Page 223 - Problem-Based Feline Medicine

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13 – THE CAT WITH DISCOLORED URINE 215

It may be present with lipid metabolism disorders such Diagnosis
as idiopathic hyperlipidemia, inherited hyperchylomi-
Urine is pale yellow or colorless.
cronemia and idiopathic feline hepatic lipidosis.
Urine specific gravity is isosthenuric (1.008–1.014) or
hyposthenuric (< 1.008).
Diagnosis
Pale yellow or colorless urine may be normal with con-
Lipid droplets identified on microscopic sediment sumption of a large quantity of water, consumption of a
examination. low-protein diet or administration of fluids or agents
that induce diuresis.
Lipid droplets may be stained using Sudan IV.
Pale yellow or colorless urine should be considered
abnormal if present with azotemia or dehydration.
PALE YELLOW OR COLORLESS URINE

DILUTE URINE*** BLUE OR GREEN URINE

Classical signs DRUG DISCOLORATION
● Polyuria and polydipsia are usually
Classical signs
present.
● Most common causes of polyuria in cats ● Blue or green urine.
are renal failure, diabetes mellitus and ● History of administration of drugs
hyperthyroidism. especially methylene blue.

See main reference on page 231 for details (The Cat
With Polyuria and Polydipsia). Clinical signs

A number of drugs and dyes cause blue or green urine
but few are used in cats.
Clinical signs
Blue or green urine occurs in cats following methylene
Pale yellow or colorless urine implies increased urine blue use. In humans amitriptyline and riboflavin have
volume; therefore, polyuria and polydipsia are usu- been reported to cause blue or green urine.
ally present.
Polysystemic signs such as vomiting, weight loss and
Diagnosis
anorexia may be present with some diseases (renal fail-
ure and diabetes mellitus) and increased appetite may Careful questioning of the owner will usually identify
occur with hyperthyroidism and diabetes mellitus. the drug causing the urine discoloration.

RECOMMENDED READING
Bartges JW. Discolored urine. In: Ettinger SJ, Feldman EC (eds) Textbook of Small Animal Internal Medicine.
Philadelphia, WB Saunders, 2000, pp 96–99.
Bartges JW. Diseases of the urinary bladder. In: Birchard S, Sherding R (eds) WB Saunders Manual of Small Animal
Practice. Philadelphia, WB Saunders, 2000, pp 943–957.