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.
Castration in the standing horse combining laparoscopic and conventional techniques. Standing laparoscopic castration without orchidectomy has been shown to be a reliable method of castration in animals with abdominal cryptorchidism, but it cannot be recommended as a method of castration in those with inguinal cryptorchidism or normal males. An alternative laparoscopic method for the castration of horses with descended testes was developed. Objective: To report the results of laparoscopy-assisted abdominal transection of the spermatic cord and a modified open method in the standing horse for castration of descended testes in unilateral abdominal cryptorchids. Methods: Descript...
Alfaxalone for maintenance of anaesthesia in ponies undergoing field castration: continuous infusion compared with intravenous boluses. To compare alfaxalone as continuous intravenous (IV) infusion with intermittent IV injections for maintenance of anaesthesia in ponies undergoing castration. Methods: Prospective, randomized, 'blinded' clinical study. Methods: A group of 33 entire male Welsh ponies undergoing field castration. Methods: After preanaesthetic medication with IV detomidine (10 μg kg) and butorphanol (0.05 mg kg), anaesthesia was induced with IV diazepam (0.05 mg kg) followed by alfaxalone (1 mg kg). After random allocation, anaesthesia was maintained with either IV alfaxalone 2 mg kg hour (group A; n ...
Laparoscopic cryptorchidectomy with a vessel-sealing device in dorsal recumbent horses: 43 cases. To document laparoscopic cryptorchidectomy with a vessel-sealing device in dorsal recumbent horses. Methods: Retrospective study. Methods: Forty-three male horses. Methods: Food was withheld for 36 hours before horses were placed under general anesthesia and positioned in dorsal recumbency. One laparoscopic portal and 2 instrument portals were placed for the laparoscopic procedure. A third instrument portal was created in bilateral cryptorchid horses. A vessel-sealing device was used for hemostasis and transection of retained testes. Descended testes were removed via closed castration with pri...
Oxidative stress markers in Thoroughbred horses after castration surgery under inhalation anesthesia. Oxidative stress has been reported to occur during surgery. It is important to reduce intraoperative oxidative stress to improve the postoperative prognosis. However, there are no reports regarding oxidative stress related to surgery in horses. In the present study, we measured pre and postsurgical diacron-reactive oxygen metabolites (d-ROMs) and biological antioxidant potential (BAP); the oxidative stress index (OSI) was then calculated (OSI=d-ROMs/BAP × 100). d-ROMs were not significantly different between the pre and postsurgical periods. However, BAP significantly decreased after surgery ...
Evaluation of chemical castration with calcium chloride versus surgical castration in donkeys: testosterone as an endpoint marker. For the last few years, researchers have been interested in developing a method for chemical sterilization which may be a better alternative to surgical castration. An ideal chemical sterilant would be one that effectively arrests spermatogenesis and androgenesis as well as libido with absence of toxic or other side effects. Calcium chloride in various solutions and concentrations has been tested in many animal species, but few studies have been evaluated it in equines as a chemical sterilant. So, the objective of this study was to evaluate the clinical efficacy of chemical castration with 20%...
Ex vivo comparison of the giant and transfixing knot in equine open and closed castration. In equine castration, application of a ligature on the spermatic cord to prevent complications such as haemorrhage and evisceration has been reported with controversial results. Characteristics of commonly used knots have not been studied. Objective: To compare the modified transfixing and giant knots and the emasculator in open and closed equine castration techniques. Methods: Ex vivo experiment. Methods: A total of 144 testicles were randomly assigned to 2 groups for open or closed castration. Both groups were divided into 3 subgroups of 18 specimens each: emasculator only, emasculator plus ...
Comparison of Chemical and Surgical Vasectomy on Testicular Activity in Free-Roaming Horses (Equus caballus) Free-roaming horse (Equus caballus) management is a complex issue incorporating social, economic, emotional, political, and environmental factors. Currently, few proven field techniques exist for managing free-roaming horse population growth, which can reach 20-25% annually. Although there are several strategies available for sterilizing mares when managing free-roaming horse populations, surgical vasectomy is the only method used in the field for stallions. Some managers believe that surgically vasectomizing dominant stallions would have significant effects on reducing horse populations. Howe...
Anatomical variations in epididymal-testicular fusion in stallions and their possible clinical significance. Fusion anomalies of the epididymis with the testis may be clinically relevant in horses. However, anatomical variations in epididymal-testicular fusion have not been classified, and their clinical significance is unknown. Objective: To describe anatomical variations and clinical significance of epididymal-testicular fusion in stallions. Methods: Anatomical study of testes from castrations, and description of 2 clinical cases with atypical epididymal-testicular fusion. Methods: A total of 104 testes were obtained from equine castrations. Eight patterns of epididymal-testicular fusion were ident...
Sperm DNA quality evaluated by comet assay and sperm chromatin structure assay in stallions after unilateral orchiectomy. Unilateral orchiectomy (UO) may interfere with thermoregulation of the remaining testis caused by inflammation surrounding the incision site, thus altering normal spermatogenesis and consequently sperm quality. Two measures of sperm DNA quality (neutral comet assay and the sperm chromatin structure assay [SCSA]) were compared before UO (0 days) and at 14, 30, and 60 days after UO to determine whether sperm DNA changed after a mild testis stress (i.e., UO). The percent DNA in the comet tail was higher at 14 and 60 days compared to 0 days (P < 0.05) after UO. All other comet tail measures (i....
Characterization of the equine blood-testis barrier during tubular development in normal and cryptorchid stallions. The formation of the blood-testis barrier (BTB) is defined as occurring with the first appearance of spermatocytes at around puberty and is vital for normal spermatogenesis. This barrier between two adjacent Sertoli cells (SCs) consists of a cell junctional protein complex, which includes tight junctions (TJs), adherens junctions, and gap junctions. In many mammalian species, BTB composition has already been investigated, whereas little is known about the equine BTB. In the present study, immunohistochemistry and qualitative Western Blot analysis were used to assess the expression and distribu...
Clinical and pharmacokinetic evaluation of S-ketamine for intravenous general anaesthesia in horses undergoing field castration. Intravenous anaesthetic drugs are the primary means for producing general anaesthesia in equine practice. The ideal drug for intravenous anaesthesia has high reliability and pharmacokinetic properties indicating short elimination and lack of accumulation when administered for prolonged periods. Induction of general anaesthesia with racemic ketamine preceded by profound sedation has already an established place in the equine field anaesthesia. Due to potential advantages over racemic ketamine, S-ketamine has been employed in horses to induce general anaesthesia, but its optimal dose remains und...
Effects of an anabolic steroid (Durateston) on testicular angiogenesis in peripubertal stallions. The aim of this study was to determine the effect of the anabolic steroid testosterone on the testicular vascularization, angiogenesis and expression of angiogenic factors, and their receptors in testes of peripubertal stallions. Seven peripubertal stallions were treated with Durateston and castrated either 4 (treatment group 1 [TG1]) or 12 weeks (TG2) after the last injection. The castration of seven untreated control stallions (control group [CG]) took place within the same time. In the testicular specimens, volume density (VD), numerical density (ND), and area of vessels were determined mor...
Anti-Müllerian hormone as an indicator of hemi-castrated unilateral cryptorchid horses. Anti-Müllerian hormone (AMH), a glycoprotein secreted from the fetal testis, is responsible for regression of the Müllerian duct in the male fetus. The aim of this study was to evaluate the usefulness of serum AMH as a biomarker for diagnosis of cryptorchidism in horses. Serum AMH concentrations were measured in intact stallions, hemi-castrated unilateral cryptorchid stallions, and geldings. In addition, expression of AMH was characterized in cryptorchid testes by immunohistochemistry. Serum AMH was detected in intact stallions (n=11, 13.3 ± 1.8 ng/ml) and in hemi-castrated cryptorchid stal...
Cryptorchidectomy in equids: 604 cases (1977-2010). To evaluate the management of equids undergoing cryptorchidectomy at a referral hospital. Methods: Retrospective case series. Methods: 604 client-owned equids. Methods: Medical records of all equids undergoing surgical treatment of cryptorchidism from 1977 to 2010 were retrospectively reviewed. Analyses of breed, location of retained testes, accuracy of palpation per rectum for determining the location of retained testes, surgical technique, and postoperative complications were performed. Results: The most frequently affected breed was the Quarter Horse (282/604 [47%]), which was significantly...
Dexamethasone acutely regulates endocrine parameters in stallions and subsequently affects gene expression in testicular germ cells. Testicular steroidogenesis and spermatogenesis are negatively impacted by stress-related hormones such as glucocorticoids. The effects of two injections of a therapeutic dose of dexamethasone (a synthetic glucocorticoid, 0.1mg/kg; i.v.) given 24h apart to each of three stallions were investigated and compared to three saline-injected control stallions. Dexamethasone decreased circulating concentrations of cortisol by 50% at 24h after the initial injection. Serum testosterone decreased by a maximum of 94% from 4 to 20h after the initial injection of dexamethasone. Semen parameters of the dexame...
Comparison of midazolam and diazepam as co-induction agents with ketamine for anaesthesia in sedated ponies undergoing field castration. To compare intravenous (IV) midazolam and diazepam administered with ketamine for induction of anaesthesia in ponies, already sedated with detomidine, undergoing field castration. Methods: Prospective, randomised, 'blinded', clinical study. Methods: Twenty Welsh pony yearlings. Methods: After IV injection of detomidine (20 μg kg(-1) ) and phenylbutazone (4.4 mg kg(-1) ) ponies were allocated to receive either IV midazolam (group M) or diazepam (group D) (both 0.06 mg kg(-1) ) with ketamine (2.2 mg kg(-1) ) for induction of anaesthesia. Using simple descriptive scales, quality of sedat...
Buprenorphine provides better anaesthetic conditions than butorphanol for field castration in ponies: results of a randomised clinical trial. A prospective, randomised, blinded, clinical trial in 47 ponies compared butorphanol and buprenorphine administered intravenously with detomidine prior to castration under anaesthesia. Detomidine 12 μg/kg intravenously was followed by butorphanol 25 μg/kg (BUT) or buprenorphine 5 μg/kg (BUP) before induction of anaesthesia with intravenous ketamine and diazepam. Quality of sedation, induction and recovery from anaesthesia, response to tactile stimulation, and surgical conditions were scored. If anaesthesia was inadequate 'rescue' was given with intravenous ketamine (maximum three dose...
Dexamethasone acutely down-regulates genes involved in steroidogenesis in stallion testes. In rodents, livestock and primate species, a single dose of the synthetic glucocorticoid dexamethasone acutely lowers testosterone biosynthesis. To determine the mechanism of decreased testosterone biosynthesis, stallions were treated with 0.1mg/kg dexamethasone 12h prior to castration. Dexamethasone decreased serum concentrations of testosterone by 60% compared to saline-treated control stallions. Transcriptome analyses (microarrays, northern blots and quantitative PCR) of testes discovered that dexamethasone treatment decreased concentrations of glucocorticoid receptor alpha (NR3C1), alpha a...
Control of the misuse of testosterone in castrated horses based on an international threshold in plasma. Testosterone is an endogenous steroid produced primarily in the testes. Trace levels of testosterone are found in urine samples from geldings, as testosterone is also secreted by the adrenal. An international threshold of free and conjugated testosterone in urine (20 ng/mL) was adopted by the International Federation of Horseracing Authorities (IFHA) in 1996 for controlling testosterone misuse in geldings. In view of the recent popularity of using blood in doping control testing, it is necessary to establish a threshold for testosterone in gelding plasma. A liquid chromatography-mass spectro...
Surgical stress influences cytokine content in autologous conditioned serum. No recommendations have been made regarding the relative timing of blood collection for autologous conditioned serum (ACS) preparation and surgical procedures. Objective: 1) To identify effects of surgical stress on cytokine levels in ACS, 2) identify haematological markers for prediction of cytokine production in ACS and 3) investigate the necessity for specialised ACS containers when preparing a cytokine-rich serum. Methods: Experimental in vitro study. Methods: Blood was drawn from 15 stallions admitted for elective castration preoperatively and 22-24 h post operatively and incubated in A...
Use of a motorized morcellator for elective bilateral laparoscopic ovariectomy in standing equids: 30 cases (2007-2013). To describe the use of a motorized morcellator for elective bilateral laparoscopic ovariectomy in standing equids and to evaluate long-term outcome. Methods: Retrospective case series. Methods: 30 equids (20 horses, 9 mules, and 1 pony). Methods: Medical records of equids undergoing elective bilateral laparoscopic ovariectomy from 2007 to 2013 were evaluated. Cases were selected on the basis of use of a motorized morcellator for ovary extraction. Data collected included age, breed, reason for surgery, surgery date, surgical approach, intraoperative complications, surgery and morcellation times...
Surgical treatment of 4 horses for cryptorchidism caused by failure of regression of the cranial suspensory ligament of the testis. To report surgical management of 4 horses with cryptorchidism caused by failure of regression of the cranial suspensory ligament (CSL). Methods: Retrospective case series. Methods: Cryptorchid horses (n = 4). Methods: Horses with unilateral or bilateral cryptorchidism caused by failure of regression of the CSL were treated by removing the retained testes through a standing laparoscopic approach (2), flank laparotomy (1), or paramedian celiotomy (1). After identification of the retained testis attached to the caudal pole of the kidney by the CSL, the vascular pedicle and ductus deferens were li...
Spontaneous electroencephalographic changes in a castration model as an indicator of nociception: a comparison between donkeys and ponies. Donkeys are believed to be less demonstrative of pain than ponies. Research into comparative sensory processing between these species is required to elucidate these behavioural differences. Objective: To compare changes in the electroencephalogram (EEG) recorded during castration between donkeys and ponies. Methods: Prospective clinical study. Methods: Six ponies and 6 donkeys were castrated under halothane anaesthesia after acepromazine premedication and thiopental anaesthetic induction. Markers were inserted into the EEG recording at the time of skin incision (skin) and emasculation (emasc) ...
Development of the Horse Grimace Scale (HGS) as a pain assessment tool in horses undergoing routine castration. The assessment of pain is critical for the welfare of horses, in particular when pain is induced by common management procedures such as castration. Existing pain assessment methods have several limitations, which reduce the applicability in everyday life. Assessment of facial expression changes, as a novel means of pain scoring, may offer numerous advantages and overcome some of these limitations. The objective of this study was to develop and validate a standardised pain scale based on facial expressions in horses (Horse Grimace Scale [HGS]). Results: Forty stallions were assigned to one of ...
Acute and chronic effects of a contraceptive compound RTI-4587-073(l) on testicular histology and endocrine function in miniature horse stallions. The objective of this study was to evaluate acute endocrine effects as well as histological changes in testicular parenchyma induced by the contraceptive compound RTI-4587-073(l). Six miniature stallions were used in this experiment. The treatment group (n = 3) received one oral dose of 12.5 mg/kg of RTI-4587-073(l), and the control group (n = 3) received placebo only. The stallions' baseline parameters (semen, testicular dimensions, endocrine values) were collected and recorded for 5 weeks before treatment and for 6 weeks after treatment. Multiple blood samples were collected for endoc...
Standing male equine urogenital surgery. The advantages of performing standing male urogenital surgeries are numerous when compared with performing the same surgery in the anesthetized animal. Some traditional standing male urogenital surgeries, such as castrations, may be faster and cheaper to perform. Laparoscopic standing male urogenital surgeries may allow for improved visualization of the surgical field, decreased hemorrhage, and decreased morbidity and convalescence. Limitations of standing procedures may include increased danger to the surgeon because of fractious behavior of the patient, and increased expense and training ass...
Postcastration analgesia in ponies using buprenorphine hydrochloride. Buprenorphine has recently obtained UK Marketing Authorisation for horses. The analgesic effects are long lasting, and have considerable potential for postoperative pain relief. This observer blinded, randomised study aimed to evaluate postsurgical analgesia in ponies premedicated with buprenorphine prior to castration under intravenous anaesthesia. Ponies received either 0.01 mg/kg bodyweight (BW) buprenorphine (group B) or an equivalent volume of 5 per cent glucose (group C) given intravenously before induction of anaesthesia. Pain was assessed and recorded using dynamic interactive visual a...
Equine laparoscopy: gonadectomy. Laparoscopic removal of the gonads from male and female horses is regularly performed for a variety of reasons. In female horses, common indications for ovariectomy include behavioral problems and signs of abdominal pain that are linked to estrus. Another indication is an abnormal, enlarged ovary, typically due to ovarian neoplasia, the most common being granulosa thecal cell tumor. Ovariectomy is also a treatment option for ovarian hematomas and other abnormalities. In addition, ovariectomy is used to sterilize mares intended for artificial insemination or embryo transfer programs.
Effect of surgical technique for unilateral orchiectomy on subsequent testicular function in Miniature Horse stallions. Management decisions on unilateral orchiectomy are often influenced by the potential for post operative return to successful breeding. The effects of 2 surgical methods (first intention [FI] vs. second intention [SI] incision healing) for unilateral orchiectomy on resulting semen quality and scrotal temperature were evaluated. Objective: To evaluate the effects of 2 surgical unilateral orchiectomy techniques on scrotal healing, size of the remaining testis and post operative sperm quality. Methods: Unilateral orchiectomy was performed on mature Miniature Horse stallions. Semen was collected pr...