Surgical management of perineal hypospadia in a dog. (Short Communication).
Hypospadia is a congenital anomaly of external genitalia, in which there is fusion failure of urogenital folds and incomplete development of penile urethra. The condition is rare and the etiology is unclear. This anomaly can occur anywhere from penis to perineum and is often associated with failure of fusion of prepuce and under development or absence of penis. It can be classified as mild, moderate and severe form (Hobson, 1998). In severe cases, lesions like under development or absence of penis, failure of fusion of scrotum and failure of urethra to close in perineal area may be seen. Other abnormalities associated with hypospadias such as retained testicles, bifid scrotum as in the present case, renal agenesis, bone or anorectal defects, umbilical hernia, hydroencephalus and urinary incontinence (McFarland and Deniz, 1961 and Hobson, 1983). There are relatively few reports of this condition in the Veterinary literature, the present case paper reports successful surgical treatment of hypospadias in dog.
History and Observation
A three year old, crossbred dog, weighing 13 kg was presented with history of urinary incontinence for past 3 days. The owner reported that animal was having abnormal location of penis and scrotum. On physical examination, there was bifid scrotum with exposed penis (Fig. 1) and urinary scald around the ventral abdominal skin. The preputial sheath was absent from bulbus glandis to tip of penis but dorsal mucosa of the incompletely formed sheath was present at ventral abdominal wall. The penile urethra was opening 5cm behind the tip of penis. The exposed penis was dry and inflamed. There were no evidence of neurological deficits and signs in animal. A urinary catheter was introduced into abnormally located urethral opening to find out patency. A lateral survey and contrast radiographs were taken and confirmed normal patency. Corrective surgery was performed to reconstruct the preputial sheath.
Treatment and Discussion
The animal was premedicated with Atropine sulphate and Xylazine hydrochloride @ dose rates of 0.04 mg/kg b.wt. and 1.0 mg/kg b.wt. intramuscularly, respectively. Anaesthesia was induced with 2.5% Thiopentone @ dose rate of 10 mg/kg b.wt. intravenously and maintained with Isoflurane. A lateral incision was made in mucocutaneous junction on either side of midline up to bulbus glandis, the mucosa was undermined along the ventral abdominal wall. The undermined parietal preputial mucosa was sutured over exposed penis. The ventral abdominal skin was also undermined and sutured separately over mucosa. Skin was closed by simple interrupted pattern using silk. The dorsocranial aspect of mucosa, for the preputial orifice was left intact. Post-operatively Cefataxime @ 20mg/kg b.wt. intravenously for 5 days and Melonex (a) (Meloxicam) @ 0.5mg/kg b.wt. intravenously for 3 days were administered. Urinary incontinence was resolved after 15 days. The animal recovered uneventfully from the condition.
[FIGURE 1 OMITTED]
The report describes a case of hypospadia in a 3 year old intact dog with the external urethral orifice on ventral surface of penis rather than tip of glans.
The cause of hypospadias is not known, it is presumed that affected foetus may secret inadequate quantities of testosterone or that there may be inadequate conversion of testosterone to dihydrotestosterone in target tissues of urogenital sinus and external genitalia. The severity of defects present depends on degree of androgen insufficiency in additional exposure of male foetus to progesterone or anti androgens during gestation especially between 30 and 44 days (Moore, 1982 and Meyer-Wallen and Patterson, 1986).
Severe genetic defects including cryptochidism (McFarland and Deniz, 1961), absence of scrotum (Finco et al., 1979), bifid scrotum as observed in the present case and persistent Mullerian structures had been observed in dogs. However, chromosome analysis can be performed to differentiate hypospadias from true hermaphroditism (Adder and Hobson, 1998).
Surgical correction is usually not attempted because urethra cranial to abnormal orifice is deficient. The present case, although the urethral opening was 5 cm from tip of penis, it was patent on catheterization up to the urinary bladder. Other methods of treatment include reconstruction of urethra, removal of open prepuce, partial penile amputation and prescrotal or perineal urethrostomy and castration. The present case prepupial sheath was incomplete and hence a reconstructive surgery of penial prepupial sheath was done to cover the exposed dry penis (Finco et al., 1979, Hobson, 1983 and Hobson, 1998).
It is concluded that in less severe cases of hypospadias, an attempt should be made to surgically reconstruct the affected parts. The affected dogs should not be used for breeding purposes.
Adder, P.L. and Hobson, H.P. (1998). J. America. Anim. Hosp. Associa. 14: 721-27.
Finco, D.R., Thrall, R. and Duncan, J.R. (1979). Urinary system. In Canine Medicine. 4th Edn., Catcott EJ, editor. American Vet. Public. p. 489.
Hobson, H.P. (1983). In Current Techniques in Small animalSurgerry. First. Bojrab, M.J., Editor. Philadelphia: Lea and Febiger. Surgical procedures of penis. pp. 380.
Hobson, H.P. (1998). In Current Techniques in Small Animal Surgery. Fourth. Bojrab MJ, Ellison GW, Slocum B, Editor. Baltimore: Williams and Wilkins. Surgical procedures of penis. pp. 527-534.
McFarland, L.Z. and Deniz, E. (1961). J. America. Vet. Med. Associa. 139: 1099-1100.
Moore, K.L. (1982). Conditions related to intersexuality. In The Developing Human--Clinically Oriented Embryology. Third edition. Philadelphia: Saunders. p. 287.
Meyers--Wallen, V.N. and Patterson, D.F. (1986). In Current Therapy in Theriogenology. Second. Morrow DA, editor. Philadelphia: Saunders. Disorders of Sexual Development in the Dog. p. 567-573.
Gokul Krishanan (1), L. Nagarajan (2) and Harish Kulkarni (3)
Department of Veterinary Surgery and Radiology Madras Veterinary College Tamil Nadu Veterinary and Animal Sciences University (TANUVAS) Chennai--600051 (Tamil Nadu)
(1.) Assistant Professor
(2.) Professor, Department of Clinics
(3.) Assistant Professor, Department of TVCC, Veterinary College, Bidar and Corresponding author. E-mail: firstname.lastname@example.org
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|Author:||Krishanan, Gokul; Nagarajan, L.; Kulkarni, Harish|
|Date:||Jan 1, 2016|
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