Introduction:
Urethral diverticula have been described in other species, and to our knowledge there is only one report of a urethral diverticulum in a breeding stallion (Diel de Amorim et al. 2014).
In human medicine, urethral diverticula are described as epithelized outpouchings of the urethral lumen into surrounding periurethral fascia (Crescenze et al. 2015; El-Nashar et al. 2014; Reeveset al. 2014). It is a rare condition that affects mainly adult women with a reported incidence between 1 and 6% (Crescenze et al. 2015; El-Nashar et al. 2014). There are only few reports of diverticula in males (Thakur et al. 2016; Cinman et al.2012; Popoola et al. 2009; El Ammari et al. 2012; Mohantyet al. 2014). Diverticula are congenital or acquired and the latter is the most frequent. Rupture of periurethral glands into the urethral lumen, secondary to repeated obstruction and infection is thought to be the main etiology for acquired cases (Huffman 1948) but trauma may also play an important role (Reeves et al. 2014). Most of the diverticula reported in human medicine are located in the mid-to-distal third of the urethra. This location reinforces the theory of ruptured periurethral glands, since these are draining in the distal one-third of the urethra (Lang et al.; MacKinnon et al.).
Reported clinical signs in humans are non-specific and include dysuria, dyspareunia, incontinency and/or discharge (Romanzi et al. 2000). They have also been reported to be incidental findings (Crescenzeet al. 2015; El-Nashar et al. 2014One-third of the patients have recurrent urinary tract infections (Ganabathi et al. 1994; Davis and Robinson 1970). To our knowledge only 4 cases have been described in small animals and clinical signs included: perineal swelling, dysuria, stranguria, urinary incontinence and urinary tract infections (Henry et al. 2018; Foster et al. 1999; Atilla 2018; Watanabe et al. 2015). Distal/penile urethral diverticula have been reported in goat kids and calfs and are frequently associated with hypospadias (Simon et al. 2010; Temi̇zsoylu 2005;Bokhari 2013; Sylla et al. 2019; Abd-El-Hady 2014; Maiti et al. 2018). The only case described in a stallion by Diel de Amorin et al. showed blood dripping from the penis after a breeding attempt. The stallion had a history of a previous history of breeding injury with a surgical repair of the urethra.
Diagnosis can be made in other species using cystourethroscopy, double balloon positive pressure urethrography, voiding cystourethrogram, Magnetic Resonance Imaging, computed tomography scan and transperineal and transvaginal ultrasound (Crescenze et al. 2015; Stav et al. 2008; Gugliotta et al. 2015; Romanzi et al. 2000; Kimet al. 1993; Ljungqvist et al. 2017; Ockrim et al.2009; Pathi et al. 2013; Dwarkasing et al. 2011; Blanderet al. 2001). Various surgical techniques have been described in human medicine (Greiman et al. 2019) and successful surgical therapy has been reported in other species (Henry et al. 2018; Foster et al. 1999; Atilla 2018; Watanabe et al. 2015; Simon et al. 2010; Temi̇zsoylu 2005; Bokhari 2013; Syllaet al. 2019; Abd-El-Hady 2014; Maiti et al. 2018). Conservative therapy has also been described (Lee and Fines 2005; Ellik 1957; Mizrahi and Bitterman 1988). This case report describes a unique case of 2 urethral diverticula in a 26-year-old gelding.