Veterinary Medicine - July 2008 - (Page 375)

Figure 1—Conﬁrming hematuria If pigmenturia suggestive of blood is reported or observed, use a urine dipstick colorimetric test to determine whether blood is present. If the result is positive, examine the urine sediment for RBCs. If the result is negative and the sample was obtained by cystocentesis or catheterization, repeat the test with voided urine. If RBCs are seen, the patient has hematuria. If RBCs are not seen, examine the patient’s plasma. If the result from a voided sample is negative, use the dipstick colorimetric test to determine whether bilirubin is present. If the plasma is pink, the patient likely has hemoglobinuria. If the plasma is clear, the patient likely has myoglobinuria or RBC lysis in the urine. Conﬁrm the myoglobinuria with a commercial laboratory test. If the dipstick test result is positive for bilirubin and the patient is a dog, check the urine speciﬁc gravity. If the dipstick test result is positive for bilirubin and the patient is a cat, the patient has bilirubinuria. If the dipstick test result is negative, test an additional urine sample for blood by urine dipstick or sediment examination. If the result is 1.020, the result is normal. If the result is > 1+ bilirubin with a urine speciﬁc gravity of < 1.020, the dog has bilirubinuria. If the additional sample has negative results, review the history and physical examination ﬁndings for evidence of drug-, food-, or toxin-related pigmenturia or an inherited source of pigmenturia. If no evidence of an abnormal pigmenturia source is found, the patient either has normal urine or idiopathic pigmenturia. pseudohematuria—urine discoloration from pigments derived from drugs such as doxorubicin, food dyes, toxins such as mercury, or inherited conditions such as porphyria—and review the patient’s historical and physical examination ndings.4 If you suspect pseudohematuria, persistent discoloration of urine supernatant after centrifugation may provide further evidence of this condition. If you cannot nd evidence of an abnormal exogenous or endogenous pigment resulting in discoloration, it is possible that the color is a normal manifestation of urochrome and urobilin (normal urine pigments) in a concen- trated urine sample. In this instance, the urine typically has a dark-yellow to brown hue. In rare instances, abnormal pigment in urine cannot be identi ed by standard evaluation methods and, if persistent, could be pursued by expanded laboratory testing. State veterinary diagnostic VETERINARY MEDICINE July 2008 375

Table of Contents Feed for the Digital Edition of Veterinary Medicine - July 2008

Veterinary Medicine - July 2008 Contents Leading Off Practical Matters Idea Exchange Clarification Dental Corner The Diagnostic Approach to Hematuria Guidelines for Evaluating Hypercalcemic Cats CE Form Advertiser Index Marketplace/Classifieds Mind Over Miller

Veterinary Medicine - July 2008

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