Multiple Congenital Genitourinary Anomalies in a Polled Goat WILLIAM W. KING, DVM, PHD, DIPLOMATE, ACLAM,1,2* MELVIN E. YOUNG,1 AND M. EUGENE FOX, DVM3 A 1-day-old, Toggenburg/Nubian crossbred goat of polled parentage was referred for necropsy because of a large (diameter, 5 cm) bladder-like mass protruding from the perineal midline and difficult urination. Differential diagnoses included cutaneous cyst, ectopic urinary bladder, and urethral diverticulum/dilatation. Several genitourinary aberrations were noted. A second, smaller (diameter, 1 cm), more distal cystic structure was adjacent to an ambiguous prepuce. Testicles were discovered within a con- stricted, subcutaneous space near the inguinal canals. A rudimentary penis was located dorsal to the penile urethra with no appreciable urethral process. A tiny external urethral orifice was discerned only after liquid was injected into the lumen of the cystic structures, confirming their identity as urethral dilatations. The dilatations were separated by a constricting band of fibrous tissue. No other significant findings were detected. This case illustrates a combination of congenital anomalies including bilateral cryptorchidism with scrotal absence, segmental urethral hypoplasia, and urethral dilatation, most likely associated with the intersex condition seen in polled breeds. The continued production and use of small ruminants as animal models demands the prompt recognition of congenital anomalies. This case also exemplifies the precautions required when breeding goats with polled ancestry. The domestic goat (Capra hircus) has historically served and Nubian/Toggenburg sire. The owner reported that the doe had continues to play an important role in biomedical research (1). completed a normal gestation period on a diet of natural grass/ Many small breeds are available, facilitating common labora- alfalfa hay and water. The surviving twin appeared to be a nor- tory animal husbandry practices. Because of their large, easily mal male. accessed jugular veins, goats frequently are used in the produc- Upon initial gross examination, the kid appeared in good tion of antiserum. Along with sheep (Ovis aries), these small nutritional status. The prepuce demonstrated shared charac- ruminants are common subjects in reproductive studies. Be- teristics of female and male, with the preputial opening located cause of their natural affinity for caprine arthritis-encephalitis intermediately between that expected of a male or female. The virus, goats also are used to investigate the pathogenesis of prepuce was characterized as a small (approximately 1 cm) lentivirus infection. This species has been specifically recom- opening in the ventral abdominal skin, exposing a slightly mended as a spontaneous animal model for the following globoid, reddened mucous membrane with little recognizable human diseases: congenital hypothyroidism (2), neuritic structure. A small (approximately 0.2 × 1.0 cm) cartilaginous plaques (secondary to scrapie; 3), pulmonary adenomatosis structure was palpable dorsal to the prepuce. No urethral pro- (jaagziekte, or alveolar cell carcinoma; 4), amelia, or congeni- cess was present in the prepuce, and no other external genitalia tal absence of limbs (5), and glomerulonephritis (6). were identifiable. Many conditions are known to be inherited in various goat A 5-cm, vascularized, bladder-like mass extended from the breeds, including afibrinogenemia (Saanen), beta-mannosidosis ventral perineal midline (Fig. 1). A similar, smaller (approxi- (Nubian), bipartite scrotum (Angora), brachygnatha or abnor- mately 1 cm) structure was located adjacent to the prepuce. The mally shortened mandible, cryptorchidism (Angora), excessive two were separated by a constricting band of fibrous tissue just facial hair (Angora), gynecomastia or excessive development of proximal to the area of the preputial urethra. The surface of male mammary glands, hereditary goiter (Dutch), inherited these thin-walled structures was smooth with no evidence of hair abortion (South African Angora), the spasm-inducing disorder or other skin adnexa. A tiny external urethral orifice was recog- myotonia congenita, recessive atrichosis or hairlessness, nized only after liquid was injected into, and expressed from, Robertsonian translocation, short tendons (Australian Angora), the bladder-like mass. Dissection revealed that the lumen of these sperm granulomas, supernumerary teats, and testicular hypo- structures was confluent with the pelvic urethra. plasia (7). Although numerous congenital disorders have been Upon further examination, testicles were discovered within a reported in goats, the presence of multiple anomalies in a single short inguinal canal confined within the subcutis (Fig. 2). Grossly, case is rather rare (8). This case report describes a combination the testes appeared normal, although the ductus deferens ap- of abnormalities most likely associated with the intersex condi- peared distended throughout the length of the colliculus tion in a polled kid. seminalis to the epididymis. No indication of a scrotum was evi- dent. No rudimentary ovarian or uterine structures were located, Case History and no other lesions were appreciated grossly. A 1-day-old goat was referred for necropsy because of dysuria Differential diagnoses for the larger bladder-like structure and a large bladder-like mass extending from the ventral perineal included cutaneous cyst, ectopic urinary bladder, and urethral midline. The animal was examined by the referring veterinar- dilatation or diverticulum. Dissection of the perineum confirmed ian; euthanasia was elected and performed on-site. The kid was that both structures constituted dilatations/diverticula of the one of a pair of twins from a polled Toggenburg dam and polled perineal urethra. Further exploration identified the urethral lumen from the urinary bladder to the small external urethral orifice (Fig. 3). Gross observations were consistent with the di- 1Research Service (151), Department of Veterans Affairs, Edward Hines Jr. VA Hospital, agnoses of bilateral cryptorchidism, segmental urethral 2 Hines, Illinois 60141; Department of Pathology, Loyola University Medical Center, Maywood, hypoplasia, and urethral diverticula. Illinois 60153; 3House-Call Veterinary Service, Lockport, Illinois 60441 *Corresponding author: William W. King, DVM, PhD, Diplomate, ACLAM, Office of The preputial ambiguity strongly suggested a genetic condi- Research Services, School of Medicine, University of Louisville, Louisville, Kentucky 40292 tion involving reproductive development. In neonatal ruminants, Volume 41, No. 5 / September 2002 CONTEMPORARY TOPICS © 2002 by the American Association for Laboratory Animal Science 39 Figure 3. Dissected genitourinary tract of affected goat. A catheter has been inserted through the urethra into the urinary bladder. A, external urethral orifice; B, large urethral diverticulum; C, seminal colliculus; D, small urethral diverticulum. Discussion Congenital abnormalities. Developmental anomalies may re- sult from both genotypic and environmental influences, or a combination of both, with an interruption of the “temporal-spa- tial requirements of development” (10). Congenital or hereditary abnormalities of the urethra occur infrequently in all animal species and include malformations of the urethral wall and ori- fice (e.g. hypospadias, epispadias with exstrophy or eversion of the bladder), urethral aplasia and agenesis, ectopic urethra, ure- thral duplication, and urethrorectal or urethrovaginal fistula (11, 12). In goats, inherited anomalies associated with the distal uri- nary tract and/or reproductive tract include bipartite scrotum Figure 1. External appearance of anomalies. Note the two ventral mid- and cryptorchidism in Angora goats, testicular hypoplasia, sperm line cyst-like masses and the ambiguous prepuce. granulomas, and intersex (7). Reports of urethral diverticula in neonatal goats are uncom- mon. In one description, a 2-day-old goat of unspecified breed presented for urinary obstruction with a urethral diverticulum (confirmed via positive contrast urethrography), bipartite scrota, and preputial hypoplasia with an imperforate urethral process (8). Although no etiology was determined, surgical correction (urethrostomy, obliteration of the diverticula, and castration) was effective. In a report of 11 goats between 2-6 months of age that presented with continuous dribbling of urine, congenital urethral diverticula were discovered and successfully treated by surgical resection. Ten of the kids, which were of unstated breed, also had scrotal anomalies, including bipartite scrotum and monorchidism (13). Although the term “pseudohermaphrodite” has been used to describe animals retaining the gonads of one gender with sex characteristics of the other, such as genotype or reproductive morphology (14), the preferred term for gender inconsisten- Figure 2. Location of cryptorchid testicle (A) in subcutaneous inguinal cies in goats is “intersex” (7). This condition results from sex canal (B, vaginal ring). chromosomal abnormalities and has been defined as “ambigu- ity in the structure of the gonads, reproductive tract, or external the distal aspect of the penis, including the urethral process in genitals” (14). The disorder is strongly associated with the polled goats, is adhered to the prepuce (9). However, the testicles nor- condition in goat breeds of western European descent (Saanen, mally are descended at birth into a well-developed scrotum (7). Alpine,