Page 213 - Problem-Based Feline Medicine

13. The cat with discolored urine

Joseph William Bartges

KEY SIGNS
● Red, pink, orange, brown, black, white, blue or colorless urine.

MECHANISM?
● Urine color other than yellow including red, orange, white, blue, brown and black is abnormal.
Red, brown or orange urine suggests blood, hemoglobin, myoglobin or bilirubin.
Cloudy or white urine suggests pus, lipid or crystals.
Pale yellow or colorless urine is associated with dilute urine and increased urine volume.
Blue or green urine is uncommon, and is usually associated with excretion of drugs or toxins.

WHERE?
● Urogenital tract – urine is formed in the kidney and is usually yellow.
Pigments that are filtered by the glomerulus may alter urine color.
Blood cells may alter urine color if added to urine after formation.

WHAT?
● Red, pink, orange, brown or black urine***

QUICK REFERENCE SUMMARY
Diseases causing discolored urine

MECHANICAL
● Urolithiasis causing hematuria*** (p 209)
*Occurs in 15–30% of cats with lower urinary tract disease; *struvite most common in young cats;
*calcium oxalate is most common in middle-aged or older cats; *nephroliths are often composed
of calcium oxalate.
NEOPLASIA
● Neoplasia causing hematuria* (p 210)
*urinary tract neoplasia is rare in cats; *renal neoplasia is often associated with renomegaly;
*hematuria may be the only clinical sign.

continued

205