granddaughters), and 4 wives. They either died in prison in Lanzhou, Gansu, or were killed by the Chinese. His sons Yima Kuli, K'ati Kuli, Maiti Kuli, and grandson Aisan Ahung were the only survivors in 1879. They were all underage children, and put on trial, sentenced to an agonizing death if they were complicit in their father's rebellious "sedition", or if they were innocent of their fathers crimes, were to be sentenced to castration and serving as a eunuch slave to Chinese troops, when they reached 11 years old, and handed over to the Imperial Household to be executed or castrated. Although some sources assert that the sentence of castration was carried out, official sources from the U.S. State Department and activists involved in the incident state that Yaqub Beg's son and grandsons had their sentence commuted to life imprisonment with a fund provided for their support. The last remaining Imperial eunuch, Sun Yaoting, died in 1996.
The eunuchs of Korea, called Naesi (내시, 內侍), were officials to the king and other royalty in traditional Korean society. The first recorded appearance of a Korean eunuch was in Goryeosa ("History of Goryeo"), a compilation about the Goryeo period. In 1392, with the founding of the Joseon Dynasty, the Naesi system was revised, and the department was renamed the "Department of Naesi" (내시부, 內侍府).
The Naesi system included two ranks, those of Sangseon (상선, 尙膳, "Chief of Naesi"), who held the official title of senior second rank, and Naegwan (내관, 內官, "Common official naesi"), both of which held rank as officers. 140 naesi in total served the palace in Joseon Dynasty period. They also took the exam on Confucianism every month. The naesi system was repealed in 1894 following Gabo reform.
According to legend, castration consisted of daubing a boy's genitals with human feces and having a dog bite them off. During the Yuan Dynasty, eunuchs became a desirable commodity for tributes, and dog bites were replaced by more sophisticated surgical techniques.
The Vietnamese adopted the eunuch system and castration techniques from China. Records show that the Vietnamese created eunuchs through castration in a painful procedure by removing the entire genitalia with both penis and testicles being cut off with a sharp knife or metal blade. The procedure was agonizing since the entire penis was cut off. The young man's thighs and abdomen would be tied and others would pin him down on a table. The genitals would be sterilized with pepper water and then cut off. A tube would be then inserted into the urethra to allow urination during healing. Any facial hair such as the beard would fall off and the eunuch's voice would become like a girl's. The eunuchs served as slaves to the Vietnamese palace women in the harem like the consorts, concubines, maids, Queen, and Princesses, doing most of the work. The only man allowed in the Palace was the Emperor, the only others allowed were his women and the eunuchs since they were not able to have sexual relations with the women. The eunuchs were assigned to do work for the palace women like massaging and applying make up to the women and preparing them for sex with the Emperor.
Lý Thường Kiệt was a prominent eunuch general during the Lý Dynasty (1009–1225).
The Trần Dynasty sent Vietnamese boy eunuchs as tribute to Ming Dynasty China several times, in 1383, 1384 and 1385 Nguyen Dao, Nguyen Toan, Tru Ca, and Ngo Tin were among several Vietnamese eunuchs sent to China.
During the Fourth Chinese domination of Vietnam, the Ming Chinese under the Yongle Emperor castrated many young Vietnamese boys, choosing them for their handsomeness and ability, and brought them to Nanjing to serve as eunuchs. Among them were the architect-engineer Nguyễn An and Nguyen Lang (阮浪). Vietnamese were among the many eunuchs of different origins found at Yongle's court. Among the eunuchs in charge of the Capital Battalions of Beijing was Xing An, a Vietnamese.
In the Lê Dynasty the Vietnamese Emperor Lê Thánh Tông was aggressive in his relations with foreign countries including China. A large amount of trade between Guangdong and Vietnam happened during his reign. Early accounts recorded that the Vietnamese captured Chinese whose ships had blown off course and detained them. Young Chinese men were selected by the Vietnamese for castration to become eunuch slaves to the Vietnamese. It has been speculated by modern historians that the Chinese who were captured and castrated by the Vietnamese were involved in trade between China and Vietnam instead of actually being blown off course by the wind and they were punished as part of a crackdown on foreign trade by Vietnam.
Several Malay envoys from the Malacca sultanate were attacked and captured in 1469 by the Lê Dynasty of Annam (Vietnam) as they were returning to Malacca from China. The Vietnamese enslaved and castrated the young from among the captured.
A 1472 entry in the Ming Shilu reported that when some Chinese from Nanhai county escaped back to China after their ship had been blown off course into Vietnam, where they had been forced to serve as soldiers in Vietnam's military. The escapees also reported that they found out up to 100 Chinese men remained captives in Vietnam after they were caught and castrated by the Vietnamese after their ships were blown off course into Vietnam. The Chinese Ministry of Revenue responded by ordering Chinese civilians and soldiers to stop going abroad to foreign countries. China's relations with Vietnam during this period were marked by the punishment of prisoners by castration.
A 1499 entry in the Ming Shilu recorded that 13 Chinese men from Wenchang including a young man named Wu Rui were captured by the Vietnamese after their ship was blown off course while traveling from Hainan to Guangdong's Qin subprefecture (Qinzhou), after which they ended up near the coast of Vietnam, during the Chenghua Emperor's rule (1447–1487). Twelve of them were enslaved to work as agricultural laborers, while the youngest, Wu Rui (吳瑞) was selected for castration since he was the only young man and he became a eunuch attendant at the Vietnamese imperial palace in Thang Long. After years of service, he was promoted at the death of the Vietnamese ruler in 1497 to a military position in northern Vietnam. A soldier told him of an escape route back to China and Wu Rui escaped to Longzhou. The local chief planned to sell him back to the Vietnamese, but Wu was rescued by the Pingxiang magistrate and then was sent to Beijing to work as a eunuch in the palace.
The Đại Việt sử ký toàn thư records that in 1467 in An Bang province of Dai Viet (now Quảng Ninh Province) a Chinese ship blew off course onto the shore. The Chinese were detained and not allowed to return to China as ordered by Le Thanh Tong. This incident may be the same one where Wu Rui was captured.
In the Nguyễn Dynasty the poet Hồ Xuân Hương mocked eunuchs in her poem as a stand-in for criticizing the government.
Commoners were banned from undergoing castration in Vietnam, only adult men of high social rank could be castrated, most eunuchs were born as such with a congenital abnormality. The Vietnamese government mandated that boys born with defective genitalia were to be reported to officials, in exchange for the town being freed from mandatory labor requirements. The boy would have the option of serving as a eunuch official or serving the palace women when he became ten years old. This law was put in place in 1838 during the Nguyễn Dynasty. The only males allowed inside the Forbidden City at Huế were the Emperor and his eunuchs.
The presence of eunuchs in Vietnam was used by the French colonizers to degrade the Vietnamese.
In 1778, Thomas Jefferson wrote a bill in Virginia reducing the punishment for rape, polygamy or sodomy from death to castration.
Aqa Mohammad Khan Qajar, who established the Qajar Dynasty in Iran (in the 18th century), was a victim of castration by officers of the previous kingdom. When he conquered Lotf Ali Khan, the last king of the Zand Dynasty, Qajar had Lotf Ali Khan castrated in revenge.
In the over 13 centuries of the Arab slave trade in Africa unknown number of Africans were enslaved and shipped to the Middle East. It is claimed that a vast majority of the male black slaves, estimated at around 80%, were castrated. European slaves were also castrated, often by non-Muslims in order to bypass Islamic prohibitions. European "castration centers" existed in Central Europe and other areas beyond Islamic rule, from which eunuchs were then imported.
"The Caliphate in Baghdad at the beginning of the 10th Century had 7,000 black eunuchs and 4,000 white eunuchs in his palace." The Arab slave trade typically dealt in the sale of castrated male slaves. Black boys at the age of eight to twelve had their scrotum and penis completely amputated. Around 9 out of 10 bled to death during the procedure, but the high price brought by eunuchs on the market made the practice profitable.
Trafficking of boys for prostitution in modern times
An article in the Gulf Times revealed in 2005 a major sex trade in mostly Nepalese boys who were lured to India and sold to brothels in Mumbai, Hyderabad, New Delhi, Lucknow and Gorakhpur. One victim was lured from Nepal at the age of 14, sold into slavery, locked up, beaten, starved, and forcibly castrated. He reported that he was held in a brothel with 40 to 50 other boys, many of whom were also castrated. He escaped and made his way back to Nepal. Two non-governmental organizations, one that works with homosexuals in Nepal, and one that works to rescue and rehabilitate trafficked women and children, were co-operating to help and rescue these boys.
"Voluntary" chemical or surgical castration has been in practice in many countries — reports are available from American and European countries in particular for over eighty years (chemical for circa thirty)— as an option for treatment for people who have broken laws of a sexual nature, allowing them to return to the community from otherwise lengthy detentions. The effectiveness and ethics of this treatment are heavily debated.
A temporary "chemical castration" has been studied and developed as a preventive measure and punishment for several repeated sex crimes, such as rape or other sexually related violence. This has also been used to punish homosexuality, such as the punishment suffered by Alan Turing.
In modern times, the Czech Republic practices surgically castrating convicted sex offenders. According to the reports compiled by Council of Europe, a human-rights forum, the central European country physically castrated at least 94 prisoners in the 10 years up to April 2008. The Czech Republic defends this procedure as voluntary and effective. According to Dr. Martin Hollý, director of the Psychiatric Hospital Bohnice in Prague, none of the nearly 100 sex offenders who had been physically castrated had committed further offences. One serial offender stated that being castrated was the "best decision" he ever made: "On the one hand you have to protect the potential victims and on the other hand I wanted to be protected from myself, I wanted to live like a normal person." Don Grubin, a professor at Newcastle University's Institute of Neuroscience who also runs a chemical castration program backed by the U.K.'s Ministry of Justice, was initially opposed to physical castration. After visiting the Czech Republic, however, he agreed that some form of castration might be of benefit to some sex offenders.
In Europe, when women were not permitted to sing in church or cathedral choirs in the Roman Catholic Church, boys were castrated to prevent their voices breaking at puberty and to develop a special high voice. The first documents mentioning castrati are Italian church records from the 1550s. In the baroque and classical music eras these singers were highly appreciated by opera composers as well. Mozart's Exultate Jubilate, Allegri's Miserere and other famous pieces from this period now sung by sopranos and countertenors were written for castrati. Some of the alto parts of Handel's Messiah were first sung by a castrato. Famous castrati include Farinelli, Senesino, Carestini, and Caffarelli. The last true castrato was Alessandro Moreschi (1858–1922) who served in the Sistine Chapel Choir. It was not until the late 19th century that the Roman Catholic Church officially condemned the production of castrati. In Modern times, the Mexican Javier Medina is the only professional opera singer that can perform as a castratti, since he suffered from an involuntary chemical castration, as a result from a cancer treatment that he had before he reached puberty.
A number of religions have included castration as a central theme of their practice. These include:
While castration is not a major part of Christianity, Jesus himself acknowledged in a discussion about avoiding adultery and divorce that some are involuntarily castrated or born that way, while some others "make themselves eunuchs" willingly out of a desire to be chaste Matthew 19:1–12. Given Jesus' frequent use of metaphor and hyperbole, e.g. Luke 9:62, the church has broadly discouraged any understanding of this passage as recommending literal "self-castration". That is consistent with Jesus' claims (as a rabbi) to uphold the Law given to Moses, e.g. Matthew 5:17, a Law which also discouraged literal castration Deut 23:1. However, in his own comments Jesus had no condemnation for any of the above. In Acts 8:34–8:39, a eunuch is baptized by Philip the Evangelist, demonstrating acceptance of castrated individuals in his church.
The first canon of the First Council of Nicaea in 325 AD forbid clergy members to voluntarily castrate themselves "when in perfect health", but freely accepted those who had been either castrated by others against their will, castrated due to a medical sickness or necessity, or those born as eunuchs.
Paul, arguing against circumcision in Galatians 5:12, says As for those agitators, I wish they would go the whole way and emasculate themselves! (NIV)
Well-known Christian eunuchs (or alleged eunuchs) include:
Judaism strictly forbids the castration of either humans or animals. While Deuteronomy 23:1 expels castrated men from the assembly of Israel; it means they are forbidden to marry or if married must divorce from their wives (though permitting the castrated to marry or remain married to female converts to Judaism). The laws of castration including cases of irreversible or unreversed vasectomy and all other cases where the flow of sperm is known to have been placed into a permanent state of dysfunction with either no hope or no desire to take the steps to repair. This interpitation reinforced by Isaiah 56:3–5 lovingly encouraging eunuchs who follow after God's laws.
According to Rashi, Kham (Ham) castrated his father Noah.
In Judaism, castrated animals are deemed unfit for sacrifice in the Temple (Lev 22:24). Castrated members of the priestly caste are forbidden to enter certain parts of the temple, to approach the altar, or to make sacrifices, although they could eat their share of the offerings and receive the priestly and Levite gifts (Lev. 21:16–24).
A subject of castration who is altered before the onset of puberty will retain a high voice, non-muscular build, and small genitals. He may well be taller than average, as the production of sex hormones in puberty — more specifically, estrogen via aromatization of testosterone — stops long bone growth. The person may not develop pubic hair and will have a small sex drive or none at all.
Castrations after the onset of puberty will typically reduce the sex drive considerably or eliminate it altogether. Castrated people are automatically sterile, because the testes (for males) and ovaries (for females) produce sex cells needed for sexual reproduction. Once removed the subject is infertile. The voice does not change. Some castrated people report mood changes, such as depression or a more serene outlook on life, although this might not be due to chemical changes but instead emotional changes due to the implications of the procedure. Body strength and muscle mass can decrease somewhat. Body hair may sometimes decrease. Castration prevents male pattern baldness if it is done before hair is lost. However, castration will not restore hair growth after hair has already been lost due to male pattern baldness.
Historically, many eunuchs who additionally underwent a penectomy reportedly suffered from urinary incontinence associated with the removal of the penis.
Without hormone replacement therapy (HRT), typical symptoms (similar to those experienced by menopausal women) include hot flashes, gradual bone-density loss resulting in osteopenia or osteoporosis, and potential weight gain or redistribution of body fat to the hips/chest. Replacement of testosterone in the form of gel, patches, or injections can largely reverse these effects, although breast enlargement has also been reported as a possible side effect of testosterone usage.
A study conducted at a mental institution in Kansas, where a large number of male inmates had been castrated, found that the eunuchs lived an average of 14 years longer than the uncastrated men. A similar study of 81 historical eunuchs in Korea's royal court found a 14 to 19 year increase in lifespan compared to intact men of similar socioeconomic background; these eunuchs had a centenarian rate of over 3%.
Psychoanalysis and literary theory
The concept of castration plays an important role in psychoanalysis; see, for example, castration anxiety.
In Mexican thriller La Casa del Pelícano, castration is shown as being connected to the Oedipus complex.
In the case of chemical castration, ongoing regular injections of anti-androgens are required. Chemical castration does not actually remove the testicles or ovaries of the subject, nor is it a form of sterilization.
Chemical castration seems to have a greater effect on bone density than physical castration. Since the development of teriparatide, this severe bone loss has been able to be reversed in nearly every case. At this time there is a limitation on the use of this medication to 24 months until the long-term use is better evaluated.
With the advent of chemical castration, physical castration is not generally recommended by the medical community unless medically necessary or desired, though some have undergone the procedure voluntarily.
Humans commonly castrate domestic animals not intended for breeding. Domestic animals are usually castrated to avoid unwanted or uncontrolled reproduction; to reduce or prevent other manifestations of sexual behaviour such as defending the herd from humans and other threats, or intra-herd aggression (e.g. fighting between groups of entire (uncastrated) males of a species); or to reduce other consequences of sexual behavior that may make animal husbandry more difficult, such as boundary/fence/enclosure destruction when attempting to get to nearby females of the species.
Male horses are usually castrated (gelded) using emasculators, because stallions are rather aggressive and troublesome. The same applies to male mules, although they are sterile. Male cattle are castrated to improve fattening and docility in feedlots or for use as oxen. Breeding individuals are kept entire and used for breeding: they may fetch higher prices when sold.
Livestock may be castrated when used for food to increase growth or weight or both of individual male animals and because of the undesirable taste and odor of the meat from sexually mature males. In domestic pigs the taint, called boar taint, is caused by androstenone and skatole concentrations stored in the fat tissues of the animal after sexual maturity. Boar taint is only found in a small minority of pigs and can be controlled through breeding selection, diet and management. It is released when the fat is heated and has a distinct odor and flavor that is widely considered unpalatable to consumers. Consequently, in commercial meat production, male pigs are either castrated shortly after birth or slaughtered before they reach sexual maturity. Recent research in Brazil has shown that castration of pigs is unnecessary because most pigs do not have the 'boar taint'. This is due to many breeds of pigs simply not having the heredity for the boar taint and the fact that pigs are normally slaughtered at a young market weight.
In the case of pets, castration is usually called neutering, and is encouraged to prevent overpopulation of the community by unwanted animals, and to reduce certain diseases such as prostate disease and testicular cancer in male dogs (oophorectomy in female pets is often called spaying). Testicular cancer is rare in dogs, but prostate problems are somewhat common in unaltered male dogs when they get older. Neutered individuals have a much lower risk of developing prostate problems in comparison. Unaltered male cats are more likely to develop an obstruction in their urethra, preventing them from urinating to some degree; however, neutering does not seem to make much difference statistically because many neutered toms also have the problem. A specialized vocabulary has arisen for neutered animals of given species:
An incompletely castrated male in livestock species (horse and cattle) is known as a rig.
The term stag is used for a male animal castrated after the secondary sex characteristics have developed to such a point as to give him the appearance of sexual maturity.
Methods of veterinary castration include instant surgical removal, the use of an elastrator tool to secure a band around the testicles that disrupts the blood supply, the use of a Burdizzo tool or emasculators to crush the spermatic cords and disrupt the blood supply, pharmacological injections and implants and immunological techniques to inoculate the animal against his own sexual hormones.
Certain animals, like horses and swine, are usually surgically treated with a scrotal castration (which can be done with the animal standing while sedated and after local anesthetic has been applied), while others, like dogs and cats, are anesthetised and recumbent when surgically castrated with a pre-scrotal incision in the case of dogs, or a pre-scrotal or scrotal incision used for cats.
In veterinary practice an "open" castration refers to a castration in which the inguinal tunic is incised and not sutured. A "closed" castration refers to when the procedure is performed so that the inguinal tunic is sutured together after incision.
Some parasitic nematodes chemically castrate their hosts. For example, Microphallus pseudopygmaeus chemically castrates its host, the snail Onoba aculeus, and causes it to grow larger than normal.