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
Polypoid cystitis
- what is it?
- gross appearance?
- possible negative outcomes?
- Chronic cystitis with multiple polyps can be seen commonly in any species
- Grossly the mucosa is folded and/or forms villus-like projections
> polyps are composed of a core of proliferating connective tissue with numerous mononuclear leukocytes overlain by a layer of epithelium - if chronic > fibrosis can develop
- chronic insults to polyps can provide background for urothelial cell carcinoma to develop
- lesions can ulcerate > hematuria, obstruction
Bovine enzootic hematuria
- what is it?
- what problems does it cause?
- Chronic ingestion of bracken fern > hematuria
> with a hemorrhagic mucosa (‘cystitis’) and papillomas, fibromas, hemangiomas, and/or their malignant counterparts, urothelial (transitional) cell carcinoma and hemangiosarcoma
> Malignant forms can be locally invasive, but only 10 % of the epithelial tumours metastasize
> regionally problematic
Lower urinary tract tumours
- how common
- species?
- what type is most likely?
- type of disease / signs caused?
- uncommon
- dogs, cats, and cattle (enzootic hematuria)
- most common = urothelial cell carcinoma (UCC) aka transitional cell carcinoma (TCC)
> often are invasive and metastatic
> systemic disease with a silent primary
> can obstruct (esp in bitch)
epithelial tumours of the urinary tract other than UCC
- adenomas
- papillomas
- adenocarcinomas
- squamous cell carcinomas (SCC)
urinary SCC’s vs UCC’s - metastasis
Urinary SCCs are reported to be less likely to metastasize than UCCs.
Stromal tumours of the urinary tract
- what types
- malignancy?
- who is affected?
- usual signs / issues?
- leiomyomas and fibromas
> malignant counterparts very rare
<><> - Botryoid (like a bunch of grapes) rhabdomyosarcoma occurs in the urinary bladder, most commonly in young large breed dogs, especially St. Bernards
> The tumours often cause obstruction and are usually identified because of the clinical signs of obstruction
> If not diagnosed early, can metastasize
> botryoid rhabdomyosarcoma has been associated with hypertrophic osteopathy
