Ch 43 Urethra Flashcards
What are the 3 areas/sections of the male urethra?
prostatic, membranous, penile
How do the canine and feline prostatic urethra differ?
The prostatic urethra is surrounded completely by the prostate gland in the dog, although only dorsolaterally in the cat.
The membranous urethra is enveloped by________ and __________.
cavernous tissue, the urethralis muscle
The penile urethra extends from ____________ to the tip of the penis.
the ischial arch
Which part of the urethra is also known as the cavernous urethra?
penile urethra (because the majority of it is encased by erectile tissues of the penis)
The female urethra is ______ than in males.
shorter and wider
Where is the muscular urethral sphincter located in female dogs?
at the vestibulovaginal junction
What is located at the vestibulovaginal junction in dogs?
a muscular urethral sphincter
The feline bladder is typically intraabdominal / intrapelvic, with a long/short urethra.
intraabdominal, long
What are the parts of a feline urethra?
relatively long prepelvic part, which extends between the neck of the urinary bladder and the pelvic urethra
Which contrast medium should be used for retrograde urethrography, and what concentration?
iodinated, water-soluble contrast, 150 mg I/mL
How should the urinary bladder be for optimal contrast urethrography?
distended, to provide counterpressure to contrast injection, to allow maximal urethral distention
Maximum time to inflate foley catheter within urethra for a contrast urethrography?
15 minutes
Which urethra portion is wider - the membranous or the prostatic?
Prostatic
How much contrast for a retrograde urethrography in a MALE cat/dog?
5-20 ml, radiographs taken during last 1-2 mL
Which portion of the urethra has variable diameter and which is generally uniform, in dogs?
prostatic/membranous (or in cats: pelvic) - variable
penile - uniform
How much contrast for a retrograde urethrography in a FEMALE cat/dog?
5-10 mL (less than male, it is shorter)
Vaginocystourethrography in a normal female dog
A Foley catheter is in the vestibule and insufflated. As contrast medium is injected, the more cranial aspect of the vagina (white arrows) fills, followed by filling of the urethra (black arrows). Smooth, distinct mucosal margins of the urethra are seen.
Vaginocystourethrography in a normal female cat
A Foley catheter is in the vestibule and insufflated. As contrast medium is injected, the more cranial aspect of the vagina (white arrows) fills, followed by filling of the urethra (black arrows). Smooth, distinct mucosal margins of the urethra are seen.
Where do urethral calculi lodge in male dogs?
at regions of luminal narrowing or restriction: the ischial arch and base of the os penis.
How do you distinguish air bubbles (iatrogenic during urethrography) from calculi?
Air bubbles: smooth, round, do not distend the urethra and do not remain with subsequent contrast administration
Where do urethral calculi lodge in male cats?
In male cats with urethral obstruction secondary to sandy mineral calculi, a mineral plug may be seen in the penile urethra
What can have a similar appearance to calculi (irregularly marginated) on contrast urethrography? how do you differentiate?
blood clots, inconsistent presence with repeat contrast administration.
*air bubbles are smoothly marginated and round
A nipple is superimposed on the penile urethra (white arrow)
Separate center of ossification at the tip of the os penis (white arrow)
Os penis (white arrow) in a male cat.
Where would a separate center of ossification of the os penis be present in a male dog?
cranial (distal) aspect
What is more common - urethral inflammation or neoplasia?
Neoplasia; e.g. extension from bladder TCC or prostatic carcinoma, or primary urethral (less common)
Signalment of granulomatous urethritis, most frequently?
female neutered dogs
Differentials for urethral stricture
spasm - transient, physiological
inadequate distension - lack of volume or pressure
What’s the most common cause of urethral rupture in dogs/cats?
pelvic trauma
which signalment has this condition reported?
2y MN Golden retriever
c) Fully distended to allow maximal urethral distension
b) The ischial arch
False - they can have a separate cranial one though
C: Separate centre of ossification of the os penis
A: Membranous urethra
B: False
B: Urethrolith
Ischial arch and base of os penis
b) Osteocollagenous retention cysts are rare form of cyst, secondary to cystic hypertrophy
