Simultaneous presence of a seminoma and a leiomyoma in the testes of a horse

An 18‐year‐old stallion was presented for castration because of insidious, bilateral scrotal enlargement of one year's duration. The left testis was firm, while the right was soft and lobulated; both were larger than normal. Palpation of the scrotum and its contents did not cause the horse to show signs of discomfort. Ultrasonography of scrotal contents revealed abnormal, heterogeneous tissue with ill defined regions of hyper‐ and hypoechogenity throughout both testes. Several hours after admission the horse developed severe signs of colic. On the basis of anamnesis, clinical findings, and results of ultrasonography and transrectal palpation bilateral testicular neoplasia and incarcerated inguinal hernia were tentatively diagnosed. Because the horse's owner did not consent to surgical treatment, the stallion was subjected to euthanasia. Histological and immunohistochemical examination of the testicular tissue collected post mortem revealed a seminoma in the left testis and a leiomyoma in the right testis. The post mortem examination also revealed incarceration of the small intestine in addition to the testicular tumours. To our knowledge, this is the first report of the simultaneous presence of bilateral, yet different testicular tumour types in a stallion.     

Unilateral testicular mastocytoma in a Peruvian Paso stallion

A 12‐year‐old Peruvian Paso stallion was examined for scrotal swelling and unilateral testicular enlargement of 4–6 weeks duration. Physical examination and ultrasonography of the scrotum revealed an enlarged, nonpainful right testis with a well encapsulated mass at the cranial‐medial aspect containing echodense flocculent material. Unilateral castration was performed and the testis, spermatic cord and vaginal tunic were submitted for histological examination, which revealed a mastocytoma with accompanying evidence of malignancy. Short‐term follow‐up examination did not reveal any evidence of abdominal metastasis and the stallion has since successfully achieved pregnancy in a small number of mares. Although considered rare, mast cell neoplasia should be considered as a differential diagnosis when unilateral testicular enlargement is encountered.     

Ultrasonographic detection of chronic epididymitis in a stallion

Clinical signs of chronic epididymitis in a stallion included recurrent signs of inguinal pain--retraction of the right testis into the inguinal area, resentment of palpation of the right testis, and right-sided scrotal swelling. The tail of the right epididymis was firm and seemed to be adhered to the testis. The tail of the left epididymis felt firmer than normal. Ultrasonographically, the diameter of the head of the epididymis was considered larger than normal, was hyperechoic in relation to the right testis, and had an irregular border. Several bright 1- to 5-mm-diameter echogenic areas that alternated with less echogenic areas were seen in the head of the right epididymis. Ultrasonographic findings were interpreted as fibrosis attributable to chronic inflammation. Unilateral castration (right-sided) was performed, but the prognosis was guarded because of presumed involvement of the left epididymis.     

Bilateral Testicular Mixed Germ Cell-sex Cord-stromal Tumours in a Stallion

An 18-year-old Friesian stallion was examined approximately one week after reportedly presenting scrotal swelling due to torsion of the spermatic cords. Upon presentation no scrotal swelling was noted, the testes were normally oriented, and no abnormalities of the spermatic cords were noted. However, both testes were smaller than expected for a mature stallion and deep palpation revealed that the consistency of the testes was nodular. Ultrasonographic evaluation of the testes revealed diffuse heterogeneous parenchyma with multiple hypoechoic nodular areas. Grossly, the testicular parenchyma was effaced by multiple gray-tan nodules of varying consistency interspersed with gray-white bands of tissue. Microscopic analysis revealed multiple pleomorphic neoplastic foci disseminated throughout both testes. Histological and immunohistochemical features were atypical and consistent with the diagnosis of bilateral testicular mixed germ cell-sex cord stromal tumours. Bilateral testicular tumours and testicular mixed cell tumours are extremely rare in stallions and this is the first report of bilateral testicular mixed germ cell-sex cord-stromal tumours in a stallion. Our findings indicate that certain ultrasonographic characteristics are suggestive of testicular tumour and that immunohistochemistry markers can be used to better characterize testicular neoplasms in stallions.     

Mesothelioma of the tunica vaginalis testes in a stallion

Scrotal enlargement is a problem in stallions that often leads to poor semen quality. Although there are many causes for scrotal enlargement, testicular neoplasia is often high on the differential list, especially in an aged stallion. This case report describes a stallion with scrotal enlargement caused by a rare neoplasia located in the tunica vaginalis, and not in the testicular parenchyma. Diagnosis of mesothelioma was made following hemicastration. Prognosis in other species is variable, but this stallion returned to his successful breeding career following treatment and has remained healthy one year following the diagnosis.     

Malignant Mixed Sex Cord-stromal Tumour in a Stallion

A 30-year-old Standardbred stallion was examined for unilateral scrotal swelling. Physical and ultrasound examinations revealed a painless enlarged left testis with a non-homogeneous echogenicity, when compared with the controlateral testis. The stallion underwent left unilateral orchiectomy. Grossly, the excised testis was irregularly enlarged (12 x 9 x 9 cm; weight: 530 g) and firm. The sections showed that testicular parenchyma was replaced by a lobulated, greyish-white mass, which involved the epididymal head. At microscopy, a dual Leydig and Sertoli cell tumour component could be seen. Neoplastic Sertoli cells were prevalent and presented pleomorphic cells, mitotic figures and occasional vascular invasion. Tumour patterns showed tubular and solid areas, cord-like or diffuse in appearance, among which newly formed Leydig cell nests and low-density fibrillar bundles were interposed. Immunohistochemically, a weak to moderate immunostaining for vimentin, AE(1)/AE(3) cytokeratin, alpha-1-antitrypsin and CD99 antigens was found in the growing Sertoli cells, whose nuclear MIB-1 labelling index scored 13 +/- 2%. The Leydig tumour cells, on the other hand, displayed a moderate to strong positivity for alpha-inhibin, vimentin, AE(1)/AE(3) cytokeratin, neurone-specific enolase and CD99. On the basis of these findings, a diagnosis of malignant mixed sex cord-stromal tumour was made.     

Laparoscopic inguinal herniorrhaphy with barbed suture in a ram

A 7-month-old Hampshire ram, with no history of trauma or breeding, was referred for treatment of acute, unilateral scrotal swelling. Physical examination revealed a moderately sized, soft, left-sided, non-reducible swelling of the proximal scrotum and mild swelling of the scrotal neck. Ultrasound evaluation of the scrotum revealed morphologically normal testicles and a mild accumulation of free fluid in the left vaginal tunic. Unilateral, laparoscopic inguinal herniorrhaphy under general anesthesia was performed. The herniated omentum was reduced and barbed suture was used to imbricate the internal inguinal ring and the vaginal ring. No recurrence of herniation was reported 5 months after surgery.Key clinical message:Laparoscopic inguinal herniorrhaphy with barbed suture can be a safe and effective means of scrotal hernia resolution in a ram. When performed by a competent surgeon experienced in laparoscopy, this treatment for inguinal and scrotal herniation may minimize post-operative pain, provide a rapid return to function, and preserve normal testicular and scrotal anatomy.     

Unilateral periorchitis with a secondary peritonitis in a Standardbred stallion

A 6‐year‐old Standardbred stallion presented for evaluation of progressive diffuse scrotal swelling of 5 days' duration. Physical examination was within normal limits apart from pitting ventral oedema and severely enlarged fluid filled scrotum. Rectal examination did not reveal any abnormalities in the palpable intestinal tract, spleen, kidneys or internal inguinal rings. Testicular ultrasound examination showed evidence of abnormal right testicular parenchyma that was displaced proximally by a heteroechoic region of possible abscessation. The left testis was surrounded by a large amount of hypoechoic fluid. Abdominocentesis was performed and was indicative of peritonitis. Broad‐spectrum antimicrobials and analgesics were administered preoperatively and a bilateral open orchidectomy with closure of the external inguinal ring in addition to scrotal ablation was performed. Post operative peritoneal lavage was performed once a day for 3 days. There were no complications associated with recovery or within the immediate post operative period. The horse was released to the care of his owners 5 days following surgery and has returned to his previous racing performance level.     

Successful Treatment of Seminal Vesiculitis with Imipenem-Cilastatin in a Stallion

A 7-year-old thoroughbred stallion presented with severe colic, which was resolved surgically. On postsurgical palpation and rectal ultrasonography, the left seminal vesicle was enlarged, the left testicle and epididymis showed signs of inflammation with hydrocele. Antibiotics and anti-inflammatory treatment were administered. Fever and colic syndrome recurred, with severe inflammation of the left testis and epididymis, and unilateral orchiectomy was performed. Histopathological diagnosis confirmed chronic orchioepididymitis, and Klebsiella pneumoniae was identified and typed from all cultures. At breeding soundness examination 2 months after treatment with ceftiofur, K. pneumoniae was again isolated, and cytology revealed degenerated polymorphonuclear cells and red blood cells. Transurethral endoscopic examination was used to locate the infection in the left seminal vesicle, and ticarcillin-clavulanic was locally infused for 10 days. Nevertheless, the pathogen was once again isolated in the ejaculate, and the affected seminal vesicle was again treated locally for 5 consecutive days, using imipenem-cilastatin, a new antibiotic showing high sensitivity. Follow-up breeding soundness examination revealed an improvement in seminal characteristics and no pathogen isolation. Total pregnancy rate (31 of 36; 86%) and first cycle pregnancy rate (18 of 36; 50%) in the last breeding season reached levels similar to those prior to infection (65 of 82; 80% and 47 of 82; 57% respectively), suggesting that local treatment with imipenem-cilastatin in stallions with seminal vesicle infections is effective and, in this case, did not produce any adhesions or other undesirable effects, permitting the stallion to resume breeding with no apparent deleterious effect on fertility despite having only one testicle.     

Surgical management of duodenal obstruction in an adult horse

A 3-year-old Standardbred stallion was admitted for treatment of acute enterocolitis. The horse improved in response to empiric treatment, but subsequently developed ventral edema, scrotal abscessation, and severe laminitis. Improvement again was seen, but on day 29 of hospitalization, the horse developed rapid heart rate and signs of abdominal pain. Exploratory celiotomy revealed complete obstruction of the descending portion of the duodenum, 20 cm caudal to the duodenal sigmoidal flexure. Three-tier duodenojejunostomy and jejunojejunostomy were performed to bypass the duodenal obstruction.     

Morphometric Studies on the Testis of Korean Ring-necked Pheasant (<Emphasis Type="Italic">Phasianus colchicus karpowi</Emphasis>) during the Breeding and Non-breeding Seasons

The purpose of this study was to obtain detailed quantitative information on all cell types in the testis interstitium of Korean ring-necked pheasants and to combine these data with changes in the steroidogenic function of the testis during the breeding and non-breeding seasons. For animals collected during the breeding season, their testis weights, sperm production, serum testosterone levels and leuteinizing hormone (LH)-stimulated testosterone secretion were significantly (p < 0.01) increased compared to the non-breeding season. Testes of the pheasants during the non-breeding season displayed a 98% reduction in testis volume that was associated with a decrease in the absolute volume of seminiferous tubules (98% reduction), tubular lumen (100%), interstitium (90%), blood vessels (84%), lymphatic spaces (97%), Leydig cells (79%), mesenchymal cells (51%) and myoid cells (61%) compared to the breeding season. The numbers of Leydig cells, mesenchymal cells and myoid cells per testis in the breeding season were much higher than in the non-breeding season. Although the mean volume of a Leydig cell was 74% lower in the non-breeding season, the mean volumes of myoid and mesenchymal cells remained unchanged. These results demonstrate that there are striking differences in the testicular structure of the Korean ring-necked pheasant during the breeding and non-breeding seasons. Every structural parameter of the Leydig cell was positively correlated with both testosterone serum levels and LH-stimulated testosterone secretion. The correlation of changes in hormonal status with the morphometric alterations of Leydig cells suggests that the Korean-ring necked pheasant may be used as a model to study structure-function relationships in the avian testis.     

Sperm granuloma in a stallion

A 7-year-old stallion with a history of abdominal pain after it fell was examined and found to have a swelling of the right testis and epididymis. Semen evaluation revealed an increase in secondary sperm abnormalities. The stallion was unilaterally castrated. The histologic diagnosis was sperm granuloma, with no evidence of infection. Periductal fibrosis was observed and appeared to have developed before the trauma occurred. The changes seen could be compatible with chronic blockade of efferent ductules, resulting in extravasation of spermatozoa.     

Management Options for the Aged Breeding Stallion with Declining Testicular Function

In our experience, the testicular dysfunction that develops in aged stallions is typically progressive, contributing to a gradual deterioration in sperm output and quality over 2-4 years. As the ability to produce sufficient numbers of normal sperm in ejaculates declines, so do pregnancy rates until the stallion eventually becomes so subfertile that it is no longer commercially feasible to continue breeding. However, more intensive breeding management can sometimes result in pregnancy rates (per cycle and per season) that are sufficient to justify breeding of the aged stallion to a diminishing number of mares during the period of declining fertility.     

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.     

Conception rate at first insemination in beef cattle: effects of season, age and previous reproductive performance

The effects of season, age at previous parturition, and whether the female was retained because she failed to conceive or be detected in estrus during the previous breeding season were analyzed for first-service conception rate in beef cattle. Twelve years of reproductive data on females that were at least 50% Simmental were obtained from a single farm. All females detected in estrus were artificially inseminated during 42-d breeding seasons (52 d for heifers), starting either in June or November. The data, consisting of 9,071 first-service records, were described by a logit model and parameters were estimated using weighted least squares procedures. Age and previous reproductive performance (whether the female had failed to conceive or be detected in estrus during the previous breeding season) significantly affected first-service conception rate, as did the interaction between the two factors. Season of insemination, when considered across all other effects, did not influence first-service conception rate, but the interaction of season and previous reproductive performance was significant, as was the three-way interaction between season, age and previous reproductive performance. Except for those calving at 2.5 yr of age, females that were inseminated in the winter subsequent to parturition in the fall had the highest first-service conception rates. Those that did not conceive during the breeding season subsequent to parturition and were carried over to the following season had lower first-service conception rates, with the lowest being for females carried over to the winter breeding season.     

Lateral Branches of the Testicular Artery Affect Testicular Shape in Adult Stallions

The objective of this study was to investigate the arterial patterns of the stallion testis in relation to testicular shape. Two hundred and fifty-one stallion testes were evaluated for the presence of the lateral branches of the testicular artery. Seven specimens had their testicular arteries filled with latex milk, fixed in 70% alcohol, and dissected. Two hundred six specimens (82%) had a single testicular artery and no lateral branches; 39 testes (16%) had one lateral branch of the testicular artery; and six testes (2%) had two lateral branches of the testicular artery each. The lateral branches of the testicular artery obtained from the adult stallions, more than 5 years old, were associated with distinct lateral bulging, giving them a pear-like shape, whereas similar vascular pattern in young colts, less than 1 year old, did not cause similar shape change. Five distinct patterns of the branching of the testicular artery were determined. We concluded that the lateral branches of the testicular artery are present in approximately 20% of stallion testes. This anatomic pattern is associated with a lateral bulge that develops slowly over several years and is associated with a change in testicular shape from an ellipsoid in colts to a pear-like shape in adult stallions.     

ECHOCARDIOGRAPHIC DETECTION OF A DISSECTING AORTIC ROOT ANEURYSM IN A THOROUGHBRED STALLION

A 12-year-old Thoroughbred stallion was referred with a history of acute pain and tachycardia immediately after breeding a mare. On presentation, the horse showed no evidence of pain and routine examination of the abdomen failed to yield any abnormalities, however, a persistent tachycardia remained. A base-apex ECG examination revealed sustained ventricular tachycardia which resolved spontaneously within 12 hours of hospitalization. During this period, the stallion developed a grade 4/6 heart murmur. An aortic root aneurysm in the right sinus of Valsalva was diagnosed using two-dimensional echocardiography. Pulsed-wave Doppler evaluation revealed turbulent flow within the aneurysm. Repeat echocardiographic examination 10 months after the onset of signs revealed no change and the horse continues to perform as a breeding stallion.     

Diagnosis, surgical treatment, and performance after unilateral castration in breeding bulls: 21 cases (1989-1999)

OBJECTIVE: To evaluate signalment, surgical treatment, postoperative complications, and future breeding success or semen production in a group of bulls with naturally occurring disease of the scrotum or testis. STUDY DESIGN: Retrospective study. ANIMALS: 21 bulls that underwent unilateral castration after evaluation for scrotal swelling. PROCEDURE: A computer-assisted search of medical records at 2 veterinary teaching hospitals was performed. Historical, diagnostic, surgical, and follow-up data were collected and analyzed for those bulls with scrotal swelling that underwent unilateral castration. RESULTS: Four of 5 pasture breeding bulls and 9 of 10 semen collection-center bulls successfully bred cows or produced viable semen within 6 months of surgery. Fourteen of 21 surgical procedures were performed after induction of general anesthesia. Sixty-six percent of procedures were performed as open castrations. Seventy-one percent of bulls developed postoperative complications, most of which were mild swellings. Unilateral castration returned 13 of 15 bulls with unilateral disease of the scrotum or testis to productive service by 6 months after surgery. CONCLUSION AND CLINICAL RELEVANCE: Unilateral castration is an effective treatment for unilateral disease of the,scrotum or testis in bulls, allowing return to reproductive function.     

Method of predicting stallion to mare ratio for natural and artificial insemination programs

A method of predicting a stallion to mare ratio for horses entering either natural service or artificial insemination programs was discussed. Limiting factors for stallions in hand-breeding situations were age, libido and physical ability to cover mares presented for breeding. Other limiting factors for stallions involved in artificial breeding programs were scrotal width, daily sperm output, and the number of live spermatozoa inseminated per mare. Considerations were given for the seasonal effect upon pregnancy rate of the mare, but no considerations were made for seasonal effect upon the stallion. This method must only be applied to stallions that have undergone a thorough breeding soundness examination. It must be emphasized that it served only as a guide; the calculated values were merely useful estimates rather than firm numbers. The multitude of uncontrollable factors involved in breeding farm management, especially with regard to the mares that are presented for breeding were influences that could not be directly considered by this method.     

Azoospermia due to testicular degeneration in a breeding stallion

In a breeding stallion with azoospermia clinical andrological evaluation, transscrotal testicular ultrasonography, testicular biopsy and hormonal analysis were carried out.For differentiation of testicular versus obstructive azoospermia a testicular biopsy was carried out. The histological examination revealed testicular degeneration.