urinary system notes pt 3 Flashcards
Hypoplasia/aplasia of the ureters can result in what?
- if unilateral, usually results in hydronephrosis
> unless the ipsilateral kidney is also aplastic, in which case it can be clinically silent
<><> - Bilateral aplasia (or bilateral severe hypoplasia) is obviously not compatible with life
arguably the most important developmental abnormality of the ureters
ectopic ureters
issues with ectopic ureters
- more prone to obstructions and lack proper vesicoureteral valves (one-way valve found where the ureters normally enter the bladder)
> animals are predisposed to ascending infection leading to pyelitis and/or pyelonephritis
most common abnormality of the lower urinary tract? issues with this?
- patent urachus
> fetal urachus (connection from bladder to umbilicus) fails to close - can either rupture (leading to uroperitoneum) or become infected +/- lead to abscess formation (ironically one cause of failure of closure of the urachus is inflammation)
- Urachal patency can also lead to urine dribbling out of the umbilicus in some situations
most common urethral abnormalities? issues?
fistulae (urethrorectal or urethrovaginal)
- In males the urethra most commonly communicates with the rectum (and thus dogs pee from the rectum)
- in females it usually opens into the vagina
- altered anatomy increases the risk of urinary tract infections
> but often incidental findings
most important condition of the lower urinary tract aside from developmental abnormalities
- inflammation
> cystitis,
> ureteritis (usually with systitis)
> urethritis (usually with obstructive urolithiasis)
the common clinical term of cystitis refers to :
(though not really what it should mean)
- clinical syndrome of stranguria and polyuria with or without hematuria
> There are many causes of disease that result in the clinical signs of ‘cystitis’ without it being infectious or inflammatory
bladder - body’s defences for cystitis
- bacteria are usually cleared with the normal flow of urine
- Tamm-Horsfall mucoprotein, which may prevent bacterial adherence by binding to adhesins
- locally produced IgA,
- IgG,
- surface glycosaminoglycans
- urinary oligosaccharides which also interfere with bacterial adherence
- antimicrobial peptides such as cathelicidin
<><><><> - desquamation of urothelial cells also helps prevent infection
predisposing factors for UTI
- Trauma to the bladder urothelium
- stagnation of urine due to obstruction or incomplete voiding
is animal urine a good medium for bacterial growth? why?
- not a good medium for bacterial growth due to its acidity and high osmolality
> (unlike human urine)
The majority of bacteria causing cystitis come from where?
- up the urethra, and most of these are originally from the rectal flora
common types of bacteria implicated in cystitis for all species
- E. coli
- Proteus vulgaris,
- streptococci
- staphylococci
Feline lower urinary tract disease (FLUTD) can be associated with:
- UTIs (viral, bacterial, or fungal origin)
- uroliths,
- urethral plugs
- congenital or anatomic defects of bladder or urethra
- or iatrogenic
Idiopathic cystitis
- what is it? possible pathogenesis?
clinical signs of cystitis without infections, no uroliths (macro or microlithiasis), or history of urethral obstruction
<><><><>
- Damage to the lining of the bladder and loss of the locally produced glycosaminoglycans that normally stop urine imbibition into the submucosa
> edema and hemorrhage, and erosion of the epithelium
> elf- perpetuation of the process
<><><><>
- Initial damage may be due to:
> infection (infectious/bacterial cystitis)
> urolithiasis
> urethral obstruction
> chemical (cyclophosphamide, bracken fern)
> unknown
- Grossly, all have a swollen and sometimes hemorrhagic mucosa.
Lymphonodular cystitis
- what is this?
- gross appearance
- lymphoid follicular hyperplasia in chronic infectious cystitis
- Grossly, the mucosa is covered with myriad small (~ 1 mm) grey-white nodules that occasionally are surrounded by hyperaemic mucosa
> nodules are composed of proliferating lymphocytes
