Ch313 - Congenital Lower Urinary Tract Disorders Flashcards
What is an ectopic ureter?
A congenital abnormality in which at least 1 ureteral opening is located distal (caudal) to the bladder trigone.
What are the two main types of ectopic ureters?
- Intramural (86-100% of cases in dogs) - tunnels submucosally through bladder/urethra wall
- Extramural - bypasses bladder and inserts directly into urethra, vagina, or uterus
Which breeds are predisposed to ectopic ureters?
Golden Retriever, Labrador Retriever, Newfoundland, Siberian Husky, Poodle, Soft Coated Wheaten Terrier, and Entlebucher Mountain Dog (confirmed hereditary)
What is the primary clinical sign of ectopic ureters?
Urinary incontinence, though some animals may show no clinical signs due to high urethral tone and retrograde flow of urine into the bladder
What is the preferred diagnostic method for ectopic ureters in female dogs vs male dogs/cats?
- Female dogs: Cystoscopy (100% sensitivity)
- Male dogs and cats: Computed tomographic excretory urography (CTEU)
What is a ureterocele?
A cystic dilatation of the submucosal portion of the distal ureter
What are the two types of ureteroceles?
- Orthotopic - ureterocele and ureteric opening located within bladder
- Ectopic - any portion of ureterocele located within urethra
What are the three types of urachal anomalies?
- Patent urachus - open communication between bladder and umbilicus
- Urachal cyst - isolated section with epithelial secretory lining
- Vesicourachal diverticulum - persistent communication of proximal urachus with bladder apex
What is bladder hypoplasia most commonly associated with?
It’s most commonly secondary to other conditions causing urinary incontinence in juvenile animals, such as ectopic ureters or congenital urethral sphincter mechanism incompetence
What is hypospadias?
A failure of fusion of the urogenital folds resulting in incomplete formation of the ventral aspect of the urethra
What is the difference between hypospadias and epispadias?
- Hypospadias: Incomplete formation of ventral urethra
- Epispadias: Incomplete formation of dorsal urethra
What are the main signs associated with urethrorectal/rectovaginal fistulae?
- Feces or urine exiting from incorrect orifice
- Possible perineal bulging if fecal material cannot pass
- Common urinary tract infections
- Hematuria, stranguria, and pollakiuria may occur
What are the three main vestibulovaginal junction anomalies?
- Vestibulovaginal stenosis
- Vestibulovaginal septal remnant (VVSR)
- Dual vagina
What is a vestibulovaginal septal remnant (VVSR)?
A vertical band of tissue resulting from retention of epithelium at the point of mesonephric duct fusion, ranging from thin lesions to thick bands extending into the vagina
What percentage of dogs with ectopic ureters also have vestibulovaginal septal remnants?
93% of dogs with ectopic ureters have concurrent VVSRs
What percentage of female dogs experience persistent urinary incontinence after ectopic ureter treatment?
35-63% of female dogs experience persistent incontinence after treatment
What is the success rate of treating ectopic ureters in male dogs?
Much better than females - 100% continence reported with laser ablation in one study of 4 dogs, and 82% continence rate reported in 16 male dogs treated with conventional surgery
What concurrent congenital abnormalities are commonly seen with ectopic ureters?
- Renal dysplasia/hypoplasia/aplasia
- Ureterocele
- Urethral hypoplasia
- Vestibulovaginal abnormalities
What secondary complications can develop with ectopic ureters?
- Hydronephrosis
- Hydroureter
- Bladder hypoplasia
- Recurrent urinary tract infections
What is the typical age of presentation for ectopic ureters?
- Dogs: Often <6 months of age, though males may present when older
- Cats: Mean age of 1.4 years
- Should remain on differential list lifelong for compatible clinical signs
What percentage of dogs with ectopic ureters have urinary tract infections? and what is the most common bacteria?
Up to 83% of female dogs and 36% of cats, most commonly due to E. coli
What is the sensitivity of ultrasound for diagnosing ectopic ureters?
95% in a recent study, but significantly lower sensitivities have been reported due to operator dependence
What are the treatment options for intramural ectopic ureters?
- Preferred: Transurethral cystoscopic-guided laser ablation
- Alternative: Cystoscopic-guided scissor transection
- Surgical correction (intravesicular neoureterostomy or extravesicular ureteral re-implantation)
What are the clinical signs of ureteroceles?
- May be asymptomatic
- Lower urinary tract signs (stranguria, pollakiuria, urinary incontinence)
- Abdominal pain if upper urinary tract obstruction or infection present
