Androgen insensitivity syndrome in a thoroughbred mare (64, XY--testicular feminization)

A Thoroughbred mare was presented for stallion-like behavior. Reproductive and ultrasonographic evaluation, testosterone assays, and karyotyping confirmed a diagnosis of androgen insensitivity syndrome (64, XY--testicular feminization). Surgery to remove abdominal testicles was successful in alleviating the behavioral abnormality. This condition is discussed with reference to the current literature.     

Testicular feminization in a cat

Testicular feminization, caused by an inherited defect of the androgen receptor, was diagnosed in a domestic cat. Individuals affected with this syndrome are genetic males that have testes but fail to undergo masculinization because the internal and external genitalia cannot respond to androgens. The affected cat had the external appearance of a sexually normal female, but during surgery for ovariohysterectomy, only 2 abdominal gonads were found. Müllerian (uterus) or wolffian (epididymides) derivatives were not present. Only testicular tissue was found in histologic sections of the gonad. A normal male chromosome constitution (38,XY) was found in karyotypes prepared from lymphocyte cultures. High affinity binding of dihydrotestosterone was undetectable in fibroblasts cultured from genital skin of the affected cat, indicating that the cytosolic androgen receptor was nonfunctional. Pedigree analysis indicates that this is an X-linked disorder in cats, as it is in other mammals. Accurate diagnosis and genetic counseling are advocated to reduce the prevalence of the disorder.     

Laparoscopic Gonadectomy in Two Intersex Warmblood Horses

Two phenotypically female Warmblood horses were presented at the Clinic for Horses owing to stallion-like behavior. One mare had an enlarged clitoris, whereas the other one showed no signs of ambiguous external genitalia. In both cases, intra-abdominal testicles were removed by laparoscopy. Hormone status, cytogenetic evaluation, and histopathological examination of the gonads were performed. One animal was diagnosed as having XX disorder of sexual development; the other one, as male pseudohermaphrodite.     

Die testikuläre Feminisierung beim Rind als Sterilitätsursache von Färsen

As a contribution to knowledge of anoestrus in heifers, a case of testicular feminisation in a Friesian heifer is reported. This is the first case of this unusual intersex form in German breeds of cattle. 2. The genital syndrome “testicular feminisation” originates in genotypically male animals with foetal testicular insufficiency resulting in diminished or absent androgen production. For this reason, despite the male karyotype, phenotypically female individuals develop with normal female external genitalia, but lacking a uterus and having a short vagina. The male internal organs are also absent, apart from the large intra-abdominal testes. 3. Testicular parenchyma and tubular epithelium are arrested in a state of embryonic development, with severe degeneration of the tubular epithelium which do not contain cells at more developed stages of spermiogenesis. 4. Testicular feminisation is genetically conditioned and is due to a recessive, sex-linked gene which is transmitted by female animals. The frequency of occurrence of this gene and the incidence of the defect in the population appear to be very low.     

Endocrine and sperminogenic testicular function. 7. Relationship between testicular and plasma androgen concentrations in boars of different ages]

Testicular tissue and blood samples (V. spermatica interna) were taken from 32 boars during castration. The animals were of different age groups. Against this background, comparative studies were conducted into the relationships between testicular and plasma testosterone. A very close correlation was found to exist between the androgen values in testicular tissue and those in the blood plasma of V. spermatica interna (r = 0.9795), wich appeared to support the conclusion that by determination of blood plasma the androgen content in the testes can be established with high probability.     

First Description of Scrotal Testicles in a Dog Affected by 78, XX Testicular Disorder of Sex Development

An eight‐month‐old female dog presented with ambiguous external genitalia. A thorough clinical examination together with various imaging techniques and a histology examination showed the presence of two testicles linked to both the Mullerian and Wolffian ducts. The discovery of the 78,XX SRY‐negative karyotype led to the diagnosis of incoherence between the chromosomal and gonadal sex, which is typical for a 78,XX testicular disorder of sex development. Our case was unique because the testicles were still located in their normal scrotal position, whereas the literature contains reports of the presence of cryptorchid testicles in this karyotype setting. To our knowledge, this is the first case that describes an SRY‐negative 78,XX testicular disorder of sex development with bilateral scrotal testicles.     

Presumptive Sry-negative XX sex reversal in a llama with multiple congenital anomalies.

Multiple congenital abnormalities of the external genitalia consistent with XX sex reversal were detected in a juvenile llama. The llama had a typical female karyotype (74, XX) and did not have a Y chromosome, but a minute chromosome was detected. To determine whether a piece of Y chromosome containing the Sry gene might be located in a small translocation, DNA analysis by polymerase chain reaction was performed; the Sry gene was not detected. Histologic examination revealed ovarian tissue, whereas testicular tissue was not found. External genitalia were partially masculinized, indicating that the urogenital sinus, genital tubercle, and genital swellings had been exposed to androgens during development, although the dam had not received exogenous androgens. Testicular tissue in the ovaries may have been undetected or had regressed prior to birth, as has been reported in sex reversal in mice.     

Sequence variations in equine candidate genes For XX and XY inherited disorders of sexual development

Inherited disorders of sexual development (DSD) cause sterility and infertility in horses. Mutations causing such disorders have been identified in other mammals, but there is little information on the molecular causes in horses. While the equine genome sequence has made it possible to identify candidate genes, additional tools are needed to routinely screen them for causative mutations. In this study, we designed a screening panel of polymerase chain reaction primer pairs for 15 equine genes. These are the candidate genes for testicular or ovotesticular XX DSD and XY DSD, the latter of which includes gonadal dysgenesis, androgen insensitivity syndrome (AIS), persistent Mullerian duct syndrome and isolated cryptorchidism. Six horses with testicular or ovotesticular XX DSD and controls were screened. In addition, candidate genes for androgen insensitivity syndrome, persistent Mullerian duct syndrome and isolated cryptorchidism were screened in normal horses. While no sequence variants were uniquely associated with XX DSD, the 38 sequence variants identified can serve as intragenic markers in genome-wide association studies or linkage studies to hasten mutation identification in equine XX DSD and XY DSD.     

Serial percutaneous testicular biopsy in the Beagle dog

The effects of serial percutaneous testicular biopsy on testicular size, semen characteristics and plasma testosterone have been assessed. Testicular atrophy occurred in one dog after the first biopsy, but apparently there were no permanent deleterious effects on semen characteristics or testosterone concentrations. The histological changes 72 hours and 14 days after bilateral testicular biopsy were examined in one dog. Initial haemorrhage and necrosis with subsequent fibrosis and atrophy occurred at the biopsy site. The surrounding tissue remained normal in appearance. The technique may be worthwhile for establishing diagnostic criteria in cases of male canine infertility. Not enough tubules are obtained in circular cross-section to allow detailed histomorphometric analysis of spermatogenesis under laboratory conditions.     

XY male pseudohermaphroditism in a captive Arabian oryx (Oryx leucoryx).

A 2-yr-old Arabian oryx (Oryx leucoryx) was presented for evaluation of abnormal genitalia and infantile behavior. The oryx had a penis and a scrotum, but testes were not palpable within the scrotum or inguinal canal. The total serum testosterone for the individual was lower than in age-matched males of the same species. Surgical exploration showed markedly hypoplastic intra-abdominal gonads, which demonstrated both testicular and uterine tissue on histologic examination. After karyotype analysis, the individual was classified as an XY male pseudohermaphrodite. This condition resembles two human intersex syndromes: embryonic testicular regression syndrome and partial gonadal dysgenesis syndrome, which occur in familial lines.     

Male pseudohermaphroditism in a Labrador Retriever, and a review of mammalian sexual differentiation

CASE HISTORY: An 8-month-old Labrador Retriever was referred with a history of ambiguous external genitalia. CLINICAL FINDINGS AND TREATMENT: Clitoromegaly within apparent vulval folds, and an adjacent subcutaneous mass were noticed on external examination. An intra-abdominal testicle, with epididymis and suspected vas deferens ducts, was found during exploratory celiotomy. Incision over the subcutaneous mass revealed the accompanying testicle. Clitoridectomy was performed and an os clitoris removed. Normal juvenile testes were diagnosed on histology of the gonads. Chromosomal studies revealed a normal 78, XY male chromosomal constitution. Due to the combination of a male karyotype (78, XY), the presence of testicular tissue in the gonads, and the appearance of the external genitalia, a diagnosis of male pseudohermaphroditism (MPH) was made. CLINICAL RELEVANCE: This case presents the first report of MPH in a Labrador Retriever, and highlights the diagnostic steps recommended when confronted with a dog with ambiguous external genitalia.     

Male pseudohermaphroditism in a Labrador Retriever,and a review of mammalian sexual differentiation

CASE HISTORY: An 8-month-old Labrador Retriever was referred with a history of ambiguous external genitalia.

CLINICAL FINDINGS AND TREATMENT: Clitoromegaly within apparent vulval folds, and an adjacent subcutaneous mass were noticed on external examination. An intra-abdominal testicle, with epididymis and suspected vas deferens ducts, was found during exploratory celiotomy. Incision over the subcutaneous mass revealed the accompanying testicle. Clitoridectomy was performed and an os clitoris removed. Normal juvenile testes were diagnosed on histology of the gonads. Chromosomal studies revealed a normal 78, XY male chromosomal constitution. Due to the combination of a male karyotype (78, XY), the presence of testicular tissue in the gonads, and the appearance of the external genitalia, a diagnosis of male pseudohermaphroditism (MPH) was made.

CLINICAL RELEVANCE: This case presents the first report of MPH in a Labrador Retriever, and highlights the diagnostic steps recommended when confronted with a dog with ambiguous external genitalia.     

Equine granulosa cell tumors.

Unilateral ovariectomy was performed on 3 mares affected with granulosa cell tumors. Tumor fluid in each mare was found to contain estrogen, testosterone, and progesterone. In 2 mares, preoperative blood plasma concentrations of these hormones were comparable to those of a series of clinically normal mares. The other mare, which had a history of aggressive, masculine behavior, had higher testosterone content in the tumor fluid and in the preoperative blood sample. After surgical removal of the tumors, each mare developed follicles and ovulated with the remaining ovary. Each was eventually bred and 2 conceived. The probability of metastasis of these tumors in mares appears uncertain. Data from other species suggests a guarded long-term prognosis may be justified.     

Diagnosis and surgical removal of a granulosa-theca cell tumor in a mare

An 8-year-old mare showed stallion-like behavior and aggressiveness. A granulosa-theca cell tumor was tentatively diagnosed based on history, transrectal palpation, and ultrasonography, and surgically removed. Serological levels of testosterone and inhibin were elevated. Histopathological examination confirmed the diagnosis. The mare recovered and by day 45 could be turned out with other horses.     

Use of a hand-assisted laparoscopic technique for removal of a uterine leiomyoma in a standing mare

A 20-year-old Thoroughbred mare was evaluated because of a 2-year history of infertility. The mare had normal estrous cycles and had been bred 7 times by different stallions. Ultrasonographic examination revealed a homogeneous hyperechoic intramural mass in the tip of the right uterine horn; the mass was also detected via hysteroscopy Unilateral ovariectomy and partial hysterectomy were performed by use of a hand-assisted laparoscopic technique. Leiomyoma was diagnosed via histologic examination of the mass. Unilateral ovariectomy and partial hysterectomy are recommended in mares with leiomyoma in a uterine horn, especially if the tumor is associated with infertility. The hand-assisted laparoscopic technique allows direct visualization of abdominal structures and accurate placement of ligatures without applying tension on the broad ligament, and eliminates the risks and costs of general anesthesia.     

Testicular fine needle aspiration cytology as a diagnostic tool in dog infertility

The results of testicular aspirate cytology taken from clinical patients with a history of infertility were compared with the clinical and histological findings. Azoospermia was the most common and the most rewarding indication for the examination. Samples were also taken from cases with suspected testicular tumours, orchitis, epididymitis, severe oligo- and teratozoospermia, lack of libido and unilateral testicular atrophy. Histological and cytological findings were found to correlate well. Identification of cell types from normal germinal epithelium was relatively easy. No Immediate adverse effects of aspiration were noted. Five normospermic dogs were monitored for two to six months after aspiration, and there were no marked deleterious effects on testicular consistency, testicular histology or semen characteristics. Testicular cytology obtained by fine needle aspiration may, at least to some extent, be used to assist clinical diagnosis, especially In azoospermlc dogs and dogs with palpable changes of testicular tissue.     

Pathological Conditions of the Reproductive Organs of Male Stray Dogs in the Tropics: Prevalence, Risk Factors, Morphological Findings and Testosterone Concentrations

The objective of this study was to estimate the prevalence of and risk factors for pathological conditions of the reproductive organs in stray dogs under tropical conditions. Three hundred and eighteen dogs were examined post-mortem in the period from 1 July 2002 to 30 June 2003. Before killing, a blood sample (from the cephalic vein) for testosterone assay was taken. Pathological conditions of the reproductive organs were found in 135 of the dogs (42.5%) and in 175 of the testes (64.8%). The most frequent pathologies found were testicular degeneration, cryptorchidism, testicular hypoplasia and testicular tumours (in 15.1%, 6.6%, 6.6% and 5.4% of the dogs and 15.1, 4.6, 6.0 and 3.5 of the testes, respectively). Transmissible venereal tumour (TVT) was seen in 5.4% of the dogs. Testicular degeneration was more common in old dogs and underweight dogs (p < 0.05). Testicular tumours were 14.3 times more common in cryptorchid dogs. Age was another important factor for the development of testicular tumours (p < 0.05). Lower levels of testosterone concentration (p < 0.05) were observed in dogs with advanced testicular degeneration (0.7 +/- 0.8 nM), dogs with hypoplastic testicles (0.8 +/- 0.9 nM) and dogs with one degenerated and one retained testis or with bilateral cryptorchidism (1.2 +/- 0.9 nM) compared to dogs with one or two normal testes (7.0 +/- 5.5 nM). Testicular volume and weight were significantly lower in degenerated, hypoplastic and retained testes compared with the contralateral normal testis. Some spermatogenic activity was found in three of the retained testes, producing oligozoospermic smears with a high percentage of sperm abnormalities. No comparable epidemiological data about male pathological conditions of the reproductive organs in the dog is available. The prevalence found in this study, yet, appears high.     

Male pseudohermaphroditism in a cat

A seven-month-old male pedigree cat was brought to the Norwegian College of Veterinary Medicine for routine castration. Visual examination of the external genitalia revealed a wide genital cleft with non-fused bilaterally located testicular pouches. A large clitoris, which was penis-like with small penile spines, was seen protruding dorsally from the ventral commissure of the genital cleft. During an exploratory coeliotomy, no intra-abdominal genital structures of müllerian origin were found. The skin pouches on either side of the vulvar cleft were incised and grossly normal testicles were removed. Histology of the removed gonads showed no or very sparse spermatogenesis. The chromosomal sex was determined by karyotyping to be a normal male 38XY. Based on these findings, the diagnosis of male pseudohermaphroditism was made. The aetlology of the condition in this cat was not determined.     

Testicular changes observed in boars following experimental inoculation with pseudorabies (Aujeszky''s) virus.

Four boars were inoculated intranasally with pseudorabies virus to determine if microscopic testicular changes occurred as a result of infection. Testicular biopsies and semen samples were taken at two, four and six weeks postinoculation and the boars were castrated immediately after the last sample collection. Testicular samples and semen were cultured to determine if the virus was present. Pseudorabies virus was not isolated from the semen or testicular tissue. Virus was isolated from trigeminal ganglia at necropsy and from nasal swabs taken one day after castration. Consequently, a time of high risk for shed of the virus from clinically normal carrier animals is immediately following castration. Gross changes were not observed in testicular tissues and microscopic changes in the testicles were the result of biopsy. Lesions consistent with pseudorabies virus infection were observed in the central nervous system of all inoculated boars. Temporary lowered fertility may result from the effects of elevated body temperature on spermatogenesis during acute clinical disease. However, it appears that the strain of pseudorabies virus used, lacked the ability to infect and/or replicate in the boars' reproductive tracts.     

Laparoscopic-assisted castration of a monorchid male pseudohermaphrodite pony

A pseudohermaphrodite possesses gonads of one sex, but with external genitalia of the opposite sex. Although cases of male pseudohermaphroditism have been published, there is no report of a monorchid male pseudohermaphrodite. This Case Report documents a 12-year-old monorchid male pseudohermaphrodite displaying stallion-like behaviour, with an elevated serum oestrone sulphate concentration confirming the presence of functional testicular tissue. A complete resolution of all behavioural signs occurred after laparoscopic-assisted castration under general anaesthesia, along with a drop in serum oestrone sulphate concentrations to <0.01 ng/ml and no response in serum testosterone concentration following administration of hCG.