Topic:Castration
Castration in horses is a surgical procedure that involves the removal of the testicles, primarily performed to reduce aggressive behavior and prevent breeding. This operation, typically conducted on young male horses, or colts, can be done using various techniques, including open, closed, or laparoscopic methods. The procedure is generally carried out under anesthesia and requires post-operative care to minimize complications such as infection, swelling, or hemorrhage. Castration can influence a horse's physiology and behavior, often resulting in calmer temperaments and easier handling. This page offers a collection of peer-reviewed research studies and scholarly articles that explore the methodologies, physiological impacts, and behavioral changes associated with castration in equines.
Laparoscopic intra-abdominal ligation of the testicular artery following castration in a horse. A 364-kg (800-lb) 1-year-old mixed-breed horse was admitted for treatment of uncontrolled bleeding after castration. Multiple attempts to ligate the testicular artery through the scrotal incisions prior to referral had been unsuccessful. Because of the owner's concerns about cost, an attempt was made to control the bleeding by applying pressure to the inguinal region and administering formalin IV. However, hemorrhage continued. A decision was made to use laparoscopy to ligate the testicular artery. The horse was anesthetized and positioned in dorsal recumbency, and a routine ventral laparoscop...
Pituitary response to steroid replacement therapy in fertile, subfertile and infertile stallions after castration. Recent studies in our laboratory investigating plasma gonadotrophin concentrations before and after castration indicate that the hypothalamic-pituitary axis is not the original site of dysfunction in stallions with idiopathic infertility. In the present study, fertile, subfertile and infertile stallions were subjected to replacement therapy with oestradiol and testosterone 1 year after castration to investigate hypothalamic-pituitary axis function further. Fertile (n=5), subfertile (n=3) and infertile (n=2) castrated stallions of Light horse breeds, aged 11-23 years, were given either oestradi...
Testicular and hormonal changes in stallions with thermally induced testicular degeneration. The scrota of three Pony stallions and one miniature horse were insulated for 36 h. Plasma testosterone concentrations decreased gradually and were significantly (P < 0.05) lower than pretreatment values at 16, 24, 30, 38 and 44 h after onset of scrotal insulation. Plasma LH and oestradiol concentrations were significantly (P < 0.05) decreased 18 h, and 24 and 26 h, after onset of scrotal insulation, respectively. Plasma FSH concentrations were significantly (P < 0.05) decreased 4 days after the insulation was removed. Decreases in the potential daily sperm output per Pony for early p...
Testicular biopsy in stallions: diagnostic potential and effects on prospective fertility. Testicular biopsy was performed as a standing procedure on fertile, mature stallions (n=7) under sedation and local anaesthesia. The 'Biopty' instrument was used to collect three samples from the left testis of each stallion. The oestradiol, testosterone and inhibin content in each testis were assessed by validated radioimmunoassay (RIA); protein concentrations were determined and the testes were prepared histologically for haematoxylin and eosin staining. The fertility status of each stallion was assessed before and after testicular biopsy by semen evaluation, changes in total scrotal width, ...
Equine castration: review of anatomy, approaches, techniques and complications in normal, cryptorchid and monorchid horses. Complications associated with equine castration are the most common cause of malpractice claims against equine practitioners in North America. An understanding of the embryological development and surgical anatomy is essential to differentiate abnormal from normal structures and to minimise complications. Castration of the normal horse can be performed using sedation and regional anaesthesia while the horse is standing, or under general anaesthesia when it is recumbent. Castration of cryptorchid horses is best performed under general anaesthesia at a surgical facility. Techniques for castratio...
Glutathione-independent prostaglandin D2 synthase in ram and stallion epididymal fluids: origin and regulation. Microsequencing after two-dimensional electrophoresis revealed a major protein, glutathione-independent prostaglandin D2 synthase (PGDS) in the anterior epididymal region fluid of the ram and stallion. In this epididymal region, PGDS was a polymorphic compound with a molecular mass around 30 kDa and a range of pI from 4 to 7. PGDS represented 15% and 8% of the total luminal proteins present in this region in the ram and stallion, respectively. The secretion of the protein as judged by in vitro biosynthesis, and the presence of its mRNA as studied by Northern blot analysis, were limited to the ...
Neoplasia of the male reproductive tract. Genital neoplasms in the male horse are relatively uncommon. Squamous cell carcinomas and squamous papillomas are the most commonly diagnosed neoplasms of the penis and prepuce. Geldings appear to be overrepresented for these types of neoplasms, and accumulation of smegma may be a contributing factor. Early diagnosis and treatment are essential for salvaging these organs before lesions become excessively large and invasive or are allowed to metastasize. Newer treatment modalities such as 5-fluorouracil appear to be promising alternatives to surgical excision. Although generally considered to b...
Postcastration eventration in 18 horses: the prognostic indicators for long-term survival (1985-1995). Castration of horses is considered a common and routine surgical procedure, but the potential for complications is high. By far the most serious of these is eventration. The objectives of this study were to determine the long-term survival of horses undergoing surgical treatment of indirect (1) inguinal eventration of the small intestine following castration, and to identify prognostic indicators for survival. The case records of 18 horses undergoing surgical treatment of postcastration eventration (PCE) between 1985 and 1995 were reviewed. Follow-up information was obtained by telephone inter...
Viability of an inguinal testis after laparoscopic cauterization and transection of its blood supply. A 25-month-old castrated horse was admitted for evaluation of stallion-like behavior. Twelve months earlier, bilateral cryptorchidism had been diagnosed, and the horse underwent a laparoscopic castration. At that time, the left testis was removed from the abdominal cavity, but the right testis, which was located in the inguinal ring, was left in place to undergo avascular necrosis after laparoscopic cauterization and transection of the testicular vasculature. On physical examination, an apparently clinically normal right testis was palpated within the scrotum. Administration of human chorionic...
Neopterin values in selected groups of normal animals. To establish baseline information on neopterin concentrations in livestock, companion and laboratory animals and identify the factors that may influence these concentrations, blood samples were taken from normal dairy cattle, horses, llamas, dogs, cats and rats of varying ages and sexes. In addition, neopterin concentrations in normal, adult equines were compared with those found in racing Thoroughbreds. There were no differences due to sex, sexual maturity, pregnancy, castration, or age. For all ages and sexes combined, mean neopterin concentrations were significantly lower in llamas (2.27+/-...
Complications associated with administration of detomidine into the caudal epidural space in a horse. A 364-kg (800-lb) 15-month-old sexually intact cryptorchid male Quarter Horse was admitted to the veterinary teaching hospital for castration. The horse was placed in standing stocks, and a caudal epidural injection of 18 mg of detomidine hydrochloride (50 micrograms/kg [23 micrograms/lb] of body weight) was administered. Fifteen minutes after injection, the horse unexpectedly collapsed to the floor, first into sternal, and then into lateral, recumbency. Because the horse would not get up, the decision was made to perform the surgery with the horse under general anesthesia. The horse required ...
Cardiovascular effects of surgical castration during anaesthesia maintained with halothane or infusion of detomidine, ketamine and guaifenesin in ponies. Sixteen colts were premedicated with acepromazine and anaesthesia was induced with detomidine and ketamine. Ponies were randomly allocated to receive halothane (HAL) or infusion of detomidine, ketamine and guaiphenesin (DKG) to maintain anaesthesia. Heart and respiratory rate, ECG, mean arterial blood pressure (MABP), cardiac index (CI), blood gases and plasma cortisol, ketamine and guaiphenesin were measured. Surgical castration took place between 45 and 75 min and anaesthesia lasted 90 min. MABP with DKG was significantly higher than with HAL, and, with HAL, MABP increased from pre-surgery (...
[Experiences with spermatic cord ligation as a method of castration in the stallion. The surgical castration of the testicle in situ appears to be of value]. In 22 stallions the surgically prepared spermatic cord was crushed and ligated. Preoperative and postoperative plasma-testosterone concentrations were measured and 60 days after surgery a HCG-stimulation test was carried out in 12 horses. In these 12 horses the testosterone production had ceased. In all 22 horses the wounds healed by primary intention. Ligation of the spermatic cord is a castration technique without surgical complications, at least in this study.
Testicular inhibin in the stallion: cellular source and seasonal changes in its secretion. The cellular localization of inhibin alpha, betaA, and betaB subunits, 3beta-hydroxysteroid dehydrogenase (3beta-HSD), and cytochrome P450 aromatase (aromatase) in stallion testes was investigated. In addition, detailed seasonal changes in circulating immunoreactive (ir)-inhibin were investigated in correlation with testosterone, estradiol, LH, and FSH. Inhibin alpha subunit-positive staining was observed in Sertoli cells, and more clearly positive staining was noted in Leydig cells. Inhibin betaA and betaB subunits were also stained in both types of cells. Immunoreactivity of 3beta-HSD and ar...
Inhibin secretion in the stallion. To examine the physiological role of inhibin in the stallion, a heterologous radioimmunoassay (RIA) based on a bovine RIA was validated and used to measure immunoreactive (ir)-inhibin concentrations in plasma and testicular homogenates. The bioactivity of equine testicular inhibin was also examined using an assay for suppression of FSH secretion from rat anterior pituitary cells. In addition, to identify the cell responsible for secreting testicular inhibin, the localisation of inhibin in the testis was investigated by an immunohistochemical method using a polyclonal antibody against (Tyr30)-p...
Laparoscopic intra-abdominal ligation and removal of cryptorchid testes in horses. Laparoscopic intra-abdominal ligation and removal of cryptorchid testes in horses was evaluated retrospectively in 50 horses that underwent the procedure between 1991 and 1996. Sixty-one cryptorchid testes were removed by one of the following methods; the use of 1) an endoscoping stapling and transection device, 2) an endoscopic clipping device, 3) an endoscopic ligating loop. Monopolar electrosurgery was combined with these methods to facilitate coagulation and cutting of tissue. In 8 horses, 9 testes were retained between the internal and external inguinal rings. The inguinal testes were rem...
Effects of age, season, and fertility status on plasma and intratesticular immunoreactive (IR) inhibin concentrations in stallions. The nature of the relationship between inhibin and reproductive function in the stallion is yet to be elucidated. Blood and testes from 51 light horse stallions ranging in age from 2 mo to 25 years were collected during the breeding and nonbreeding seasons to study the effects of testicular maturation, aging, season, and fertility status on peripheral and intratesticular concentrations of Ir inhibin and other reproductive hormones. Of the 51 stallions, 12 age-matched stallions (6 fertile, 3 subfertile, and 3 infertile) were used in the fertility study. Blood samples were taken before castratio...
Ventral abdominal approach for laparoscopic cryptorchidectomy in horses. To report a ventral abdominal approach and a ligating loop technique for laparoscopic cryptorchidectomy in horses. Methods: Prospective. Methods: Six horses, aged 1 to 5 years, with retained testes. Methods: One laparoscopic portal and three to four instrument portals were used for ventral abdominal laparoscopic cryptorchidectomy. Laparoscopic instruments were used to maneuver and secure the testis through a ligating loop (modified Roeder knot) that was secured from outside the abdominal cavity. Only minimal enlargement of one instrument portal was used to remove the testicle. Results: Three h...
Immunocytochemical differences in adenohypophyseal cells among adult Mongolian pony mares, stallions, and geldings. To analyze the sex difference in 6 kinds of adenohypophyseal cells of Mongolian ponies and the effect of prepubertal orchidectomy on adenohypophyseal cells. Methods: Pituitary glands collected from 15 adult Mongolian ponies, 5 to 10 years old: 5 stallions, 5 mares, and 5 geldings, orchidectomized between the ages of 1 and 2 years. Methods: Morphologic comparison of 6 kinds of adenohypophyseal cells among mares, stallions, and geldings was done, using immunocytochemistry and morphometry. Results: A sex difference was evident in the percentage of somatotrophs, gonadotrophs (follicle-stimulating ...
Laparoscopic cryptorchid castration in standing horses. This article describes a new technique for laparoscopic cryptorchid castration in standing horses. Methods: Prospective study. Methods: Eight horses aged 11 months to 3 years and weighing between 300 and 643 kg. Methods: Food was withheld for 24 to 36 hours, and then horses were sedated with detomidine HCl (0.02 to 0.03 mg/kg) and butorphanol tartrate (0.02 mg/kg). The paralumbar fossa region was desensitized with 2% mepivacaine in an inverted "L" pattern and caudal epidural anesthesia was administered with either xylazine (0.18 mg/kg diluted to 10 to 15 mL with 0.9% sodium chloride) or a comb...
HCG binding to the testicular LH receptor is similar in fertile, subfertile, and infertile stallions. Recent evidence in our laboratory suggests that the cause of idiopathic subfertility/infertility in breeding stallions may originate in the testes at the luteinizing hormone (LH) receptor or postreceptor level. The objective of this research was to determine if LH receptor binding activity is altered in subfertile and infertile stallions. Six fertile, three subfertile, and three infertile stallions, ages 11-23 years, were classified according to normal semen parameters and pregnancy rates and then castrated in the breeding season. Blood was collected prior to castration, and plasma was stored ...
Laparoscopic cryptorchidectomy in standing horses. The purpose of this study was to determine the feasibility of using laparoscopy to remove cryptorchid testes from standing horses. Methods: Prospective clinical study. Methods: Eleven client-owned horses ranging in age from 4 months to 2 years. Methods: Abdominal insufflation was initiated and maintained using a 20 F insufflation tube, attached via a stopcock, to the low pressure regulator on a standard carbon dioxide pressure tank. After trocar and laparoscope placement in the ipsilateral flank the testes were identified. Local anesthesia of the structures to be manipulated was administered t...
A pharmacodynamic study of propofol or propofol and ketamine infusions in ponies undergoing surgery. The pharmacodynamics of infusions of propofol alone (group 1) were compared with the pharmacodynamics of infusions of propofol and ketamine together (group 2) in eight ponies undergoing castration. Anaesthesia was induced with detomidine, 20 micrograms kg-1, followed by ketamine, 2.2 mg kg-1. Subsequently, a bolus dose of propofol, 0.5 mg kg-1, was administered intravenously to both groups, and an infusion of propofol was given for an average of 74 minutes to group 1, and an infusion of propofol and ketamine was given for 60 minutes to group 2. The mean (SD) infusion rates of propofol were 0.3...
Laparoscopic methods for castration of equids. To evaluate 2 laparoscopic techniques for castration of horses. Methods: Prospective, randomized trial. Methods: 6 sexually intact male ponies. Methods: Ponies were anesthetized and placed in dorsal recumbency. By means of restricted randomization, 1 testis in each pony was selected to undergo in situ destruction (i.e., vascular cauterization and ligation with the testis left in situ); the other testis was pulled back into the abdomen and removed. Baseline and stimulated testosterone concentrations were determined preoperatively and postoperatively. After euthanasia, the in situ testes were ex...
XX male pseudohermaphroditism in a horse. A pseudohermaphrodite horse with aggressive stallion-like behavior and ambiguous external genitalia was gonadectomized. The hypoplastic gonads removed from the abdomen were confirmed by histologic examination to be testes. Examination of blood and fibroblasts revealed a 64,XX karyotype.
Reproductive emergencies in the stallion. Topics addressed in this article include complications of castration, scrotal and inguinal hernias, torsion of the spermatic cord, traumatic injuries to the external genitalia, and posthumous collection of spermatozoa. A concise overview of the clinical management of emergency cases is provided.