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.     

Unilateral Seminoma in a Dromedary Camel

A 10‐year‐old, clinically healthy, male dromedary camel had presented a history of progressive unilateral testicular enlargement over the past 5 years. The animal had mated with 32 females during that period; all had conceived. The sex ratio of his offspring was one male to 31 females. Ultrasound examination of the right testicle revealed a diffusely heterogeneous parenchyma with no identifiable normal testicular tissue. The enlarged testicle was surgically removed. Macroscopically, the testicle had a glistening pink surface and contained multiple soft, bulging nodules. Histopathologically, a well‐differentiated, diffuse seminoma was diagnosed. In conclusion, this study describes the fertility, sex ratio, clinical findings and ultrasonographic imaging in a male dromedary camel affected with unilateral testicular seminoma.     

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.     

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.     

Recurrent torsion of the spermatic cord and scrotal testis in a stallion

A stallion was twice referred for evaluation of scrotal swelling and signs of pain. The first admission followed a 3-year period of recurrent signs of left-sided scrotal pain and swelling. After the removal of the left testis because of testicular torsion, the stallion was returned to service. The conception rate was 82% for the next breeding season. Two years after initial surgery, the stallion again was evaluated because of acute signs of right-sided scrotal pain and swelling. Right-sided testicular torsion was detected and corrected, and the testis was sutured in place. The stallion's conception rate for the following breeding season was greater than 90%.     

Salmonella typhimurium abscess as a postoperative complication in a horse with colic.

An 11-year-old, 430-kg fox-trotter stallion was referred for evaluation of colic. A right-sided inguinal hernia was diagnosed. At exploratory laparotomy, the ileum was found to be herniated through the right inguinal canal. Compromised small intestine was resected, jejunocecal anastomosis was performed, and the horse was castrated. Three days after surgery, the stallion would not bear weight on the left hind limb. The musculature of the left thigh region became swollen. Aspiration of the left thigh region yielded serosanguineous fluid from which Salmonella typhimurium was isolated. Ultrasonography of the left thigh revealed multiple hypoechoic areas suggestive of abscess. The left medial thigh region was surgically incised, and a large abscess was drained. Bacteriologic culture of feces yielded S typhimurium. The owner elected to have the horse euthanatized.     

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.     

Production, behaviour and fertility of Merino wethers, hemi-castrates with reduced testicular parenchyma and induced cryptorchids

Greasy wool production, body weight, behaviour and fertility of male, fine wool Merino sheep were studied from 10 to 21 months of age to assess their suitability for wool production. The males were either castrated (wethers), or were hemi-castrated with a vasectomy and reduction (either partially or in full) of the parenchyma of the retained testicle, or the testicles pushed up into the ingulnal canal and the scrotum shortened (induced cryptorchids). There were significant differences among all groups in body weight, with increases being associated with the larger amounts of testicular tissue present. Fertility was low in the induced cryptorchids at 19 months of age. The hemi-castrates with reduced testicular parenchyma were infertile. The hemi-castrates with reduced testicular parenchyma had significantly heavier greasy fleece weights than the wethers and induced cryptorchids, which had similar fleece weights. The wether group suffered a higher prevalence of posthitis in spring and autumn than the hemi-castrate or induced cryptorchid groups. Those hemi-castrates with the largest amount of testicular parenchyma retained and the induced cryptorchids exhibited masculine behaviour patterns and had an increased incidence of fly strike to the head. The principle of hemi-castration and reduction of the testicular parenchyma is shown to be applicable in wool producing flocks with the potential to increase greasy wool production while minimising the management and marketing limitations previously associated with induced cryptorchids.     

TESTICULAR ULTRASOUND IN THE NORMAL DOG

The testicles of ten dogs presented for routine castration were imaged with real time ultrasound. A scanning technique using multiple imaging planes (sagittal, transverse, and dorsal planes) was developed to image the testicles and epididymi. The testes were characterized by a coarse medium echo pattern. The mediastinum testis was consistently seen as a 0.2 cm wide linear hyperechoic structure in the central long axis of the testis. The ability to identify and the appearance of the epididymis was variable. The tail was consistently seen as an anechoic to hypoechoic structure. Ultrasound images were compared for anatomical structure with frozen gross sections. Ultrasonic and gross measurements were made and analyzed. Individual gross and ultrasonic measurements compared favorably. Linear regression coefficients between body surface area versus testicular length and diameter were 0.73 and 0.58 respectively. A Wilcoxin signed rank test for similarity p = 0.33 value was found when comparing the right to the left testicle.     

Complications from a testicular prosthesis in a stallion

A testicular prosthesis was removed from the scrotum of a 3-year-old Quarter Horse stallion. The prosthesis had been placed in the left side of the scrotum 10 months earlier, after an unsuccessful attempt to reposition the retained left testis. Because of a persistent draining fistula on the scrotum, first noted 5 months after placement of the prosthesis, surgery was performed to remove the prosthesis. At surgery, the left testis was found in a fibrous mass surrounding the prosthesis. The left testis had descended after placement of the prosthesis, and its involvement in the fibrous tissue surrounding the infected prosthesis necessitated its removal. Had the prosthesis not been placed, descent of the left testis probably would have resulted in an essentially normal stallion.     

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.     

Testicular Neoplasms (Interstitial and Sertoli Cell Tumours) in a Domestic Ferret (Mustela putorius furo)

Unilateral testicular enlargement was detected in a 5‐years‐old domestic ferret during a routine sterilization. The right testicle showed two different types of proliferative lesions: (i) round nodules, well demarcated, showing a soft yellow tissue; (ii) white nodules, firm, with irregular‐shaped invaginations. Microscopically, the neoplastic proliferations were identified as an interstitial neoplasm and Sertoli cell tumour, respectively. The left testicle was small and showed intense testicular atrophy. Clinical evaluation of the ferret did not show any other apparent pathological processes. This study is the first case reporting the concomitant occurrence of a Sertoli cells tumour and an interstitial cell tumour in a domestic ferret.     

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.     

B-MODE AND DOPPLER ULTRASOUND IMAGING OF THE SPLEEN WITH CANINE SPLENIC TORSION: A RETROSPECTIVE EVALUATION

The ultrasonographic appearance of splenic torsion has been described; the splenic parenchyma can be normal, hypoechoic or anechoic with interspersed linear echoes (coarse/"lacy" appearance). The ultrasonographic parenchymal appearance of 15 dogs in this report with splenic torsion varied: mottled hypoechoic regions (n=2), diffusely hypoechoic (n=11) and normal (n=2). Because splenic torsion causes vascular congestion due to splenic vein compression and eventual thrombosis, visible splenic vein intraluminal echogenicities compatible with thrombi were seen in 13 dogs using B-mode. Using spectral Doppler and color Doppler imaging of the splenic veins, no measurable flow velocities were detected in any of the 15 dogs. The varied B-mode ultrasonographic appearance of the splenic veins for intraluminal echoes and spectral or color Doppler evaluation for absent velocity flow.     

Halicephalobus gingivalis (H. deletrix) infection in two horses in southern California.

Two horses, a 16-year-old male Holsteiner and a 5-year-old male miniature horse, were diagnosed with halicephalobiasis at the California Veterinary Diagnostic Laboratory System, San Bernardino Branch, in April and June of 1998. Over a period of 4 weeks, the Holsteiner horse developed renal dysfunction, blepharospasm, and blindness in the right eye. A 15-cm-diameter mass was detected on ultrasound examination in the right kidney. Terminally, the animal developed seizures and was euthanized. The miniature horse had a 6-week-long illness characterized by testicular enlargement and uveitis. This animal developed ataxia and died. Necropsy examination revealed bilateral enlargement of the kidneys in both horses, petechial hemorrhages of the optic nerve (Holsteiner), and a diffusely firm and enlarged left testicle (miniature horse). Microscopic evaluation of tissues revealed granulomatous nephritis, optic neuritis, retinitis, and encephalitis in both horses and orchitis in only the miniature horse with intralesional rhabditiform nematodes. Halicephalobus gingivalis was found in the urine sediment of both animals and in semen of the Holsteiner horse.     

Use of ultrasonography to diagnose Sertoli cell neoplasia and cryptorchidism in a dog

Unilateral cryptorchidism and Sertoli cell tumor in the descended testis were provisionally diagnosed by use of ultrasonography in a 7-year-old Keeshond. The left testis was thought to have degenerated, but ultrasonography of the scrotum did not reveal evidence of testicular or epididymal tissue. The contralateral testis contained a hypoechoic mass believed to be a testicular tumor. Surgery and histopathologic findings confirmed the diagnosis. Ultrasonography of the scrotum and its contents should be considered for use in animals with suspected testicular neoplasia and/or degeneration.     

Granular cell tumor in the testis of a rabbit: cytologic, histologic, immunohistochemical, and electron microscopic characterization

An adult pet rabbit (Oryctolagus cuniculus) presented with a progressively enlarging left testicle. Because neoplasia was suspected, the testicle was removed. Pathologic evaluation (exfoliative cytology, histopathology, immunohistochemistry, electron microscopy) indicated that the tumor was an intratesticular granular cell tumor. Granular cell tumor has not been described in rabbits before and has not been described in the testes of animals or postnatal humans. Granular cell tumor should be included as a differential diagnosis of testicular tumors, particularly Leydig cell tumor, because of potential histologic similarities.     

Testicular neoplasia in the retained testicles of an intersex male dog

This case describes the presentation and management of an 8 yr old phenotypically female intersex male dog presented for evaluation of a mass in the right inguinal region. The right inguinal space was surgically explored, and a large irregular mass resembling a fully developed testicle was identified in the right vaginal tunic. A second mass resembling an atrophied, but anatomically mature testicle, was identified in the left tunic. The larger mass was identified as a Sertoli cell tumor that had replaced all normal testicular tissue. The smaller mass was identified as a testicle that contained a small intratubular seminoma. The patient was diagnosed as having a phenotypic female sex, chromosomal male sex, and a gonadal male sex. Hormone assays completed before and after the gonadectomy and mass removal document an elevation of circulating progesterone presurgically that returned to baseline by 1 mo postsurgically. The source of the progesterone was identified to be the Leydig cells of the atrophied testicle.     

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.     

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.