Page 217 - Problem-Based Feline Medicine

13 – THE CAT WITH DISCOLORED URINE 209
209

Clinical signs Clinical signs

Clinical signs are similar to other causes of lower uri- If uroliths are located in the lower urinary tract,
nary tract disease: hematuria, pollakiuria, stranguria stranguria, pollakiuria, inappropriate urination,
and urination in inappropriate places. hematuria and/or urethral obstruction may occur.

Most commonly occurs in cats less than 10 years of If uroliths are located in the upper urinary tract, renal
age; average age is 2–4 years. pain, hematuria or uremia (if bilateral) may be present.
Occurs with even frequency in male and female cats. Uremia is present with urethral obstruction or bilateral
ureteral obstruction.
May be associated with urethral plug formation and
obstruction in male cats. Clinical signs may also be absent with uroliths.

Diagnosis Diagnosis
Must be differentiated from other causes of lower uri- Microscopic examination of urine sediment reveals
nary tract disease such as urolithiasis and bacterial uri- RBCs.
nary tract infection.
Crystalluria may or may not be present. If present, they
In cats less than 10 years of age, it occurs in 55–70% may aid in estimating mineral composition (see page
of cases of lower urinary tract disease; in cats 213 for description of crystal appearance).
greater than 10 years of age, it occurs in 5–10% of
Most common mineral composition includes struvite
cases of lower urinary tract disease.
(magnesium ammonium phosphate hexahydrate) and
Diagnosis is made by excluding other causes of calcium oxalate; urate (purine), cystine, calcium phos-
lower urinary tract disease. phate, and drug metabolites have also been observed to
occur.
Urinalysis reveals hematuria (>5 RBC/hpf) without a
urinary tract infection; white blood cells are usually Struvite and calcium oxalate uroliths are usually radio-
present at < 5–10/hpf and urine culture is negative. dense; urate and cystine are usually radiolucent and
require contrast radiography or ultrasonography to
Crystals may or may not be present on urine sediment
identify.
examination.
Radiographs and ultrasonography of the lower urinary
tract are usually normal; however, bladder wall thick-
ening or intraluminal blood clots may be present. URINARY TRACT INFECTION CAUSING
HEMATURIA**
Cystoscopy often reveals small mucosal hemorrhages
called glomerulations, without identifying other dis-
Classical signs
eases processes.
● Hematuria, stranguria, pollakiuria, and/or
inappropriate urination (urinary bladder
infection).
UROLITHIASIS CAUSING HEMATURIA***
● Urinary tract infection may occur
secondary to another disease, and other
Classical signs
clinical signs may be present.
● Stranguria, pollakiuria, inappropriate ● Asymptomatic or associated with fever,
urination and/or urethral obstruction. renal pain, or uremia (upper urinary tract
● Renal pain, hematuria, or uremia if uroliths infection).
present in upper urinary tract.
See main reference on page 187 for details on urinary
See main reference on page 184 for details on urolithiasis. tract infections.