Evaluation of ‘Section‐Ligation‐Release (SLR)’ Technique Devised for Castration in the Stallion

A novel technique [Section‐Ligation‐Release (SLR)] was evaluated for castration in the horse. Clinical traits, serum testosterone concentrations after challenge with human chorionic gonadotrophin (hCG), and histopathological changes of the testicular tissue were assessed. Five stallions, aged 24–48 months, were castrated using SLR technique under general anaesthesia. Both spermatic cords in each stallion were exposed at the scrotal neck by two 5‐cm long incisions, followed by sharp dissection through the parietal vaginal tunic. Both vascular and non‐vascular structures in the cords were triple clamped, transected and ligated. Both testes were left in situ. Serum testosterone concentrations were measured pre‐operatively and at 2 months after castration following IV administration of 1 × 10⁴ IU of hCG. Both testes from each castrate were collected at 2 months for histopathologic examination. SLR castration was successfully achieved. Moderated scrotal and preputial swelling was the only experienced short‐term complication. Serum testosterone concentrations were significantly lower than basal pre‐operative levels at 2 months after castration, and did not respond to hCG. On histopathology, hyalinization of the seminiferous tubules and loss of testicular interstitial tissue were indicative of complete avascular necrosis. This novel primary closure castration technique of stallion is a simple practical method, with minimal post‐operative complications; and could be safely advocated as an alternative to the traditional castration techniques allowing for second intention healing of scrotal wounds.     

Normal and cryptorchid castration

Surgical exploration of the horse that has presumably had a normal castration or a previously successful cryptorchid surgery remains a distinct challenge. No hard and fast rules dictate a proper course of action for each case. If a horse was anesthetized for routine castration, discovered to have only one scrotal testis, had a brief exploratory on the nondescended side and was recovered, trauma to the inguinal region would probably be sufficiently minimal that an inguinal approach could be used at subsequent exploratory surgery. If the inguinal canal was extensively manipulated and the tail of the epididymis was inadvertently removed, however, one of the alternate approaches would be advisable. Where previous history is unknown, external and rectal palpation, hormonal assays, and careful evaluation of the scrotal/inguinal scars under anesthesia are advisable prior to proceeding with a specific course of action. As previously cited, "one hopes for the best but prepares for the worst." Where inguinal canals are being explored in the supposedly previously castrated horse that still has aggressive male behavior, the surgeon is searching for vaginal process and contents or the stump of the spermatic cord. If the stump is identified to suggest complete previous castration, the stump should contain cremaster muscle, parietal vaginal tunic, testicular vessels, and ductus deferens. If a second nonvascular tubular structure is found but no testicular vessels are found, the tail of the epididymis was inadvertently removed and assumed to be hypoplastic testis. This determination can be difficult to make on gross observation of the stump. Again, a thorough case workup helps one plan in advance for what should be found at surgery.     

Acquired incarcerated inguinal hernia: a review of 13 horses

The case records of 13 horses with acquired incarcerated inguinal hernia in January-August 1983, were reviewed. Nine cases were in stallions. The remaining four involved eventration 5-48 hours following castration. Ages ranged from 1-17 years. Horses showed a variable degree of colic. Bowel was felt to pass through the internal inguinal ring on rectal examination in most cases. The physical features of the scrotum varied considerably. Resection of ischemic jejunum and/or ileum was necessary in three horses. Two horses were euthanized at surgery (one with bilateral ischemic jejunum, one with bowel perforation), and a further horse on day 16 postsurgery following development of multiple adhesions. All stallions were castrated. Follow-up for 6-24 months (mean 12.7) disclosed that all ten discharged horses were alive and healthy (recovery rate 77%).     

Surgical thrombectomy in horses with aortoiliac thrombosis: 17 cases

Reasons for performing study: Aortoiliac thrombosis (AIT) is a progressive vascular disease characterised by an exercise‐induced hindlimb lameness. After developing a surgical technique, a follow‐up study was required. Objectives: To assess the surgical results of a surgical thrombectomy in horses with AIT, a chronic arterial occlusive disease of the aorta and its caudal arteries. Methods: Seventeen cases showed the typical signs of AIT and diagnosis was confirmed by Doppler‐ultrasonography. Average age of the horses was 12 years. Seven stallions, 6 mares and 4 geldings were included. Results: The thrombus was located in the left hindlimb (5 cases), the right hindlimb (9 cases) or in both hindlimbs (3 cases). Two cases were operated on both limbs with a few days between surgeries. Nine (53%) horses regained their athletic performance and 2 horses were able to work for at least 30 min without complaint, instead of the initial 5 min prior to surgery. During surgery one horse had to be subjected to euthanasia because the thrombus was too tightly attached to the arterial wall and could not be removed. Two horses were subjected to euthanasia post operatively due to severe myopathy and one due to a femoral fracture during recovery. Two reocclusions of the treated artery occurred 4 months after surgical intervention: one horse was reoperated and, due to the extent of the thrombus and quality of the arterial wall, the horse was subjected to euthanasia; the other horse was subjected to euthanasia without a second surgery. A severe complication was the appearance of AIT in the contralateral limb after surgery as result of occlusion caused by an embolus loosened by the procedure. Post anaesthetic myopathy was seen in 4 (24%) of the cases and could be so severe that euthanasia had to be considered. Conclusion and potential relevance: Surgical intervention by means of a thrombectomy in horses with AIT should be considered; 65% of the horses regained athletic activity and 53% of the operated horses in this study performed at their previous level. Adequate padding, correct positioning, prevention of intraoperative hypotension and keeping surgery time as short as possible, are important parameters to prevent post operative myopathy.     

Surgical treatment of acquired inguinal hernia in the horse: a review of 51 cases

During a seven year period, 51 cases of acquired inguinal herniation in 50 stallions were treated surgically. In 25 cases the herniated loop was ileal, in the other 26 it was jejunal. In cases of strangulation, the vaginal ring was enlarged by incising the peritoneum and transverse fascia. Closure of the superficial inguinal ring was advisable to prevent the hernia recurring. In all cases unilateral castration was performed. Laparotomy was carried out in 33 cases; 22 required intestinal resection and in four cases a bypass was made. Follow-up at least six months postoperatively indicated that surgery had been successful in 76 per cent of the cases treated.     

Analgesic effect of butorphanol in ponies following castration

Reasons for performing study: In the UK butorphanol has a marketing authorisation for administration to horses for sedation in combination with detomidine, and at a higher dose (0.1 mg/kg bwt), for the alleviation of pain. There is only a limited number of clinical studies designed to examine the analgesic effects of butorphanol administration following surgery. Objective: To investigate the effect of premedication with butorphanol on post operative pain following castration under general anaesthesia in ponies. Hypothesis: Ponies receiving butorphanol would experience less pain after castration than ponies that did not receive butorphanol. Methods: A randomised, observer blinded clinical study in which 20 ponies received butorphanol and detomidine (Group B) or detomidine alone (Group C). Anaesthesia was induced with ketamine and diazepam and open castration performed. Pain was assessed by one individual using a dynamic interactive visual analogue scale (DIVAS) 100 mm in length (0 = no pain, 100 mm the maximum possible pain for that procedure). ‘Rescue’ analgesia was administered when DIVAS >50 mm and was butorphanol i.v. On the second occasion DIVAS was >50 mm, flunixin was administered i.v. Data from the DIVAS were analysed using a Mann Whitney Test. Results: Only one animal did not require rescue analgesia after surgery (Group C). DIVAS were not significantly different between groups (P = 0.063). Conclusions and potential relevance: Castration is sufficiently painful that administration of a single preoperative dose of butorphanol does not provide adequate post operative analgesia.     

Castration of the Vietnamese pot-bellied boar: 8 cases

Surgical techniques for castration of the Vietnamese pot-bellied boar and outcome are described. Vietnamese pot-bellied pig (VPBP) boars (n = 8) were admitted for castration. Data retrieved from medical records (2002–2011) for these pigs included signalment, history, reason for castration, perioperative management, surgical technique, and complications. Follow-up information was obtained from owners. A scrotal approach with closed technique was used for 6 boars with normally descended testes. A scrotal approach and open technique was used in 1 inguinal cryptorchid boar. In a hemicastrated abdominal cryptorchid boar an ipsilateral parainguinal approach was used. No complications occurred. Castration of the Vietnamese pot-bellied boar is associated with minimal complications and a satisfactory cosmetic outcome. We recommend the routine closure of the external inguinal rings, a simple and fast procedure that may prevent post-castration inguinal herniation.     

Survival of horses following strangulating large colon volvulus

Reasons for performing study: The pattern of long‐term survival and specific factors associated with long‐term survival have not previously been evaluated in horses with a strangulating large colon volvulus (LCV). Objectives: To provide data on the long‐term survival of horses with LCV and to identify pre‐, intra‐ and post operative variables associated with survival. Methods: Clinical data and long‐term follow‐up information were obtained from 116 horses with a strangulating LCV (≥360°) undergoing general anaesthesia. Two multivariable Cox proportional hazards models for post operative survival time were developed: Model 1 included all horses and evaluated preoperative variables and Model 2 included horses that survived anaesthesia and evaluated pre‐, intra‐ and post operative variables. Results: The study population comprised 116 horses. Eighty‐nine (76.7%) survived general anaesthesia. Of these, the percentage that survived until discharge, to one year and to 2 years was 70.7%, 48.3% and 33.7%, respectively. Median survival time for horses that survived general anaesthesia was 365 days. In Model 1 increased preoperative packed cell volume (PCV) was significantly associated with reduced post operative survival (hazard ratio [HR] 1.08, 95% confidence interval [CI] 1.05–1.11). However, this effect changed over time. In Model 2 abnormal serosal colour intraoperatively (HR 3.61, 95% CI 1.55–8.44), increased heart rate at 48 h post surgery (HR 1.04, 95% CI 1.02–1.06), and colic during post operative hospitalisation (HR 2.63, 95% CI 1.00–6.95), were all significantly associated with reduced post operative survival. Conclusions: Survival time in horses with a LCV was associated with preoperative PCV, serosal colour, heart rate at 48 h post operatively and colic during post operative hospitalisation. Potential relevance: This study provides evidence‐based information on the long‐term survival of horses with LCV and identifies parameters that may assist decision‐making by clinicians and owners.     

Midline scrotal ablation technique for unilateral cryptorchid castration in horses

Thirty-nine unilateral cryptorchid horses were castrated, using a midline scrotal ablation technique. This approach was satisfactory to access both inguinal rings, to eliminate the need for 2 incisions, and to allow for completion of the surgery by primary closure. These horses recovered from surgery with few complications, returned to work promptly, and had excellent cosmetic results.     

Comparison of the diagnosis and management of unilaterally castrated and cryptorchid horses at a referral hospital: 60 cases (2002-2006)

OBJECTIVE: To determine the incidence of unilaterally castrated horses among horses admitted to the hospital for castration and to compare horses that underwent previous unilateral castration with horses that had cryptorchism. DESIGN: Retrospective case series. ANIMALS: 16 unilaterally castrated horses and 44 cryptorchid horses. PROCEDURES: Medical records of horses that were admitted to the veterinary medical teaching hospital for castration, including cryptorchid and unilaterally castrated horses, between January 2002 and December 2006 were reviewed. Medical records of unilaterally castrated horses and cryptorchid horses were examined for age, breed, history, diagnostic procedures, surgical technique of cryptorchidectomy, location of the retained testicle, and cost of surgery. RESULTS: Of 160 horses admitted for castration, 16 (10%) had undergone previous unilateral castration and 44 (27.5%) had cryptorchidism. Unilaterally castrated horses were significantly older than cryptorchid horses. No significant difference was found in left versus right distribution of testicles. No significant difference was found in abdominal versus inguinal distribution of left-sided testicles. Unilaterally castrated horses had a significantly lower proportion of right inguinal testicles, compared with cryptorchid horses. The cost of diagnosis and management of unilaterally castrated horses was significantly greater than in cryptorchid horses. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that the distribution of retained testicles is significantly different in unilaterally castrated horses, compared with cryptorchid horses, which may affect the selection of diagnostic and surgical approaches to unilaterally castrated horses.     

Evaluation of success rate of laparoscopic castration without orchidectomy in 32 mature horses

The surgical success of laparoscopic castration without orchidectomy results from avascular necrosis of the testes. However, failures and subsequent production of testosterone and stallion‐like behaviour have been previously identified. Laparoscopic castration without removal of the testes was performed in 32 horses with 2 normal descended scrotal testes between July 2006 and October 2012. The objectives of our study were to evaluate the success rate of laparoscopic castration without orchidectomy on descended testes in our population and assess complications and recovery time. Endocrine tests were performed after surgery and owners also asked to report on their horse's behaviour and ability to resume exercise. Castration was deemed successful if endocrine test results were in accordance with gelding values. Failed horses were castrated using a conventional technique and histology performed when possible. Basal testosterone levels decreased below 3 nmol/l after surgery in 30/32 cases. However, in 2 horses, stallion behaviour persisted and histological evaluation after inguinal castration showed residual viable tissue. Two horses maintained high testosterone levels after surgery associated with stallion‐like behaviour. Based on these results, 12.5% of horses (4/32 horses) failed to be considered a gelding based on either endocrine tests and/or histology. All horses, with one exception, were able to resume exercise less than a week after the procedure. Laparoscopic castration without orchidectomy appears to be a safe procedure. When assessing the success of laparoscopic castration, our total failure rate was 12.5% (4/32 horses) which is significantly higher than previously reported.     

The complex blood supply to the equine testis as a cause of failure in laparoscopic castration

REASONS FOR PERFORMING STUDY: Intra-abdominal ligation/ transection of the spermatic cord may result in necrosis of the testis; castration of abdominal cryptorchids via laparoscopy has therefore become common. Notwithstanding some adaptations of the technique, a small percentage of operations fail, prompting research into the anatomical background and clinical relevance of the procedure. HYPOTHESIS: That an alternate blood supply may prevent complete necrosis of the testis after spermatic cord transection. OBJECTIVE: To establish the prevalence of the problem in normal and cryptorchid stallions. METHODS: In a preliminary study, the spermatic cords of 8 normal stallions were ligated and transected at different sites and in various manners. Five weeks later the testes were removed and the vitality of both the testes and epididymes was evaluated. In a prospective clinical trial, intra-abdominal spermatic cord transection was performed in 241 cryptorchid and normal stallions. In cases of surgical failure, the testes were removed and histology performed. RESULTS: Examination of the specimen removed from the 8 animals of the preliminary study revealed that all epididymes were completely or largely spared. All except one testis were completely necrotic. In the patients that underwent surgery all abdominally retained testes (n = 123) were necrotic, while 5 out of 88 inguinally retained and 8 out of 236 normally descended testes had partially survived. The pattern of survival differed between inguinally retained and normally descended testes. The epididymes of these 13 horses were (largely) vital. The (partial) survival of the epididymes and inguinally retained testes was ascribed to an alternate blood supply via anastomosing vessels derived from the cremasteric artery. A tributary from the external pudendal artery was considered responsible for the partial survival of normally descended testes. CONCLUSIONS AND POTENTIAL RELEVANCE: After intra-abdominal transection of the entire spermatic cord, 5.6% of inguinally retained and 3.4% of normally descended testes failed to become completely necrotic, as a result of an alternate blood supply via the cremasteric and/or external pudendal artery. Therefore, laparoscopic castration without orchidectomy cannot be recommended as a trustworthy method for castration of inguinal cryptorchids and normal stallions.     

Use of serum amyloid A and other acute phase reactants to monitor the inflammatory response after castration in horses: a field study

REASONS FOR PERFORMING THE STUDY: Early recognition of excessive inflammation and infectious complications after surgery, leading to early institution of therapy, reduces post operative discomfort and facilitates recovery. Because serum amyloid A (SAA) is a highly sensitive marker of inflammation, measurements of SAA and other acute phase reactants in the equine surgical patient may be valuable in assisting clinical assessment of post operative inflammation. OBJECTIVES: To investigate changes in inflammatory markers after castration and to correlate levels of acute phase reactants with clinical severity of inflammation after castration. METHODS: Leucocyte numbers and blood levels of iron, SAA and fibrinogen were determined before castration and on Days 3 and 8 post operatively in 2 groups of horses; Group 1 (n = 11) had mild post operative inflammation and an uncomplicated recovery and Group 2 (n = 7) had local clinical signs of moderate to severe inflammation. RESULTS: Both groups had elevated serum SAA levels at Day 3 post operatively. In Group 1 concentrations had returned to preoperative levels by Day 8, whereas in Group 2 concentrations remained elevated. Plasma fibrinogen concentrations in serum increased to equal levels in both groups and stayed elevated throughout the study period. Serum iron concentrations of Group 1 did not change in response to castration, whereas concentrations in Group 2 decreased below preoperative levels on Day 8. Leucocyte numbers remained unchanged during the post operative period in both groups. CONCLUSIONS: Serum SAA and iron profiles reflected the course of inflammation and their levels correlated with the clinical severity of inflammation. In contrast, fever and changes in leucocyte numbers, which are usually considered to be hallmarks of inflammation and infection, were not useful for monitoring post operative recovery. POTENTIAL RELEVANCE: Measurements of SAA and iron may improve post operative monitoring. As sustained inflammation may indicate that the surgical wound has become infected, SAA and iron measurements may facilitate early recognition and hence early treatment of infection.     

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 laparoscopic approach was used. The horse recovered without further complications. Laparoscopy should be considered for ligation of the testicular artery in horses with uncontrolled bleeding after castration.     

Inguinal-Scrotal Urinary Bladder Hernia in an Intact Male Domestic Rabbit (Oryctolagus cuniculus)

An 8-year-old intact male dwarf rabbit (Oryctolagus cuniculus) was presented with a 2-month history of unilateral scrotal swelling. The external physical examination of the rabbit patient confirmed the severe, unilateral, fluid-filled scrotal distention. Radiographic images of the effected scrotum revealed a soft tissue swelling in the area of the left testicle, and the absence of the urinary bladder in the caudal abdomen. Ultrasonography verified the presence of a fluid-filled mass in the scrotum, enveloping the left testicle. A fine-needle aspiration of the scrotal mass yielded urine, thus a diagnosis of a nonreducible herniation of the urinary bladder into the scrotum was made. An inguinal herniorrhaphy was performed, and the bladder was successfully reduced into the abdominal cavity. A bilateral routine castration and left scrotal ablation were also performed. Two months after surgery no recurrence was noted, and the patient had normal urinary function. Inguino-scrotal bladder herniation is rare in both humans and animals. Male rabbits are predisposed to inguinal and scrotal hernias because their inguinal rings remain open throughout life. Herniation of the urinary bladder should be considered as a differential diagnosis when intact male rabbits are presented with unilateral scrotal swelling.     

Racing performance after combined prosthetic laryngoplasty and ipsilateral ventriculocordectomy or partial arytenoidectomy: 135 Thoroughbred racehorses competing at less than 2400 m (1997–2007)

Reasons for performing study: The success of combined prosthetic laryngoplasty with ipsilateral ventriculocordectomy (LPVC) has not been compared to that of partial arytenoidectomy (PA) in a clinical population. Hypotheses: In Thoroughbred (TB) racehorses: 1) earnings after LPVC are unaffected by the severity of recurrent laryngeal neuropathy (RLN) (laryngeal grade III vs. grade IV); 2) LPVC and PA yield similar results in the treatment of grade III RLN; 3) performance outcome following PA is independent of diagnosis (RLN vs. unilateral arytenoid chondritis [UAC]); and 4) neither LPVC nor PA returns horses to the level of performance of controls. Methods: Medical and racing records of 135 TB racehorses undergoing LPVC or PA for the treatment of grade III or IV RLN or UAC were reviewed. Racing records of age and sex matched controls were also reviewed. Results: After LPVC, horses with grade III RLN performed better compared to those with grade IV RLN. Furthermore, horses treated for grade III RLN by LPVC showed post operative earnings comparable to controls. Rate of return to racing were similar for PA and LPVC, although LPVC resulted in higher post operative earnings. Performance after PA was similar regardless of diagnosis (UAC or RLN). Finally, neither LPVC when performed for grade IV RLN, nor PA performed for either diagnosis restored post operative earnings to control levels. Conclusions: Thoroughbred racehorses treated by LPVC for grade III RLN show significantly better post operative earnings compared to horses treated for grade IV disease. In grade III RLN, LPVC returns earning potential to control levels. PA and LPVC lead to similar success in terms of rate of return to racing, but PA leads to inferior earnings after surgery. Potential relevance: Laryngoplasty should be recommended for all TB racehorses with grade III RLN to maximise return to racing at a high level. This contradicts the common approach of waiting for complete paralysis.     

Effect of intratesticular injection of lidocaine on cardiovascular responses to castration in isoflurane-anesthetized stallions

OBJECTIVE: To evaluate the effect of intratesticular administration of lidocaine on cardiovascular responses and cremaster muscle tension during castration of isoflurane-anesthetized stallions. ANIMALS: 28 healthy stallions (mean +/- SD age, 4.2 +/- 2.8 years) with no testicular abnormalities that were scheduled for castration. PROCEDURE: Each horse was given acepromazine (20 microg/kg, IM), romifidine (50 microg/kg, IV), and butorphanol (20 microg/kg, IV). Anesthesia was induced with ketamine (2.5 mg/kg, IV) and midazolam (50 microg/kg, IV) and maintained with isoflurane (1.7% end-tidal concentration). After 10 minutes at a stable anesthetic plane, a needle was placed in each testicle and either no fluid or 15 mL of 2% lidocaine was injected; 10 minutes after needle placement, surgery was commenced. Pulse rate and arterial blood pressures were measured invasively at intervals from 5 minutes prior to castration (baseline) until 5 minutes after the left spermatic cord was clamped. The surgeon subjectively scored the degree of cremaster muscle tension. In 2 horses, lidocaine labeled with radioactive carbon (C(14)) was used and testicular autoradiograms were obtained. RESULTS: Compared with baseline values, castration significantly increased blood pressure measurements; intratesticular injection of lidocaine decreased this blood pressure response and cremaster muscle tension. In 2 horses, autoradiography revealed diffuse distribution of lidocaine into the spermatic cord but poor distribution into the cremaster muscle. CONCLUSIONS AND CLINICAL RELEVANCE: In isoflurane-anesthetized stallions, intratesticular injection of lidocaine prior to castration appeared to decrease intraoperative blood pressure responses and cremaster muscle tension and may be a beneficial supplement to isoflurane anesthesia.     

The relationships between scrotal surface temperature,age and sperm quality in stallions

In horses, spermatogenesis normally occurs at an average intratesticular temperature of 35 °C; therefore, mechanisms for testicular thermoregulation are essential. Measuring the scrotal surface temperature by thermography is one of the methodologies used to evaluate the effectiveness of testicular thermoregulation. The objective of this study was to determine the relationship between the control of scrotal surface temperature and sperm quality in horses of different ages. In total, 24 Quarter Horse stallions were divided into three groups: YS (young stallions), AS (adult stallions) and OS (old stallions). Initially, we calculated the testicular volume (TV) and evaluated various aspects of the semen (sperm kinetics, plasma membrane integrity and sperm morphology) for all the animals. We also evaluated rectal temperature (RT), body surface temperature (BST,) and average scrotal surface temperature in the testicular region (SST) before (M0) and after sun exposure (M1). Differences were observed (p<0.05) between the RT and BST before and after sun exposure in all three groups. However, there were no differences (p>0.05) in the SST values at these two time points, thus demonstrating the efficiency of the mechanisms for testicular thermoregulation. The SST was similar (p>0.05) among all three groups. Based on these results, we conclude that fertile stallions of different age groups are able to maintain SST and measuring the heat radiating from the scrotum using a digital infrared thermographer. We can also conclude that measuring the heat radiating from the scrotum using a digital infrared thermographer is a practical and efficient tool for monitoring SST in horses.     

Laparoscopic Cryptorchid Castration in Standing Horses

Objective — This article describes a new technique for laparoscopic cryptorchid castration in standing horses. Study Design — Prospective study. Animals or Sample Population — 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 HC1 (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 combination of 2% mepivacaine and xylazine (0.18 mg/kg). Initial laparoscopic exploration was performed from the left flank; in three horses, right flank laparoscopy was needed to complete the procedure. The spermatic cord was ligated within the abdomen with one or two sutures of 0 polydioxanone suture, and the testis or testes removed through a flank incision. Results — In five horses with no palpably descended testes, standing laparoscopy was the only procedure performed, whereas in two horses, the abdominal testis was removed laparoscopically, and the descended testis was removed under short acting anesthesia. In one horse, with nonpalpable testes, it was determined by laparoscopic observation that the testes were in the inguinal canal, and castration was performed under general anesthesia. No surgical or postoperative complications were noted. The right side of the abdomen, and especially the right vaginal ring, could be easily observed from the left side by passing the laparoscope through a small perforation in the mesocolon of the descending colon or by elevating the descending colon with an instrument or by use of an arm in the rectum. Conclusions — The standing laparoscopic approach combined with or without short-acting anesthesia to remove the descended testis is easily performed. Clinical Relevance — This approach will provide surgeons with another option to castrate cryptorchid stallions.     

Aortic rupture and aorto‐pulmonary fistulation in the Friesian horse: Characterisation of the clinical and gross post mortem findings in 24 cases

Reasons for performing study: In horses, aortic sinus of Valsalva aneurysms or tears in the aortic root are well‐recognised conditions in breeding stallions, often leading to sudden death. A more uncommon form of aortic rupture, located proximal to the ligamentum arteriosum has been reported in 3 Friesian horses. Objectives: The purpose of this study was to phenotypically characterise aortic rupture and aorto‐pulmonary fistulation in Friesian horses in terms of clinical and post mortem data based on 24 cases. Methods: Friesian horses that were diagnosed with aortic rupture and aorto‐pulmonary fistulation over a period of 13 years (1997–2010) at the Department of Equine Sciences of Utrecht University (n = 15) and Wolvega Equine Hospital (n = 9), were included in this study. Case history, results of clinical examination and gross post mortem findings were screened and analysed. Results: Some cases were found dead without prior symptoms, but in several cases signs such as recurrent colic, peripheral oedema and sustained tachycardia were present for several weeks prior to cardiac failure. Clinical examination during hospitalisation revealed increased rectal temperature, peripheral oedema and increased jugular pulse with a bounding arterial pulse. In the majority of horses an aortic rupture of the aortic arch near the ligamentum arteriosum, concurrent with a circumferential cuff of perivascular haemorrhage and aorto‐pulmonary fistulation, was found at post mortem examination. Conclusions: Aorto‐pulmonary fistulation in conjunction with aortic rupture is more common in Friesians than previously estimated. In some cases findings demonstrate a progressive pathology rather than acute cardiac failure and sudden death. An appropriate approach is necessary during post mortem examination of the heart in order not to overlook the diagnosis. Potential relevance: Equine practitioners should realise that in Friesian horses presented with a history of recurrent false colic, coughing, sustained tachycardia and/or peripheral oedema, aortic rupture and aorto‐pulmonary fistulation should be included in the differential diagnosis.