Page 195 - Problem-Based Feline Medicine

11 – THE CAT STRAINING TO URINATE 187

● Damage to the bladder mucosal defense barrier due
INFECTIOUS CYSTITIS/URETHRITIS*
to trauma (catheterization, surgery, uroliths) or
neoplasia.
Classical signs
● Changes in urine composition (alkaline pH, glu-
● Frequently seen trying to urinate cosuria).
(pollakiuria). ● Chronic renal failure.
● Straining with little urine passed (dysuria).
Infectious agents include:
● Blood-tinged urine (hematuria).
● Bacterial cystitis/urethritis (cystourethritis).
● Cat may urinate in inappropriate places.
– Rare in cats and most are aerobic infections.
– Common organisms cultured include Escherichia
coli, Staphlococcus intermedius, Streptococcus
Pathogenesis
spp., Proteus, Pasteurella, Klebsiella, Pseudo-
Inflammation of the feline urinary tract is rarely caused monas and Enterobacter. Occasionally Myco-
by an infectious agent. plasma and Ureaplasma are reported and these
organisms do not grow on routine culture
About 5–10% of cats with lower urinary tract disease
media.
have urinary tract infections, which may be primary
– Mycoplasma cultures should be considered if
or secondary.
pyuria is present but no aerobic bacterial
The prevalence of urinary tract infections increases growth occurs.
with age, being uncommon in young adult cats to mid- – Recurrent ascending urinary tract infections
dle age of either sex. occur in immunosuppressed cats (FeLV, FIV,
● Urinary tract infection accounts for less than 2% of diabetes mellitus), and are common in cats with
cases of lower urinary tract disease in cats from urethral incompetence, which occurs most fre-
1–10 years of age. quently following perineal urethrostomy.
● Of cats older than 10 years of age with signs of ● Viral
lower urinary tract disease, 46% had a positive –A herpesvirus has been isolated from cats with
urine culture and a further 17% had a positive cul- sterile lower urinary tract inflammation but its
ture associated with urolithiasis. Two thirds of cats significance is unclear.
with a positive culture not associated with urolithi- ● Fungal
asis had chronic renal failure. – Infections are rare and due to Candida albicans
● Of cats with chronic renal failure, 30% had one or Aspergillus fumigatus.
or more positive urine cultures over a period of 4–8 – Mainly reported in cats on long-term antibiotic
months which were all E. coli. therapy with impaired host defenses (perineal
urethrostomy and urine stasis).
Most bacterial infections in cats are secondary to other
● Parasitic
causes of lower urinary tract disease, perineal urethros-
– Rarely reported but include Capillaria feliscati
tomy, the use of indwelling urinary catheters or chronic
and Encephalitozoon cuniculi.
renal failure.
– Capillaria feliscati has been reported in
Predisposing causes of urinary tract infection Australia and USA. It is a trichurid nematode
include: that usually attaches superficially to the bladder
● Anatomical abnormalities (ectopic ureter, patent mucosa and so most cats are asymptomatic.
urachus, perineal urethrostomy). However, on rare occasions it may produce
● Urethral incompetence (usually associated with recurrent bouts of hematuria and dysuria.
perineal urethrostomy).
● Loss of mechanical washout of the bladder and ure-
Clinical signs
thra due to bladder atony, urolithiasis, painful
hindquarters and debility. Dysuria, pollakiuria with or without hematuria.