In other species: horse

Categories: Renal / urinary system phene

Mendelian trait/disorder: no

Mode of inheritance: Multifactorial

Disease-related: yes

Key variant known: no

Inheritance: From records of 1611 Entlebucher Mountain Dogs, Fritsche et al. (2013) estimated heritability of this disorder to be 65%, with some evidence of involvement of a gene of large effect.

Clinical features: Ectopic ureter (EU) is a congenital malformation where one or both ureters enter the bladder in an abnormal anatomical position, outside of the trigone area. The ureters enter on the bladder neck, urethra, uterus or vagina (Reichler et al., 2012). Ectopic ureters can be classified in intramural and extramural, depending on if they bypass the bladder or not. The extramural EU bypasses the bladder completely and opens into the possible abnormal anatomical structures, while the intramural enters the bladder wall in the correct anatomic position (trigone area) but extends within the bladder to then open into an abnormal position. Urinary incontinence is the most common clinical sign of EU and affected dogs often present at a very young age (Koie et al., 2000), with males also commonly showing signs of urinary incontinence at a more advanced age (Holt and Moore, 1995). Diagnosis of EU is best achieved by different imaging methods such as intravenous urography and ultrasonography (Lamb and Gregory, 1998; Koie et al., 2000; Taylor et al., 2022). Treatment involves surgical reposition of ectopic ureter into the bladder and medication for incontinence when needed (Koie et al., 2000). [IT thanks DVM student Ginady Martinez Casiano, who provided the basis of this contribution in April 2022]

Pathology: Urinary tract infections related to urinary incontinence are common in presentation of dogs with EU (Fritsche et al., 2013). These result in inflammation throughout the urinary tract (e.g. urethritis, cystitis, ureteritis, pyelonephritis). In a large portion of cases, EU has also been associated with other urogenital conformational or functional abnormalities such as hydronephrosis, dilated ureters, vestibulo-vaginal malformations, hypoplastic bladder or kidney, congenital urethral sphincter mechanism incompetence (USMI), ureterocele, renal dysgenesis, pelvic bladder and others (Reichler et al., 2012; Dekerle et al., 2022). [IT thanks DVM student Ginady Martinez Casiano, who provided the basis of this contribution in April 2022]

Breed: Entlebucher Mountain Dog (Dog) (VBO_0200503).
Breeds in which the phene has been documented. (If a likely causal variant has been documented for the phene, see the variant table breeds in which the variant has been reported).