| Normal urine is typically transparent and yellow or amber on visual inspection. The intensity of color is in part related to the volume of urine collected and concentration of urine produced; therefore, it should be interpreted in context of urine specific gravity (USG). Significant disease may exist when urine is normal in color. Abnormal urine color may be caused by presence of endogenous or exogenous pigments, but it does not provide specific information. Interpretation of
semiquantitative reagent strips, which are colorimetric tests, requires knowledge of urine color because discolored urine may result in a false-positive result. Equine urine may turn brown after a period of time. |
| Urine is typically clear but may become less transparent with pigmenturia, crystalluria, hematuria, pyuria, lipiduria, or when other compounds such as mucus are present. Depending on the cause, increased turbidity may disappear with centrifugation of the sample. |
| Normal urine has a slight odor of ammonia; however, the odor is dependent on urine concentration. Some species, such as cats and goats, have pungent urine odor because of urine composition. Bacterial infection may result in a strong odor due to pyuria; a strong ammonia odor may occur if the bacteria produce urease. |
